Monroe Capital (MRCC) 10-Q 8 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 07, 2023
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	814-00866
Entity Registrant Name	MONROE CAPITAL CORPORATION
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	27-4895840
Entity Address, Address Line One	311 South Wacker Drive, Suite 6400
Entity Address, City or Town	Chicago
Entity Address State Or Province	IL
Entity Address, Postal Zip Code	60606
City Area Code	312
Local Phone Number	258-8300
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	MRCC
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		21,666,340
Entity Central Index Key	0001512931
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONSOLIDATED STATEMENTS OF ASSE

CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
ASSETS
Total investments, at fair value (amortized cost of: $536,795 and $579,307, respectively)	$ 518,284	$ 541,040
Cash	5,324	5,450
Unrealized gain on foreign currency forward contracts		1,507
Interest and dividend receivable	18,627	16,457
Other assets	301	541
Total assets	542,536	564,995
Debt:
Total debt	331,100	334,600
Less: Unamortized deferred financing costs	(3,566)	(4,486)
Total debt, less unamortized deferred financing costs	327,534	330,114
Interest payable	1,621	3,041
Management fees payable	2,140	2,221
Incentive fees payable	1,355	1,380
Accounts payable and accrued expenses	2,293	3,220
Directors' fees payable	38
Total liabilities	334,981	339,976
Net assets	207,555	225,019
Commitments and contingencies
ANALYSIS OF NET ASSETS
Common stock, $0.001 par value, 100,000 shares authorized, 21,666 and 21,666 shares issued and outstanding, respectively	22	22
Capital in excess of par value	298,700	298,700
Accumulated undistributed (overdistributed) earnings	(91,167)	(73,703)
Total net assets	$ 207,555	$ 225,019
Net asset value per share	$ 9.58	$ 10.39
Revolving credit facility
Debt:
Total debt	$ 201,100	$ 204,600
2026 Notes
Debt:
Total debt	130,000	130,000
Non-controlled/non-affiliate company investments
ASSETS
Total investments, at fair value (amortized cost of: $536,795 and $579,307, respectively)	400,117	418,913
Non-controlled affiliate company investments
ASSETS
Total investments, at fair value (amortized cost of: $536,795 and $579,307, respectively)	84,898	86,618
Controlled affiliate company investments
ASSETS
Total investments, at fair value (amortized cost of: $536,795 and $579,307, respectively)	$ 33,269	$ 35,509

CONSOLIDATED STATEMENTS OF AS_2

CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES
Amortized Cost	$ 536,795	$ 579,307
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	21,666	21,666
Common stock, shares outstanding	21,666	21,666

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Investment income:
Payment-in-kind interest income			$ 7,193	$ 4,458
Total investment income	$ 15,643	$ 15,916	48,794	41,402
Operating expenses:
Interest and other debt financing expenses	5,874	4,263	17,178	11,961
Base management fees	2,140	2,222	6,503	6,834
Incentive fees	1,355	1,565	4,493	2,747
Professional fees	189	212	541	740
Administrative service fees	228	275	707	908
General and administrative expenses	304	216	793	722
Directors' fees	38	35	113	109
Operating expenses before base management fee and incentive fee waivers	10,128	8,788	30,328	24,021
Base management fee waivers				(55)
Incentive fee waivers				(525)
Total operating expenses, net of base management fee and incentive fee waivers	10,128	8,788	30,328	23,441
Net investment income before income taxes	5,515	7,128	18,466	17,961
Income taxes, including excise taxes	95	868	495	1,289
Net investment income	5,420	6,260	17,971	16,672
Net realized gain (loss):
Extinguishment of debt				(1,039)
Foreign currency forward contracts		38	1,756	69
Foreign currency and other transactions	(4)	(1)	(135)	(38)
Net realized gain (loss)	26	(1,630)	(37,433)	(2,758)
Net change in unrealized gain (loss):
Unrealized gain (loss) of investments			19,756	(22,847)
Foreign currency forward contracts		863	(1,507)	1,503
Foreign currency and other transactions	1			164
Net change in unrealized gain (loss)	(5,682)	(5,379)	18,249	(21,180)
Net gain (loss)	(5,656)	(7,009)	(19,184)	(23,938)
Net increase (decrease) in net assets resulting from operations	$ (236)	$ (749)	$ (1,213)	$ (7,266)
Per common share data:
Net investment income per share - basic (in dollars per share)	$ 0.25	$ 0.29	$ 0.83	$ 0.77
Net investment income per share - diluted (in dollars per share)	0.25	0.29	0.83	0.77
Net increase (decrease) in net assets resulting from operations per share - basic (in dollars per share)	(0.01)	(0.03)	(0.06)	(0.33)
Net increase (decrease) in net assets resulting from operations per share - diluted (in dollars per share)	$ (0.01)	$ (0.03)	$ (0.06)	$ (0.33)
Weighted average common shares outstanding - basic (in shares)	21,666	21,666	21,666	21,666
Weighted average common shares outstanding - diluted (in shares)	21,666	21,666	21,666	21,666
Non-controlled/non-affiliate company investments
Investment income:
Interest income	$ 11,858	$ 9,383	$ 34,782	$ 26,030
Payment-in-kind interest income	649	738	2,240	2,039
Dividend income	65	103	317	267
Fee income	(836)	412	(356)	1,604
Total investment income	11,736	10,636	36,983	29,940
Net realized gain (loss):
Realized gain (loss) on investments	30	(1,666)	(39,054)	(1,749)
Net change in unrealized gain (loss):
Unrealized gain (loss) of investments	(3,346)	(1,049)	24,591	(12,281)
Non-controlled affiliate company investments
Investment income:
Interest income	1,174	3,830	4,006	6,202
Payment-in-kind interest income	1,781	502	4,953	2,419
Dividend income	52	48	152	141
Total investment income	3,007	4,380	9,111	8,762
Net realized gain (loss):
Realized gain (loss) on investments		(1)		(1)
Net change in unrealized gain (loss):
Unrealized gain (loss) of investments	(1,061)	(4,186)	(2,595)	(5,485)
Controlled affiliate company investments
Investment income:
Dividend income	900	900	2,700	2,700
Total investment income	900	900	2,700	2,700
Net change in unrealized gain (loss):
Unrealized gain (loss) of investments	$ (1,276)	$ (1,007)	$ (2,240)	$ (5,081)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
CHANGES IN NET ASSETS
Balances at the beginning	$ 213,208	$ 232,121	$ 225,019	$ 249,471
Balances at the beginning (in shares)			21,666
Net investment income	5,420	6,260	$ 17,971	16,672
Net realized gain (loss)	26	(1,630)	(37,433)	(2,758)
Net change in unrealized gain (loss)	(5,682)	(5,379)	18,249	(21,180)
Distributions to stockholders	(5,417)	(5,416)	(16,251)	(16,249)
Balances at the end	$ 225,019	225,956	$ 225,019	225,956
Balances at the end (in shares)	21,666		21,666
Common Stock
CHANGES IN NET ASSETS
Balances at the beginning	$ 22	$ 22	$ 22	$ 22
Balances at the beginning (in shares)	21,666	21,666	21,666	21,666
Net realized gain (loss)	$ 0		$ 0
Balances at the end	$ 22	$ 22	$ 22	$ 22
Balances at the end (in shares)	21,666	21,666	21,666	21,666
Capital in excess of par value
CHANGES IN NET ASSETS
Balances at the beginning	$ 298,700	$ 298,687	$ 298,700	$ 298,687
Net realized gain (loss)	0		0
Balances at the end	298,700	298,687	298,700	298,687
Accumulated undistributed (overdistributed) earnings
CHANGES IN NET ASSETS
Balances at the beginning	(85,514)	(66,588)	(73,703)	(49,238)
Net investment income	5,420	6,260	17,971	16,672
Net realized gain (loss)	26	(1,630)	(37,433)	(2,758)
Net change in unrealized gain (loss)	(5,682)	(5,379)	18,249	(21,180)
Distributions to stockholders	(5,417)	(5,416)	(16,251)	(16,249)
Balances at the end	$ (91,167)	$ (72,753)	$ (91,167)	$ (72,753)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net Income (Loss)	$ (1,213)	$ (7,266)
Adjustments to reconcile net increase (decrease) in net assets resulting from operations to net cash provided by (used in) operating activities:
Net realized (gain) loss on investments	39,054	1,750
Net realized (gain) loss on extinguishment of debt		1,039
Net realized (gain) loss on foreign currency forward contracts	(1,756)	(69)
Net realized (gain) loss on foreign currency and other transactions	135	38
Net change in unrealized (gain) loss on investments	(19,756)	22,847
Net change in unrealized (gain) loss on foreign currency forward contracts	1,507	(1,503)
Net change in unrealized (gain) loss on foreign currency and other transactions		(164)
Payment-in-kind interest income	(7,193)	(4,458)
Net accretion of discounts and amortization of premiums	(857)	(872)
Purchases of investments	(52,220)	(94,275)
Proceeds from principal payments, sales of investments and settlement of forward contracts	65,519	128,752
Amortization of deferred financing costs	977	1,613
Changes in operating assets and liabilities:
Interest and dividend receivable	(2,170)	(5,204)
Other assets	205	(18)
Interest payable	(1,420)	(1,999)
Management fees payable	(81)	(232)
Incentive fees payable	(25)	1,130
Accounts payable and accrued expenses	(927)	853
Directors' fees payable	38	35
Net cash provided by (used in) operating activities	19,817	41,997
Cash flows from financing activities:
Payments of deferred financing costs	(57)	(81)
Stockholder distributions paid, net of stock issued under the dividend reinvestment plan of $0 and $0, respectively	(16,251)	(16,249)
Net cash provided by (used in) financing activities	(19,808)	(52,929)
Net increase (decrease) in Cash and Restricted cash	9	(10,932)
Effect of foreign currency exchange rates	(135)	(20)
Cash and Restricted cash, beginning of period	5,450	18,081
Cash and Restricted cash, end of period	5,324	7,129
Supplemental disclosure of cash flow information:
Cash interest paid during the period	17,512	12,238
Cash paid for income taxes, including excise taxes during the period	390	578
Revolving credit facility
Cash flows from financing activities:
Proceeds from borrowings	79,800	143,900
Repayments of debt	$ (83,300)	(123,599)
SBA debentures payable
Cash flows from financing activities:
Repayments of debt		$ (56,900)

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Reconciliation of cash and restricted cash
Cash	$ 5,324	$ 5,450	$ 7,129	$ 2,622
Restricted cash				15,459
Total cash and restricted cash shown on the Consolidated Statements of Cash Flows	$ 5,324	$ 5,450	$ 7,129	$ 18,081

CONSOLIDATED SCHEDULE OF INVEST

CONSOLIDATED SCHEDULE OF INVESTMENTS - USD ($) $ in Thousands	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2022	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Type [Extensible Enumeration]		mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember		mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember
Amortized Cost		$ 536,795	$ 579,307
Fair Value		$ 518,284	$ 541,040
% of Net Assets		249.70%	240.40%
Investment, Identifier [Axis]: 360 Holdco, Inc. ( Delayed Draw), Senior Secured Loans, due 8/2/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: 360 Holdco, Inc., Senior Secured Loans, due 8/2/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A P C O Worldwide, Inc, Equity Securities, Class A voting common stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:APCOWorldwideIncMember	mrcc:APCOWorldwideIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Nov. 01, 2017	Nov. 01, 2017
Amortized Cost		$ 395	$ 395
Fair Value		$ 1,098	$ 921
% of Net Assets		0.50%	0.40%
Number of shares held		100
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held			100
Investment, Identifier [Axis]: A Q Carver Buyer, Inc., Senior Secured Loans, due 9/23/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A S G I I, L L C ( Delayed Draw), Unitranche Secured Loans, 5/25/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ASGIILLCMember	mrcc:ASGIILLCMember
Investment, Type [Extensible Enumeration]		Unitranche Secured Loans	Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.40%	6.25%
Interest Rate		11.77%	10.67%
Acquisition Date		May 25, 2022	May 25, 2022
Maturity		May 25, 2028	May 25, 2028
Principal		$ 285	$ 285
Amortized Cost		140	51
Fair Value		$ 140	$ 51
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: A S G I I, L L C, Unitranche Secured Loans, due 5/25/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ASGIILLCMember	mrcc:ASGIILLCMember
Investment, Type [Extensible Enumeration]		Unitranche Secured Loans	Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.40%	6.25%
Interest Rate		11.77%	10.67%
Acquisition Date		May 25, 2022	May 25, 2022
Maturity		May 25, 2028	May 25, 2028
Principal		$ 1,900	$ 1,900
Amortized Cost		1,868	1,865
Fair Value		$ 1,900	$ 1,900
% of Net Assets		0.90%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Delayed Draw), Senior Secured Loans, due 12/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Revolver), Senior Secured Loans, due 12/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C, Senior Secured Loans, due 12/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Ad Theorent Holding Company, Inc. Equity Securities, common stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AdTheorentHoldingCompanyIncMember	mrcc:AdTheorentHoldingCompanyIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 22, 2016	Dec. 22, 2016
Amortized Cost		$ 113	$ 114
Fair Value		$ 229	$ 294
% of Net Assets		0.10%	0.20%
Number of shares held		177,362	177,362
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 12/21/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcDelayedDrawMember	mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		9.26%	10.26%
Interest rate paid in cash			13.77%
Interest rate paid in kind		14.65%	1%
Acquisition Date		Dec. 21, 2022	Dec. 21, 2022
Maturity		Dec. 21, 2027	Dec. 21, 2027
Principal		$ 667	$ 667
Amortized Cost		293
Fair Value		$ 293
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 3/16/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.10%
Interest rate paid in kind		13.42%
Acquisition Date		Aug. 29, 2023
Maturity		Mar. 16, 2027
Principal		$ 155
Amortized Cost		104
Fair Value		$ 107
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Amelia Holding II, LLC (Revolver), Due 12/21/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcRevolverMember	mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		10.26%	10.26%
Interest rate paid in cash		14.65%	13.77%
Interest rate paid in kind		1%	1%
Acquisition Date		Dec. 21, 2022	Dec. 21, 2022
Maturity		Dec. 21, 2027	Dec. 21, 2027
Principal		$ 133	$ 133
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Amelia Holding II, LLC, Due 12/21/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcMember	mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		10.26%	10.26%
Interest rate paid in cash		14.65%	13.77%
Interest rate paid in kind		1%	1%
Acquisition Date		Dec. 21, 2022	Dec. 21, 2022
Maturity		Dec. 21, 2027	Dec. 21, 2027
Principal		$ 2,016	$ 2,000
Amortized Cost		1,963	1,940
Fair Value		$ 2,016	$ 1,940
% of Net Assets		1.10%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Dec. 21, 2022
Maturity		Dec. 21, 2032
Fair Value		$ 28
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Number of units held		0.1
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities, Warrant
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Dec. 21, 2022
Maturity			Dec. 21, 2032
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			true
Warrants to Purchase Percentage of Equity			0.10%
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Delayed Draw), Senior Secured Loans, due 6/10/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember	mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	us-gaap:PrimeRateMember
Spread Above Index		12%	12%
Interest rate paid in cash		18.50%	17.50%
Interest rate paid in kind		2%	2%
Acquisition Date		Jun. 10, 2022	Jun. 10, 2022
Maturity		Jun. 10, 2025	Jun. 10, 2025
Principal		$ 1,377	$ 1,689
Amortized Cost		1,254	1,521
Fair Value		$ 1,293	$ 1,539
% of Net Assets		0.60%	0.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Revolver), Senior Secured Loans, due 6/10/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember	mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	us-gaap:PrimeRateMember
Spread Above Index		12%	12%
Interest rate paid in cash		18.50%	17.50%
Interest rate paid in kind		2%	2%
Acquisition Date		Jun. 10, 2022	Jun. 10, 2022
Maturity		Jun. 10, 2025	Jun. 10, 2025
Principal		$ 500	$ 500
Amortized Cost		123	121
Fair Value		$ 123	$ 118
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C, Equity Securities, Warrants
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember	mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 10, 2022	Jun. 10, 2022
Maturity		Jun. 10, 2032	Jun. 10, 2032
Amortized Cost		$ 42	$ 42
Fair Value		$ 56	$ 69
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Warrants to Purchase Percentage of Equity		0.20%	0.20%
Investment, Identifier [Axis]: American Community Homes, Inc. ( Revolver), Senior Secured Loans Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.11%	8.11%
Interest rate paid in kind		13.43%	12.44%
Acquisition Date		Mar. 30, 2020	Mar. 30, 2020
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 2,500	$ 2,500
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities Due 12/18/2024, Warrants
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value					$ 264
Number of shares held		4,940
Warrants to Purchase Percentage of Equity				22.30%
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities, Common Stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 29, 2022	Dec. 29, 2022
Principal		$ 0
% of Net Assets		0%	0%
Number of shares held			4,940
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	false
Percentage of units held		4,940%
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Acquisition Date 3/29/2019
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 3,381	$ 3,694	$ 3,728	4,357
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.11%	8.11%
Interest rate paid in kind		13.43%	12.44%
Acquisition Date		Mar. 29, 2019	Mar. 29, 2019
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 5,121	$ 4,640
Amortized Cost		5,121	4,640
Fair Value		$ 3,381	$ 3,694
% of Net Assets		1.60%	1.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Acquisition Date 8/10/2018
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 1,826	$ 1,996	2,014	3,164
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.11%	8.11%
Interest rate paid in kind		13.43%	12.44%
Acquisition Date		Aug. 10, 2018	Aug. 10, 2018
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 2,766	$ 2,507
Amortized Cost		2,766	2,507
Fair Value		$ 1,826	$ 1,996
% of Net Assets		0.90%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Acquisition Date 7/22/2014
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 8,193	$ 8,953	9,034	10,457
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.11%	8.11%
Interest Rate			12.44%
Interest rate paid in kind		13.43%
Acquisition Date		Jul. 22, 2014	Jul. 22, 2014
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 12,411	$ 11,246
Amortized Cost		12,411	11,246
Fair Value		$ 8,193	$ 8,953
% of Net Assets		3.90%	4%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Acquisition Date 12/30/2019
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]
Fair Value		$ 77	$ 85	85	99
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.11%	8.11%
Interest rate paid in kind		13.43%	12.44%
Acquisition Date		Dec. 30, 2019	Dec. 30, 2019
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 117	$ 106
Amortized Cost		117	106
Fair Value		$ 77	$ 85
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Acquisition Date 9/30/2019
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 16	$ 17	18	20
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.11%	8.11%
Interest rate paid in kind		13.43%	12.44%
Acquisition Date		Sep. 30, 2019	Sep. 30, 2019
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 24	$ 22
Amortized Cost		24	22
Fair Value		$ 16	$ 17
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Acquisition Date 5/24/2017
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 497	$ 543	548	634
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.11%	8.11%
Interest rate paid in kind		13.43%	12.44%
Acquisition Date		May 24, 2017	May 24, 2017
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 752	$ 682
Amortized Cost		752	682
Fair Value		$ 497	$ 543
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Acquisition Date 7/22/2014
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 4,030	$ 4,258	4,249	4,753
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Due 12/31/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		12.61%	14.61%
Interest rate paid in kind		17.93%	18.94%
Acquisition Date		Jul. 22, 2014	Jul. 22, 2014
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 6,105	$ 5,348
Amortized Cost		6,105	5,348
Fair Value		$ 4,030	$ 4,258
% of Net Assets		2%	1.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Aras Corporation ( Revolver), Senior Secured Loans, due 4/13/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArasCorporationMember	mrcc:ArasCorporationMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Spread Above Index		5.50%	6.50%
Interest Rate		14%
Interest rate paid in cash			9.50%
Acquisition Date		Apr. 13, 2021	Apr. 13, 2021
Maturity		Apr. 13, 2027	Apr. 13, 2027
Principal		$ 150	$ 150
Amortized Cost		110	50
Fair Value		$ 110	$ 50
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Aras Corporation, Senior Secured Loans, due 4/13/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArasCorporationMember	mrcc:ArasCorporationMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.90%	7%
Interest rate paid in cash		8.95%	7.16%
Interest rate paid in kind		3.25%	3.75%
Acquisition Date		Apr. 13, 2021	Apr. 13, 2021
Maturity		Apr. 13, 2027	Apr. 13, 2027
Principal		$ 2,214	$ 2,155
Amortized Cost		2,193	2,127
Fair Value		$ 2,231	$ 2,167
% of Net Assets		1.10%	1%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, One, due 3/16/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.85%
Interest rate paid in kind		13.17%
Acquisition Date		Mar. 16, 2021
Maturity		Mar. 16, 2027
Principal		$ 4,572
Amortized Cost		4,482
Fair Value		$ 2,419
% of Net Assets		1.10%
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, Two, due 3/16/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.10%
Interest Rate		13.42%
Acquisition Date		Jul. 14, 2023
Maturity		Mar. 16, 2027
Principal		$ 155
Amortized Cost		150
Fair Value		$ 155
% of Net Assets		0.10%
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Arcstor Midco, LLC, Due 3/16/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			7.60%
Interest rate paid in cash			8.17%
Interest rate paid in kind			3.75%
Acquisition Date			Mar. 16, 2021
Maturity			Mar. 16, 2027
Principal			$ 4,528
Amortized Cost			4,461
Fair Value			$ 4,122
% of Net Assets			1.80%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Ascent Midco, L L C ( Revolver), Senior Secured Loans Due 2/5/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			5.75%
Interest Rate			10.14%
Acquisition Date			Feb. 05, 2020
Maturity			Feb. 05, 2025
Principal			$ 1,129
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Ascent Midco, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread Above Index			0%
Interest rate paid in kind		8%	8%
Acquisition Date		Feb. 05, 2020	Feb. 05, 2020
Principal		$ 0
Amortized Cost		2,032	$ 2,032
Fair Value		$ 1,914	$ 1,969	$ 1,418	2,554
% of Net Assets		0.90%	0.90%
Number of shares held				2,032,258
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held		2,032,258	2,032,258
Investment, Identifier [Axis]: Ascent Midco, L L C, Senior Secured Loans Due 2/5/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			5.75%
Interest Rate			10.14%
Acquisition Date			Feb. 05, 2020
Maturity			Feb. 05, 2025
Principal			$ 6,217
Amortized Cost			6,159
Fair Value			$ 6,217	$ 6,160	6,392
% of Net Assets			2.80%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jan. 04, 2019	Jan. 04, 2019
Amortized Cost		$ 297	$ 297
Fair Value		$ 418	$ 522
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		297,197	297,197
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Five, due 7/3/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.61%	6.25%
Interest Rate		11.93%	11.39%
Acquisition Date		Dec. 22, 2022	Dec. 22, 2022
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 399	$ 400
Amortized Cost		390	388
Fair Value		$ 394	$ 399
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Four, due 7/3/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Aug. 04, 2022	Aug. 04, 2022
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 790	$ 796
Amortized Cost		786	784
Fair Value		$ 779	$ 794
% of Net Assets		0.40%	0.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, One, due 7/3/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jan. 04, 2019	Jan. 04, 2019
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 1,905	$ 1,920
Amortized Cost		1,903	1,911
Fair Value		$ 1,878	$ 1,915
% of Net Assets		0.90%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Three, due 7/3/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jul. 01, 2021	Jul. 01, 2021
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 274	$ 276
Amortized Cost		270	272
Fair Value		$ 270	$ 275
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Two, due 7/3/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jun. 25, 2020	Jun. 25, 2020
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 464	$ 468
Amortized Cost		464	465
Fair Value		$ 458	$ 467
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, LLC (Revolver), Senior Secured Loans, due 7/3/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jan. 04, 2019	Jan. 04, 2019
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 320	$ 320
Amortized Cost		120
Fair Value		$ 118
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Avalara, Inc. (Revolver), Senior Secured Loans, due 10/19/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AvalaraInc.Member	mrcc:AvalaraInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember	mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%	7.25%
Interest Rate		12.64%	11.83%
Acquisition Date		Oct. 19, 2022	Oct. 19, 2022
Maturity		Oct. 19, 2028	Oct. 19, 2028
Principal		$ 400	$ 400
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Avalara, Inc. Senior Secured Loans, due 10/19/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AvalaraInc.Member	mrcc:AvalaraInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember	mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%	7.25%
Interest Rate		12.64%	11.83%
Acquisition Date		Oct. 19, 2022	Oct. 19, 2022
Maturity		Oct. 19, 2028	Oct. 19, 2028
Principal		$ 4,000	$ 4,000
Amortized Cost		3,912	3,902
Fair Value		$ 4,040	$ 3,900
% of Net Assets		2%	1.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Avison Young ( U S A) Inc., Senior Secured Loans, due 1/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BLSTOperatingCompanyLLCMember	mrcc:BLSTOperatingCompanyLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Retail	Retail
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 28, 2020	Aug. 28, 2020
Amortized Cost		$ 712	$ 712
Fair Value		$ 420	$ 420
% of Net Assets		0.20%	0.20%
Number of shares held		139,883
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held			139,883
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Senior Secured Loans, due 8/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BLSTOperatingCompanyLLCMember	mrcc:BLSTOperatingCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Retail
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		9.50%	8.50%
Interest Rate			12.62%
Interest rate paid in cash		5.44%
Interest rate paid in kind		12.94%
Acquisition Date		Aug. 28, 2020	Aug. 28, 2020
Maturity		Aug. 28, 2025	Aug. 28, 2025
Principal		$ 639	$ 588
Amortized Cost		402	351
Fair Value		$ 600	$ 571
% of Net Assets		0.30%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Bluesight, Inc (Revolver) Senior Secured Loans 7/17/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%
Interest Rate		12.57%
Acquisition Date		Jul. 17, 2023
Maturity		Jul. 17, 2029
Principal		$ 174
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bluesight, Inc Senior Secured Loans, 7/17/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%
Interest Rate		12.57%
Acquisition Date		Jul. 17, 2023
Maturity		Jul. 17, 2029
Principal		$ 2,000
Amortized Cost		1,941
Fair Value		$ 1,940
% of Net Assets		0.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Class B Common Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jul. 17, 2023
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Number of units held		11,087
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Preferred units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest rate paid in kind		9%
Acquisition Date		Jul. 17, 2023
Amortized Cost		$ 21
Fair Value		$ 21
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Number of units held		21
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Delayed Draw) , Senior Secured Loans, due 9/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			6.25%
Interest Rate			10.98%
Acquisition Date			Sep. 08, 2021
Maturity			Sep. 08, 2027
Principal			$ 1,906
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Revolver), Senior Secured Loans, due 9/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			6.25%
Interest Rate			10.98%
Acquisition Date			Sep. 08, 2021
Maturity			Sep. 08, 2027
Principal			$ 1,069
Amortized Cost			397
Fair Value			$ 389
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings), Senior Secured Loans, due 9/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			6.25%
Interest Rate			10.98%
Acquisition Date			Sep. 08, 2021
Maturity			Sep. 08, 2027
Principal			$ 13,195
Amortized Cost			13,042
Fair Value			$ 12,898
% of Net Assets			5.70%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Bonterra, LLC (Revolver), Senior Secured Loans, Due 9/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%
Interest Rate		12.64%
Acquisition Date		Sep. 08, 2021
Maturity		Sep. 08, 2027
Principal		$ 1,069
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, One, Due 9/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%
Interest Rate		12.64%
Acquisition Date		Sep. 08, 2021
Maturity		Sep. 08, 2027
Principal		$ 13,437
Amortized Cost		13,302
Fair Value		$ 13,135
% of Net Assets		6.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, Two, Due 9/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8%
Interest rate paid in kind		13.39%
Acquisition Date		Sep. 28, 2023
Maturity		Sep. 08, 2027
Principal		$ 1,902
Amortized Cost		1,874
Fair Value		$ 1,902
% of Net Assets		0.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Born To Run, L L C ( Delayed Draw) Senior Secured Loans, due 4/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			6%
Interest Rate			10.73%
Acquisition Date			Apr. 01, 2021
Maturity			Apr. 01, 2027
Principal			$ 470
Amortized Cost			470
Fair Value			$ 452
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Born To Run, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BornToRunLLCMember	mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Apr. 01, 2021	Apr. 01, 2021
Amortized Cost		$ 269	$ 269
Fair Value			$ 233
% of Net Assets		0%	0.10%
Number of shares held		269,438
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		false	true
Investment, Non-income Producing [true false]		false	true
Number of units held			269,438
Investment, Identifier [Axis]: Born To Run, L L C, Senior Secured Loans, due 4/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BornToRunLLCMember	mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.26%	6%
Interest Rate		11.63%	10.73%
Acquisition Date		Apr. 01, 2021	Apr. 01, 2021
Maturity		Apr. 01, 2027	Apr. 01, 2027
Principal		$ 3,430	$ 3,448
Amortized Cost		3,385	3,395
Fair Value		$ 2,662	$ 3,318
% of Net Assets		1.30%	1.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Born To Run, LLC, Senior Secured Loans, Two, Due 4/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.26%
Interest Rate		11.63%
Acquisition Date		Apr. 01, 2021
Maturity		Apr. 01, 2027
Principal		$ 467
Amortized Cost		467
Fair Value		$ 363
% of Net Assets		0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Brickell Bay Acquisition Corp, Senior Secured Loans, due 2/12/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BrickellBayAcquisitionCorpMember	mrcc:BrickellBayAcquisitionCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.65%	6.50%
Interest Rate		11.90%	10.24%
Acquisition Date		Feb. 12, 2021	Feb. 12, 2021
Maturity		Feb. 12, 2026	Feb. 12, 2026
Principal		$ 1,866	$ 1,880
Amortized Cost		1,840	1,850
Fair Value		$ 1,866	$ 1,847
% of Net Assets		0.90%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, One, due 11/5/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, Two, due 11/5/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Burroughs, Inc. ( Revolver), Senior Secured Loans, due 12/22/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.72%
Acquisition Date			Dec. 22, 2017
Maturity			Dec. 22, 2023
Principal			$ 1,215
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Burroughs, Inc. (Revolver), Senior Secured Loans, due 12/22/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%
Interest Rate		11.93%
Acquisition Date		Dec. 22, 2017
Maturity		Dec. 20, 2024
Principal		$ 1,215
Amortized Cost		1,020
Fair Value		$ 1,020
% of Net Assets		0.50%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, One, due 12/22/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%
Interest Rate		11.93%
Acquisition Date		Dec. 22, 2017
Maturity		Dec. 20, 2024
Principal		$ 4,976
Amortized Cost		4,976
Fair Value		$ 4,976
% of Net Assets		2.40%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, due 12/22/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest rate paid in kind			10.72%
Acquisition Date			Dec. 22, 2017
Maturity			Dec. 22, 2023
Principal			$ 5,201
Amortized Cost			5,201
Fair Value			$ 5,201
% of Net Assets			2.30%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, One, due 4/10/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, Two, due 4/10/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC) (Revolver), Senior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Fair Value					550
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Equity Securities, Common Stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Number of shares held		58,779		58,779
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, One
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, Two
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Senior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			May 02, 2017
Fair Value			$ 146	$ 146	4,561
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, One, due 12/17/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CgiAutomatedManufacturingLlcMember	mrcc:CgiAutomatedManufacturingLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.11%	6.50%
Interest Rate		12.43%	11.34%
Acquisition Date		Sep. 09, 2022	Sep. 09, 2022
Maturity		Dec. 17, 2026	Dec. 17, 2026
Principal		$ 3,900	$ 3,975
Amortized Cost		3,806	3,863
Fair Value		$ 3,846	$ 3,975
% of Net Assets		1.90%	1.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, Two, due 12/17/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:CgiAutomatedManufacturingLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.11%	6.50%
Interest Rate		12.43%	11.34%
Acquisition Date		Sep. 30, 2022	Sep. 30, 2022
Maturity		Dec. 17, 2026	Dec. 17, 2026
Principal		$ 1,119	$ 1,141
Amortized Cost		1,096	1,114
Fair Value		$ 1,104	$ 1,141
% of Net Assets		0.50%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Cadent, L L C ( Revolver), Senior Secured Loans, due 9/11/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Cadent, L L C, Senior Secured Loans, due 9/11/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Calabrio, Inc. ( Revolver), Senior Secured Loans, due 4/16/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CalabrioIncMember	mrcc:CalabrioIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.13%	7%
Interest Rate		12.45%	11.75%
Acquisition Date		Apr. 16, 2021	Apr. 16, 2021
Maturity		Apr. 16, 2027	Apr. 16, 2027
Principal		$ 409	$ 409
Amortized Cost		234	234
Fair Value		$ 234	$ 233
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Calabrio, Inc., Senior Secured Loans, due 4/16/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CalabrioIncMember	mrcc:CalabrioIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.13%	7%
Interest Rate		12.44%	11.73%
Acquisition Date		Apr. 16, 2021	Apr. 16, 2021
Maturity		Apr. 16, 2027	Apr. 16, 2027
Principal		$ 3,400	$ 3,400
Amortized Cost		3,343	3,334
Fair Value		$ 3,400	$ 3,379
% of Net Assets		1.60%	1.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: California Pizza Kitchen, Inc., Equity Securities, Common units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CaliforniaPizzaKitchenInc.Member
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Beverage, Food & Tobacco
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Aug. 19, 2016
Amortized Cost			$ 5,468
Fair Value			$ 1,266
% of Net Assets			0.60%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			true
Number of units held			78,699
Investment, Identifier [Axis]: Cano Health, L L C, Senior Secured Loans, due 11/23/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Caravel Autism Health LLC One Senior Secured Loans due 6/30/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.76%
Interest Rate		11.01%
Acquisition Date		Jun. 30, 2021
Maturity		Jun. 30, 2027
Principal		$ 1,396
Amortized Cost		1,396
Fair Value		$ 1,368
% of Net Assets		0.70%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Delayed Draw), Senior Secured Loans, due 6/30/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			8.75%
Interest rate paid in cash			8.97%
Interest rate paid in kind			3%
Acquisition Date			Jun. 30, 2021
Maturity			Jun. 30, 2027
Principal			$ 3,750
Amortized Cost			188
Fair Value			$ 173
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Revolver), Senior Secured Loans, due 6/30/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CaravelAutismHealthLLCMember	mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.76%	8.75%
Interest Rate		11.01%
Interest rate paid in kind			3%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2027	Jun. 30, 2027
Principal		$ 1,269	$ 1,260
Amortized Cost		494	1,135
Fair Value		$ 484	$ 1,048
% of Net Assets		0.20%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Caravel Autism Health, L L C, Senior Secured Loans, due 6/30/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CaravelAutismHealthLLCMember	mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.76%	8.75%
Interest Rate		11.01%
Interest rate paid in cash			8.97%
Interest rate paid in kind			3%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2027	Jun. 30, 2027
Principal		$ 5,024	$ 5,016
Amortized Cost		4,955	4,935
Fair Value		$ 4,923	$ 4,630
% of Net Assets		2.40%	2.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Cassavant Holdings, L L C, Unitranche Secured Loans, due 9/8/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CassavantHoldingsLLCMember	mrcc:CassavantHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Unitranche Secured Loans	Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Aerospace & Defense	Aerospace & Defense
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		8.36%	6.50%
Interest Rate		13.69%	10.62%
Acquisition Date		Sep. 08, 2021	Sep. 08, 2021
Maturity		Sep. 08, 2026	Sep. 08, 2026
Principal		$ 7,697	$ 7,580
Amortized Cost		7,601	7,461
Fair Value		$ 7,578	$ 7,436
% of Net Assets		3.60%	3.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Delayed Draw), Senior Secured Loans, due 4/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember	mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE Real Estate Sector [Member]	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.25%	8.25%
Interest Rate		13.58%	12.43%
Acquisition Date		May 03, 2022	May 03, 2022
Maturity		Apr. 30, 2025	Apr. 30, 2025
Principal		$ 285	$ 337
Amortized Cost		285	337
Fair Value		$ 286	$ 337
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Revolver), Senior Secured Loans, due 4/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember	mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE Real Estate Sector [Member]	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.25%	8.25%
Interest Rate		13.57%	12.43%
Acquisition Date		May 03, 2022	May 03, 2022
Maturity		Apr. 30, 2025	Apr. 30, 2025
Principal		$ 1,395	$ 1,653
Amortized Cost		870	720
Fair Value		$ 870	$ 719
% of Net Assets		0.40%	0.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C, Senior Secured Loans, due 4/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember	mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE Real Estate Sector [Member]	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.25%	8.25%
Interest Rate		13.58%	12.43%
Acquisition Date		May 03, 2022	May 03, 2022
Maturity		Apr. 30, 2025	Apr. 30, 2025
Principal		$ 2,784	$ 3,300
Amortized Cost		2,752	3,245
Fair Value		$ 2,798	$ 3,296
% of Net Assets		1.40%	1.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Chess.com, L L C ( Revolver), Senior Secured Loans, due 12/31/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Chess.comLLCMember	mrcc:Chess.comLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		11.99%	11.23%
Acquisition Date		Dec. 31, 2021	Dec. 31, 2021
Maturity		Dec. 31, 2027	Dec. 31, 2027
Principal		$ 652	$ 652
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Chess.com, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Chess.comLLCMember	mrcc:Chess.comLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 31, 2021	Dec. 31, 2021
Amortized Cost		$ 87	$ 87
Fair Value		$ 55	$ 50
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		2	2
Investment, Identifier [Axis]: Chess.com, L L C, Senior Secured Loans, due 12/31/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Chess.comLLCMember	mrcc:Chess.comLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		11.99%	11.23%
Acquisition Date		Dec. 31, 2021	Dec. 31, 2021
Maturity		Dec. 31, 2027	Dec. 31, 2027
Principal		$ 5,910	$ 5,955
Amortized Cost		5,821	5,852
Fair Value		$ 5,866	$ 5,866
% of Net Assets		2.80%	2.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Corel Inc., Senior Secured Loans, due 7/2/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Crownpeak Technology Inc. (Revolver) Senior Secured Loans, Due 2/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.35%	7.25%
Interest Rate		12.67%	11.47%
Acquisition Date		Feb. 28, 2019	Feb. 28, 2019
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 500	$ 500
Amortized Cost		67
Fair Value		$ 67
% of Net Assets		0%	0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Four, Due 2/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%	7.25%
Interest Rate		12.68%	11.41%
Acquisition Date		Sep. 27, 2022	Sep. 27, 2022
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 3,333	$ 3,333
Amortized Cost		3,333	3,333
Fair Value		$ 3,333	$ 3,333
% of Net Assets		1.60%	1.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans One, Due 2/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%	7.25%
Interest Rate		12.68%	11.47%
Acquisition Date		Feb. 28, 2019	Feb. 28, 2019
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 4,000	$ 4,000
Amortized Cost		3,993	3,979
Fair Value		$ 4,000	$ 4,000
% of Net Assets		1.90%	1.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Three, Due 2/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%	7.25%
Interest Rate		12.68%	11.47%
Acquisition Date		Feb. 28, 2019	Feb. 28, 2019
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 60	$ 60
Amortized Cost		60	60
Fair Value		$ 60	$ 60
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Two, Due 2/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%	7.25%
Interest Rate		12.37%	11.47%
Acquisition Date		Sep. 27, 2022	Sep. 27, 2022
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 1,273	$ 1,273
Amortized Cost		1,257	1,252
Fair Value		$ 1,273	$ 1,273
% of Net Assets		0.60%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Curion Holdings, L L C, Equity Securities, Common stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Curion Holdings, L L C [ Member]
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Aug. 17, 2018
% of Net Assets			0%
Number of shares held			58,779
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: D S Parent, Inc., Senior Secured Loans, due 12/8/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Destination Media, Inc. ( Revolver), Senior Secured Loans, due 4/7/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			5.50%
Interest Rate			9.94%
Acquisition Date			Apr. 07, 2017
Maturity			Apr. 07, 2023
Principal			$ 542
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Destination Media, Inc. (Delayed Draw), Senior Secured Loans, due 6/21/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.15%
Interest Rate		12.56%
Acquisition Date		Jun. 21, 2023
Maturity		Jun. 21, 2028
Principal		$ 500
Amortized Cost		29
Fair Value		$ 29
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Destination Media, Inc. (Revolver), Senior Secured Loans, due 6/21/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.15%
Interest Rate		12.56%
Acquisition Date		Jun. 21, 2023
Maturity		Jun. 21, 2028
Principal		$ 103
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 4/7/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			5.50%
Interest Rate			9.94%
Acquisition Date			Apr. 07, 2017
Maturity			Apr. 07, 2023
Principal			$ 377
Amortized Cost			377
Fair Value			$ 377
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 6/21/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%
Interest Rate		12.54%
Acquisition Date		Jun. 21, 2023
Maturity		Jun. 21, 2028
Principal		$ 998
Amortized Cost		964
Fair Value		$ 1,001
% of Net Assets		0.50%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, One, Class A-1 units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionIncMember	mrcc:DoradoAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Amortized Cost		$ 207	$ 207
Fair Value		$ 209	$ 215
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		189,922	189,922
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, Two, Class A-2 units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionIncMember	mrcc:DoradoAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Fair Value		$ 207	$ 224
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		189,922	189,922
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Delayed Draw) , Senior Secured Loans, due 6/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.72%
Acquisition Date			Jun. 30, 2021
Maturity			Jun. 30, 2026
Principal			$ 216
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Revolver) , Senior Secured Loans, due 6/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionInc.Member	mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		11.93%	10.92%
Interest rate paid in cash			8.08%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2026	Jun. 30, 2026
Principal		$ 596	$ 596
Amortized Cost			596
Fair Value			$ 596
% of Net Assets		0%	0.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, One, due 6/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionInc.Member	mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		11.93%	10.72%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2026	Jun. 30, 2026
Principal		$ 4,900	$ 4,938
Amortized Cost		4,840	4,862
Fair Value		$ 4,778	$ 4,928
% of Net Assets		2.30%	2.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, Two, Due 6/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionInc.Member	mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.65%	6.76%
Interest Rate		11.90%	11.34%
Acquisition Date		Nov. 27, 2022	Nov. 27, 2022
Maturity		Jun. 30, 2026	Jun. 30, 2026
Principal		$ 4,061	$ 4,082
Amortized Cost		3,980	3,980
Fair Value		$ 3,960	$ 4,074
% of Net Assets		1.90%	1.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Delayed Draw), Senior Secured Loans, due 9/1/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.39%
Interest rate paid in kind			11.56%
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Maturity		Sep. 01, 2028	Sep. 01, 2028
Principal		$ 874	$ 330
Amortized Cost		392	103
Fair Value		$ 389	$ 102
% of Net Assets		0.20%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Revolver), Senior Secured Loans, due 9/1/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.39%	11.56%
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Maturity		Sep. 01, 2028	Sep. 01, 2028
Principal		$ 522	$ 522
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Equity Securities, Class A Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Amortized Cost		$ 130	$ 130
Fair Value		$ 132	$ 126
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		130,433	130,433
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Senior Secured Loans, due 9/1/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.39%
Interest rate paid in kind			11.56%
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Maturity		Sep. 01, 2028	Sep. 01, 2028
Principal		$ 3,000	$ 3,000
Amortized Cost		2,947	2,943
Fair Value		$ 2,978	$ 2,971
% of Net Assets		1.40%	1.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, One, due 10/1/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, Two, due 10/1/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Drilling Info Holdings, Inc., Senior Secured Loans, due 7/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Education Corporation of America, Equity Securities, Series G Preferred Stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EducationCorporationofAmericaMember	mrcc:EducationCorporationofAmericaMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		12%	12%
Acquisition Date		Sep. 03, 2015	Sep. 03, 2015
Amortized Cost		$ 7,492	$ 7,492
% of Net Assets		0%	0%
Number of shares held		8,333	8,333
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Education Corporation of America, Junior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EducationCorporationofAmericaMember	mrcc:EducationCorporationofAmericaMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans	Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Spread Above Index		11%	11%
Interest rate paid in cash		14%	10.23%
Interest rate paid in kind		5.50%	5.50%
Acquisition Date		Sep. 03, 2015	Sep. 03, 2015
Principal		$ 833	$ 833
Amortized Cost		831	831
Fair Value		$ 2,085	$ 1,882
% of Net Assets		1%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		false	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Elevate Textiles, Inc. (fka International Textile Group, Inc.), Senior Secured Loans, due 9/30/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C ( Delayed Draw), Senior Secured Loans, due 4/14/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C, Senior Secured Loans, due 4/14/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc. ( Revolver), Senior Secured Loans, due 3/7/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, One, due 3/7/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, Two,due 3/7/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Equine Network, L L C, (Delayed Draw), Senior Secured Loans, due 12/31/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			10.24%
Acquisition Date			Dec. 31, 2020
Maturity			Dec. 31, 2025
Principal			$ 427
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Equine Network, L L C, (Revolver), Senior Secured Loans, due 12/31/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			10.30%
Acquisition Date			Dec. 31, 2020
Maturity			Dec. 31, 2025
Principal			$ 171
Amortized Cost			128
Fair Value			$ 127
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Equine Network, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EquineNetworkLLCMember	mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Hotels, Gaming & Leisure	Hotels, Gaming & Leisure
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Amortized Cost		$ 111	$ 111
Fair Value		$ 115	$ 109
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		108	108
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, One, due 12/31/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			10.24%
Acquisition Date			Dec. 31, 2020
Maturity			Dec. 31, 2025
Principal			$ 1,719
Amortized Cost			1,694
Fair Value			$ 1,709
% of Net Assets			0.70%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, Two, due 12/31/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			10.24%
Acquisition Date			Jan. 29, 2021
Maturity			Dec. 31, 2025
Principal			$ 780
Amortized Cost			769
Fair Value			$ 775
% of Net Assets			0.30%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc. ( Revolver), Senior Secured Loans, due 4/28/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc., Senior Secured Loans, due 4/27/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Express Wash Acquisition Company, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		8%	8%
Acquisition Date		Dec. 28, 2020	Dec. 28, 2020
Amortized Cost		$ 125	$ 125
Fair Value		$ 75	$ 118
% of Net Assets		0.10%	0.10%
Number of shares held		121,311
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held			121,311
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC (Revolver), Senior Secured Loans, due 7/14/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	10.83%
Acquisition Date		Jul. 14, 2022	Jul. 14, 2022
Maturity		Jul. 14, 2028	Jul. 14, 2028
Principal		$ 379	$ 379
Amortized Cost		209	209
Fair Value		$ 209	$ 208
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, One, Due 7/14/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Jul. 14, 2022	Jul. 14, 2022
Maturity		Jul. 14, 2028	Jul. 14, 2028
Principal		$ 7,067	$ 8,160
Amortized Cost		7,033	8,114
Fair Value		$ 7,067	$ 8,119
% of Net Assets		3.40%	3.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, Two, Due 7/14/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	10.43%
Acquisition Date		Jul. 14, 2022	Jul. 14, 2022
Maturity		Jul. 14, 2028	Jul. 14, 2028
Principal		$ 1,517	$ 1,528
Amortized Cost		1,517	1,528
Fair Value		$ 1,517	$ 1,521
% of Net Assets		0.70%	0.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Familia Dental Group Holdings, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Familia Dental Group Holdings, LLC	Familia Dental Group Holdings, LLC
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Apr. 08, 2016	Apr. 08, 2016
Principal		$ 0
Amortized Cost		4,152	$ 4,030
Fair Value		$ 2,351	$ 2,625	$ 2,508	1,919
% of Net Assets		1.20%	1.20%
Number of shares held		1,212
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		1,212	1,176	1,158
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Junior Secured Loans, due 6/28/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:FloridaEastCoastIndustriesLLCMember	mrcc:FloridaEastCoastIndustriesLLCMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans	Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		16%	16%
Acquisition Date		Aug. 09, 2021	Aug. 09, 2021
Maturity		Jun. 28, 2024	Jun. 28, 2024
Principal		$ 845	$ 1,778
Amortized Cost		837	1,753
Fair Value		$ 845	$ 1,784
% of Net Assets		0.40%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		false	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Senior Secured Loans, due 6/28/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FloridaEastCoastIndustriesLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			10.50%
Acquisition Date			Aug. 09, 2021
Maturity			Jun. 28, 2024
Principal			$ 617
Amortized Cost			606
Fair Value			$ 619
% of Net Assets			0.30%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Forman Mills, Inc, Equity Securities, Warrants
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FormanMillsInc.Member
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Jan. 14, 2020
Maturity			Jan. 14, 2029
Fair Value			$ 155
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			true
Warrants to Purchase Percentage of Equity			2.60%
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, One, due 4/30/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FormanMillsIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			9.50%
Interest rate paid in cash			11.94%
Interest rate paid in kind			2%
Acquisition Date			Jan. 14, 2020
Maturity			Apr. 30, 2024
Principal			$ 1,275
Amortized Cost			1,275
Fair Value			$ 1,253
% of Net Assets			0.60%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, Two, due 4/30/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FormanMillsIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			9.50%
Interest rate paid in cash			11.94%
Interest rate paid in kind			2%
Acquisition Date			Oct. 04, 2016
Maturity			Apr. 30, 2024
Principal			$ 6,909
Amortized Cost			6,909
Fair Value			$ 6,698
% of Net Assets			3%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Forman Mills, Inc., Senior Secured Loans, due 6/20/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:FormanMillsInc.Member
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Retail
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread Above Index		3.90%
Interest rate paid in kind		3.90%
Acquisition Date		Apr. 27, 2023
Maturity		Jun. 20, 2028
Principal		$ 1,308
Amortized Cost		1,308
Fair Value		$ 965
% of Net Assets		0.50%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: GC Champion Acquisition LLC (Delayed Draw), Senior Notes, Due 8/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.75%
Interest Rate			11.15%
Acquisition Date			Aug. 19, 2022
Maturity			Aug. 18, 2028
Principal			$ 704
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Due 8/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.75%
Interest Rate			11.15%
Acquisition Date			Aug. 19, 2022
Maturity			Aug. 18, 2028
Principal			$ 2,528
Amortized Cost			2,480
Fair Value			$ 2,503
% of Net Assets			1.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, One, Due 8/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.75%
Interest Rate		11.78%
Acquisition Date		Aug. 19, 2022
Maturity		Aug. 18, 2028
Principal		$ 2,535
Amortized Cost		2,492
Fair Value		$ 2,513
% of Net Assets		1.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Two, Due 8/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%
Interest Rate		11.28%
Acquisition Date		Aug. 19, 2022
Maturity		Aug. 18, 2028
Principal		$ 704
Amortized Cost		704
Fair Value		$ 698
% of Net Assets		0.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: GC Champion Acquisition Llc Senior Notes Three Due 8/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.50%
Interest Rate		11.87%
Acquisition Date		Aug. 01, 2023
Maturity		Aug. 18, 2028
Principal		$ 2,112
Amortized Cost		2,050
Fair Value		$ 2,112
% of Net Assets		1%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: H A H Group Holding Company L L C, Senior Secured Loans, due 10/29/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H A L O Buyer, Inc., Senior Secured Loans, due 6/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans , Two
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Spread Above Index		9.46%	12.50%
Interest rate paid in kind		17.96%	16.62%
Acquisition Date		Oct. 20, 2017	Oct. 20, 2017
Principal		$ 4,758	$ 4,758
Amortized Cost		4,758	4,758
Fair Value		$ 6,094	$ 5,805	$ 5,708	5,420
% of Net Assets		2.90%	2.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans, One
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Spread Above Index		9.46%	12.50%
Interest rate paid in kind		17.96%	16.62%
Acquisition Date		Oct. 20, 2017	Oct. 20, 2017
Principal		$ 13,242	$ 13,242
Amortized Cost		13,242	13,242
Fair Value		$ 16,962	$ 16,159	15,888	15,084
% of Net Assets		8.20%	7.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc. ( Revolver), Senior Secured Loans, due 7/9/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HS4AcquisitioncoIncMember	mrcc:HS4AcquisitioncoIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.85%	6.75%
Interest Rate		12.17%	11.14%
Acquisition Date		Jul. 09, 2019	Jul. 09, 2019
Maturity		Jul. 09, 2025	Jul. 09, 2025
Principal		$ 817	$ 817
Amortized Cost		531	409
Fair Value		$ 530	$ 407
% of Net Assets		0.30%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc., Senior Secured Loans, due 7/9/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HS4AcquisitioncoIncMember	mrcc:HS4AcquisitioncoIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.85%	6.75%
Interest Rate		12.17%	11.14%
Acquisition Date		Jul. 09, 2019	Jul. 09, 2019
Maturity		Jul. 09, 2025	Jul. 09, 2025
Principal		$ 9,824	$ 9,899
Amortized Cost		9,752	9,801
Fair Value		$ 9,804	$ 9,855
% of Net Assets		4.70%	4.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, One, due 12/13/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, Two, due 12/13/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Hastings Manufacturing Company (Revolver), Senior Secured Loans, Due 12/31/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.60%
Interest Rate		12.92%
Acquisition Date		Mar. 29, 2023
Maturity		Dec. 31, 2024
Principal		$ 691
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, One, Due 12/31/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.60%
Interest Rate		12.92%
Acquisition Date		Apr. 24, 2018
Maturity		Dec. 31, 2024
Principal		$ 1,858
Amortized Cost		1,857
Fair Value		$ 1,858
% of Net Assets		0.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, Two, Due 12/31/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]		us-gaap:SeniorSubordinatedLoansMember
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.60%
Interest Rate		12.92%
Acquisition Date		Mar. 29, 2023
Maturity		Dec. 31, 2024
Principal		$ 665
Amortized Cost		665
Fair Value		$ 665
% of Net Assets		0.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Hastings Manufacturing Company, Senior Secured Loans, due 4/24/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			7.25%
Interest Rate			11.64%
Acquisition Date			Apr. 24, 2018
Maturity			Apr. 24, 2023
Principal			$ 2,026
Amortized Cost			2,023
Fair Value			$ 2,026
% of Net Assets			0.90%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: I D I G Parent, L L C, Equity Securities, Common stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		I D I G Parent, L L C [ Member]	I D I G Parent, L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jan. 04, 2021	Jan. 04, 2021
Amortized Cost		$ 250	$ 248
Fair Value		$ 287	$ 324
% of Net Assets		0.20%	0.10%
Number of shares held			245,958
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		245,958
Investment, Identifier [Axis]: I N H Buyer, Inc., Senior Secured Loans, due 6/28/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:INHBuyerInc.Member	mrcc:INHBuyerInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest rate paid in cash		8.99%
Interest rate paid in kind		3.50%	3.50%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 28, 2028	Jun. 28, 2028
Principal		$ 3,006	$ 2,950
Amortized Cost		2,985	2,925
Fair Value		$ 2,925	$ 2,832
% of Net Assets		1.40%	1.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: In Mobi Pte, Ltd, Media: Equity Securities, due 9/18/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:InMobiPteLtdMember	mrcc:InMobiPteLtdMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		International	International
Acquisition Date		Sep. 18, 2015	Sep. 18, 2015
Maturity		Sep. 18, 2025	Sep. 18, 2025
Fair Value		$ 1,965	$ 1,816
% of Net Assets		1%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Warrants to Purchase Percentage of Equity		2.80%	2.80%
Investment, Identifier [Axis]: Independence Buyer, Inc, Senior Secured Loans, due 8/3/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IndependenceBuyerInc.Member	mrcc:IndependenceBuyerInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.90%	5.50%
Interest Rate		11.27%	9.74%
Acquisition Date		Aug. 03, 2021	Aug. 03, 2021
Maturity		Aug. 03, 2026	Aug. 03, 2026
Principal		$ 5,513	$ 5,940
Amortized Cost		5,446	5,849
Fair Value		$ 5,417	$ 5,866
% of Net Assets		2.60%	2.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Independence Buyer, Inc. ( Revolver), Senior Secured Loans, due 8/3/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IndependenceBuyerInc.Member	mrcc:IndependenceBuyerInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.90%	5.50%
Interest Rate		11.27%	9.74%
Acquisition Date		Aug. 03, 2021	Aug. 03, 2021
Maturity		Aug. 03, 2026	Aug. 03, 2026
Principal		$ 1,423	$ 1,423
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Independence Buyer, Inc., Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IndependenceBuyerInc.Member	mrcc:IndependenceBuyerInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 03, 2021	Aug. 03, 2021
Amortized Cost		$ 81	$ 81
Fair Value		$ 68	$ 102
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		81	81
Investment, Identifier [Axis]: Intermedia Holdings, Inc., Senior Secured Loans, due 7/21/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: J2 B W A Funding L L C, Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:J2BWAFundingLLCMember	mrcc:J2BWAFundingLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 24, 2020	Dec. 24, 2020
Fair Value		$ 27
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Percentage of profit sharing		0.70%	0.70%
Investment, Identifier [Axis]: J2 BWA Funding LLC (Delayed Draw), Senior Notes, Due 12/24/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:J2BWAFundingLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			9%
Acquisition Date			Dec. 24, 2020
Maturity			Dec. 24, 2026
Principal			$ 2,750
Amortized Cost			1,303
Fair Value			$ 1,298
% of Net Assets			0.60%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: J2 Bwa Funding Llc Revolver Senior Notes Due 12/24/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:J2BWAFundingLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest rate paid in kind		10%
Acquisition Date		Dec. 24, 2020
Maturity		Dec. 24, 2026
Principal		$ 2,750
Amortized Cost		1,570
Fair Value		$ 1,550
% of Net Assets		0.80%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: KL Moon Acquisition LLC Common Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Number of units held		0.1
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Revolver) Senior Secured Loans Due
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%
Interest Rate		12.37%
Acquisition Date		Feb. 01, 2023
Maturity		Feb. 01, 2029
Principal		$ 813
Amortized Cost		244
Fair Value		$ 244
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) Senior Secured Loans Due 2/1/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%
Interest Rate		12.37%
Acquisition Date		Feb. 01, 2023
Maturity		Feb. 01, 2029
Principal		$ 4,988
Amortized Cost		4,852
Fair Value		$ 4,988
% of Net Assets		2.40%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: KL Moon Acquisition, LLC (fka Spectrum Science Communications, LLC), Equity Securities, Common Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jan. 31, 2023
Amortized Cost		$ 491
Fair Value		$ 500
% of Net Assets		0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Identifier [Axis]: Kar Wash Holdings LLC Equity Securities Series A Preferred Stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jun. 27, 2023
Amortized Cost		$ 11
Fair Value		$ 11
% of Net Assets		0%
Number of shares held		8,619
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 2/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6%
Interest Rate		12.04%	10.77%
Acquisition Date		Aug. 03, 2022	Aug. 03, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 2,653	$ 2,667
Amortized Cost		2,234	1,790
Fair Value		$ 2,229	$ 1,782
% of Net Assets		1.10%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Revolver), Senior Secured Loans, due 2/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6%
Interest Rate		12.04%	10.77%
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 571	$ 572
Amortized Cost			305
Fair Value			$ 303
% of Net Assets		0%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kar Wash Holdings, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Amortized Cost		$ 103	$ 103
Fair Value		$ 61	$ 111
% of Net Assets		0%	0%
Number of shares held		99,807
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held			99,807
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, One, due 2/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6%
Interest Rate		12.01%	9.82%
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 1,580	$ 1,592
Amortized Cost		1,556	1,565
Fair Value		$ 1,576	$ 1,585
% of Net Assets		0.80%	0.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, Two, due 2/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6%
Interest Rate		12.01%	10.35%
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 1,132	$ 1,140
Amortized Cost		1,132	1,140
Fair Value		$ 1,129	$ 1,135
% of Net Assets		0.50%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Keystone Purchaser, L L C, Senior Secured Loans, due 5/7/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, One, Due 12/11/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.65%
Interest Rate			11.12%
Acquisition Date			Dec. 09, 2022
Maturity			Dec. 11, 2028
Principal			$ 720
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, Two, Due 12/11/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember	mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.15%	6.65%
Interest Rate		11.48%	11.12%
Acquisition Date		Dec. 09, 2022	Dec. 09, 2022
Maturity		Dec. 11, 2028	Dec. 11, 2028
Principal		$ 600	$ 600
Amortized Cost		132
Fair Value		$ 131
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Revolver), Senior Secured Loans, Due 12/11/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember	mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.15%	6.65%
Interest Rate		11.48%	11.12%
Acquisition Date		Dec. 09, 2022	Dec. 09, 2022
Maturity		Dec. 11, 2028	Dec. 11, 2028
Principal		$ 240	$ 240
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, , Senior Secured Loans, Due 12/11/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.65%
Interest Rate			11.12%
Acquisition Date			Dec. 09, 2022
Maturity			Dec. 11, 2028
Principal			$ 600
Amortized Cost			588
Fair Value			$ 588
% of Net Assets			0.30%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, One Due 12/11/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.15%
Interest Rate		11.40%
Acquisition Date		Dec. 09, 2022
Maturity		Dec. 11, 2028
Principal		$ 597
Amortized Cost		586
Fair Value		$ 591
% of Net Assets		0.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, Two, Due 12/11/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.15%
Interest Rate		11.40%
Acquisition Date		Dec. 09, 2022
Maturity		Dec. 11, 2028
Principal		$ 192
Amortized Cost		192
Fair Value		$ 190
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Kl Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Delayed Draw) Senior Secured Loans Due
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%
Interest Rate		12.37%
Acquisition Date		Feb. 01, 2023
Maturity		Feb. 01, 2029
Principal		$ 1,702
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: L S C S Holdings, Inc., Senior Secured Loans, due 12/15/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: L V F Holdings, Inc. ( Revolver), Senior Secured Loans, due 6/10/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LXJTIntermediateHoldingsIncMember	mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.15%	6.25%
Interest Rate		11.54%	10.98%
Acquisition Date		Jun. 10, 2021	Jun. 10, 2021
Maturity		Jun. 10, 2027	Jun. 10, 2027
Principal		$ 238	$ 238
Amortized Cost			157
Fair Value			$ 152
% of Net Assets		0%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, ( Delayed Draw) due 6/10/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			6.25%
Interest Rate			8.45%
Acquisition Date			Jun. 10, 2021
Maturity			Jun. 10, 2027
Principal			$ 344
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, One, due 6/10/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LVFHoldingsIncMember	mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.15%	6.25%
Interest Rate		11.54%	8.45%
Acquisition Date		Jun. 10, 2021	Jun. 10, 2021
Maturity		Jun. 10, 2027	Jun. 10, 2027
Principal		$ 1,470	$ 1,481
Amortized Cost		1,450	1,458
Fair Value		$ 1,433	$ 1,437
% of Net Assets		0.70%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, Two, due 6/10/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LVFHoldingsIncMember	mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.15%	6.25%
Interest Rate		11.54%	8.45%
Acquisition Date		Jun. 10, 2021	Jun. 10, 2021
Maturity		Jun. 10, 2027	Jun. 10, 2027
Principal		$ 1,407	$ 1,418
Amortized Cost		1,407	1,418
Fair Value		$ 1,372	$ 1,375
% of Net Assets		0.60%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc. ( Revolver), Senior Secured Loans, due 3/11/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LXJTIntermediateHoldingsIncMember	mrcc:LXJTIntermediateHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Mar. 11, 2020	Mar. 11, 2020
Maturity		Mar. 11, 2025	Mar. 11, 2025
Principal		$ 833	$ 833
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc., Senior Secured Loans, due 3/11/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LXJTIntermediateHoldingsIncMember	mrcc:LXJTIntermediateHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Mar. 11, 2020	Mar. 11, 2020
Maturity		Mar. 11, 2025	Mar. 11, 2025
Principal		$ 5,393	$ 5,468
Amortized Cost		5,356	5,413
Fair Value		$ 5,366	$ 5,394
% of Net Assets		2.60%	2.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Laseraway Intermediate Holdings I I, L L C, Senior Secured Loans, due 10/14/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 8/2/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			5.75%
Interest Rate			9.49%
Acquisition Date			Aug. 02, 2021
Maturity			Aug. 02, 2027
Principal			$ 1,400
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Revolver), Senior Secured Loans, due 8/2/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftedTrucksHoldingsLLCMember	mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		5.75%	5.75%
Interest Rate		11.14%	9.49%
Acquisition Date		Aug. 02, 2021	Aug. 02, 2021
Maturity		Aug. 02, 2027	Aug. 02, 2027
Principal		$ 1,667	$ 1,667
Amortized Cost		556
Fair Value		$ 544
% of Net Assets		0.30%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftedTrucksHoldingsLLCMember	mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 02, 2021	Aug. 02, 2021
Amortized Cost		$ 111	$ 111
Fair Value		$ 74	$ 78
% of Net Assets		0%	0%
Number of shares held		111,111
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		false	true
Investment, Non-income Producing [true false]		false	true
Number of units held			111,111
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Senior Secured Loans, due 8/2/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftedTrucksHoldingsLLCMember	mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		5.85%	5.75%
Interest Rate		11.10%	9.49%
Acquisition Date		Aug. 02, 2021	Aug. 02, 2021
Maturity		Aug. 02, 2027	Aug. 02, 2027
Principal		$ 6,878	$ 6,930
Amortized Cost		6,782	6,816
Fair Value		$ 6,740	$ 6,840
% of Net Assets		3.20%	3.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Liftforward SPV II LLC Senior Secured Loans Due 9/29/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftforwardSPVIILLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Interest rate paid in kind		16.18%
Acquisition Date		Nov. 10, 2016
Maturity		Mar. 31, 2024
Principal		$ 243
Amortized Cost		243
Fair Value		$ 223
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Liftforward SPV II, LLC, Senior Secured Loans, due 3/31/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftforwardSPVIILLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			10.75%
Interest Rate			15.14%
Acquisition Date			Nov. 10, 2016
Maturity			Mar. 31, 2023
Principal			$ 413
Amortized Cost			413
Fair Value			$ 403
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Lightbox Intermediate, L. P., Senior Secured Loans, due 5/11/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Luxury Optical Holdings Co., Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LuxuryOpticalHoldingsCo.Member
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Sep. 12, 2014
Fair Value			$ 209
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C ( Delayed Draw), Senior Secured Loans Due 1/26/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		15%	15%
Interest rate paid in kind		20.25%	18.74%
Acquisition Date		Apr. 26, 2021	Apr. 26, 2021
Maturity		Jan. 26, 2024	Jan. 26, 2024
Principal		$ 2,903	$ 1,793
Amortized Cost		2,903	1,000
Fair Value		$ 2,903	$ 1,000	957	850
% of Net Assets		1.40%	0.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securites
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 11, 2019	Jun. 11, 2019
Principal		$ 0
Amortized Cost		793	$ 793
Fair Value		$ 1,232	$ 1,291
% of Net Assets		0.60%	0.60%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	false
Percentage of units held		15.90%
Percentage of interests			15.90%
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Fair Value		$ 1,232	$ 1,291	$ 751	644
Percentage of interests		15.90%		15.90%
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Senior Secured Loans Due 1/26/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:HFZCapitalGroupLLCMember	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		London Interbank Offered Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		15%	15%
Interest rate paid in kind		20.53%	18.74%
Acquisition Date		Jan. 26, 2021	Jan. 26, 2021
Maturity		Jan. 26, 2024	Jan. 26, 2024
Principal		$ 9,732	$ 8,421
Amortized Cost		9,732	8,421
Fair Value		$ 9,732	$ 8,421	$ 8,057	7,154
% of Net Assets		4.70%	3.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C ( Revolver), Senior Secured Loans, due 11/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Feb. 28, 2020	Feb. 28, 2020
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 1,784	$ 1,784
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C , Equity Securities, Class A-2 units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Feb. 28, 2020	Feb. 28, 2020
Amortized Cost		$ 119	$ 119
Fair Value		$ 432	$ 204
% of Net Assets		0.20%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		118,906	118,906
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, One, due 11/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Dec. 29, 2021	Feb. 28, 2020
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 968	$ 9,722
Amortized Cost		968	9,615
Fair Value		$ 973	$ 9,736
% of Net Assets		0.50%	4.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, Two, due 11/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Dec. 29, 2021	Dec. 29, 2021
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 2,943	$ 2,972
Amortized Cost		2,908	2,926
Fair Value		$ 2,957	$ 2,977
% of Net Assets		1.40%	1.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M R C C Senior Loan Fund I, L L C, Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Controlled affiliate company investments	Controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		MRCC Senior Loan Fund I, LLC	MRCC Senior Loan Fund I, LLC
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		mrcc:InvestmentFundsVehiclesMember	mrcc:InvestmentFundsVehiclesMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 31, 2017	Oct. 31, 2017
Principal		$ 0
Amortized Cost		42,650	$ 42,650
Fair Value		$ 33,269	$ 35,509	36,544	41,125
% of Net Assets		16%	15.80%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Percentage of interests		50%	50%
Investment, Identifier [Axis]: M V Receivables I I, L L C ( Delayed Draw), Senior Secured Loans, due 7/29/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Banking
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			9.75%
Interest Rate			13.87%
Acquisition Date			Jul. 29, 2021
Maturity			Jul. 29, 2026
Principal			$ 8,115
Amortized Cost			7,752
Fair Value			$ 7,968
% of Net Assets			3.60%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Common units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MVReceivablesIILLCMember	mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jul. 29, 2021	Jul. 29, 2021
Amortized Cost		$ 600	$ 600
Fair Value			$ 1,154
% of Net Assets		0%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Warrants to Purchase Percentage of Equity			0.80%
Number of units held		1,458	1,458
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Due 7/28/2031, Warrants
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MVReceivablesIILLCMember	mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jul. 28, 2021	Jul. 28, 2021
Maturity		Jul. 28, 2031	Jul. 28, 2031
Amortized Cost		$ 363	$ 363
Fair Value			$ 1,655
% of Net Assets		0%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Warrants to Purchase Percentage of Equity		0.80%
Investment, Identifier [Axis]: M V Receivables I I, L L C, Senior Secured Loans, due 7/29/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		9.75%
Interest Rate		15.08%
Acquisition Date		Jul. 29, 2021
Maturity		Jul. 29, 2026
Principal		$ 8,100
Amortized Cost		7,737
Fair Value		$ 8,017
% of Net Assets		3.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: MC Asset Management (Corporate), LLC, Senior Secured Loans, Two, Due 1/26/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCAssetManagementCorporateLLCMember
Fair Value		$ 2,903	$ 1,000
Investment, Identifier [Axis]: MCP Shaw Acquisitionco, LLC, Senior Secured Loans, Three, due 11/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Feb. 28, 2020	Dec. 29, 2021
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 9,624	$ 978
Amortized Cost		9,545	978
Fair Value		$ 9,624	$ 979
% of Net Assets		4.60%	0.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: MEI Buyer LLC (Delayed Draw), Senior Secured Loans, due 6/29/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.50%
Interest Rate		11.82%
Acquisition Date		Jun. 30, 2023
Maturity		Jun. 29, 2029
Principal		$ 317
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: MEI Buyer LLC (Revolver), Senior Secured Loans, due 6/29/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.50%
Interest Rate		11.82%
Acquisition Date		Jun. 30, 2023
Maturity		Jun. 29, 2029
Principal		$ 410
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: MEI Buyer LLC, Equity Securities, Common Stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jun. 30, 2023
Amortized Cost		$ 155
Fair Value		$ 138
% of Net Assets		0.10%
Number of shares held		155
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: MEI Buyer LLC, Senior Secured Loans, due 6/29/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.50%
Interest Rate		11.82%
Acquisition Date		Jun. 30, 2023
Maturity		Jun. 29, 2029
Principal		$ 2,000
Amortized Cost		1,941
Fair Value		$ 2,015
% of Net Assets		1%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Delayed Draw), Senior Secured Loans, due 1/7/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Revolver), Senior Secured Loans, due 1/7/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C, Senior Secured Loans, due 1/7/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mammoth Holdings, LLC (Revolver), Senior Secured Loans, Due, 10/16/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MammothHoldingsLLCMember	mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6%
Interest Rate		12.01%	9.82%
Acquisition Date		Oct. 16, 2018	Oct. 16, 2018
Maturity		Oct. 16, 2024	Oct. 16, 2024
Principal		$ 657	$ 657
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Due 10/16/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%
Interest Rate		12.01%
Acquisition Date		Jan. 25, 2023
Maturity		Oct. 16, 2024
Principal		$ 13,770
Amortized Cost		13,765
Fair Value		$ 13,728
% of Net Assets		6.60%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Four, due 10/16/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			9.82%
Acquisition Date			Jun. 15, 2021
Maturity			Oct. 16, 2024
Principal			$ 1,633
Amortized Cost			1,633
Fair Value			$ 1,630
% of Net Assets			0.70%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, One, due 10/16/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			9.82%
Acquisition Date			Oct. 16, 2018
Maturity			Oct. 16, 2024
Principal			$ 1,920
Amortized Cost			1,911
Fair Value			$ 1,917
% of Net Assets			0.90%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Three, due 10/16/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			9.82%
Acquisition Date			Mar. 12, 2021
Maturity			Oct. 16, 2024
Principal			$ 6,291
Amortized Cost			6,291
Fair Value			$ 6,282
% of Net Assets			2.80%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Two, due 10/16/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			9.82%
Acquisition Date			Oct. 16, 2018
Maturity			Oct. 16, 2024
Principal			$ 4,031
Amortized Cost			4,031
Fair Value			$ 4,025
% of Net Assets			1.80%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation ( Revolver), Senior Secured Loans, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.85%
Acquisition Date			Oct. 20, 2020
Maturity			Oct. 20, 2025
Principal			$ 269
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Four, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.85%
Acquisition Date			Nov. 23, 2021
Maturity			Oct. 20, 2025
Principal			$ 214
Amortized Cost			214
Fair Value			$ 213
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, One, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.85%
Acquisition Date			Oct. 20, 2020
Maturity			Oct. 20, 2025
Principal			$ 3,430
Amortized Cost			3,377
Fair Value			$ 3,414
% of Net Assets			1.50%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Three, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.85%
Acquisition Date			May 10, 2022
Maturity			Oct. 20, 2025
Principal			$ 2,669
Amortized Cost			2,623
Fair Value			$ 2,656
% of Net Assets			1.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Two, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.85%
Acquisition Date			Nov. 23, 2021
Maturity			Oct. 20, 2025
Principal			$ 320
Amortized Cost			315
Fair Value			$ 318
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: MarkLogic Corporation, Equity Securities, Class A Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Oct. 20, 2020
Fair Value			$ 426
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			true
Number of units held			290,239
Investment, Identifier [Axis]: Mavenir Systems, Inc., Senior Secured Loans, due 8/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mc Kissock Investment Holdings, L L C, Senior Secured Loans, due 3/9/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Medallia, Inc, Senior Secured Loans, due 10/27/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MedalliaIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.10%	6.50%
Interest rate paid in kind		11.42%	10.88%
Acquisition Date		Aug. 15, 2022	Aug. 15, 2022
Maturity		Oct. 27, 2028	Oct. 27, 2028
Principal		$ 2,140	$ 2,049
Amortized Cost		2,106	2,011
Fair Value		$ 2,150	$ 2,041
% of Net Assets		1%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mindbody, Inc. ( Revolver) (f), Senior Secured Loans, due 2/14/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MindbodyIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.15%	7%
Interest Rate			11.73%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Feb. 14, 2025	Feb. 14, 2025
Principal		$ 667	$ 667
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, One, due 2/14/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MindbodyIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.15%	7%
Interest Rate		12.52%	11.73%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Feb. 14, 2025	Feb. 14, 2025
Principal		$ 6,536	$ 6,536
Amortized Cost		6,502	6,485
Fair Value		$ 6,526	$ 6,526
% of Net Assets		3.10%	2.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, Two, due 2/14/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MindbodyIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.15%	7%
Interest Rate		12.52%	11.73%
Acquisition Date		Sep. 22, 2021	Sep. 22, 2021
Maturity		Feb. 14, 2025	Feb. 14, 2025
Principal		$ 474	$ 674
Amortized Cost		474	674
Fair Value		$ 473	$ 673
% of Net Assets		0.20%	0.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Minotaur Acquisition, Inc., Senior Secured Loans, due 3/27/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, One 12/30/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.26%
Interest rate paid in cash		8.65%
Interest rate paid in kind		5%
Acquisition Date		Nov. 02, 2018
Maturity		Dec. 30, 2024
Principal		$ 6,059
Amortized Cost		6,057
Fair Value		$ 6,059
% of Net Assets		2.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, Two 12/30/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.26%
Interest rate paid in kind		5%
Acquisition Date		Jul. 27, 2023
Maturity		Dec. 30, 2024
Principal		$ 53
Amortized Cost		53
Fair Value		$ 53
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mnine Holdings, Inc (Revolver), Senior Secured Loans, Due 12/30/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.26%
Interest Rate		12.65%
Interest rate paid in cash		8.62%
Acquisition Date		Aug. 09, 2022
Maturity		Dec. 30, 2024
Principal		$ 533
Amortized Cost		533
Fair Value		$ 533
% of Net Assets		0.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mnine Holdings, Inc, Senior Secured Loans, Due 12/30/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			8%
Interest rate paid in cash			7.84%
Interest rate paid in kind			5%
Acquisition Date			Nov. 02, 2018
Maturity			Dec. 30, 2023
Principal			$ 5,492
Amortized Cost			5,477
Fair Value			$ 5,492
% of Net Assets			2.40%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mnine Holdings, Inc. (Revolver), Senior Secured Loans, due 12/30/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			8%
Interest rate paid in cash			7.84%
Interest rate paid in kind			5%
Acquisition Date			Aug. 09, 2022
Maturity			Dec. 30, 2023
Principal			$ 533
Amortized Cost			214
Fair Value		$ 533	$ 214	$ 240
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mnine Holdings, Inc., Equity Securities, Class B units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 30, 2020	Jun. 30, 2020
Principal		$ 0
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		6,400	6,400	6,400
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due 12/30/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Fair Value		$ 53		$ 6,001	5,771
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due Two 12/30/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Fair Value		$ 6,059	$ 5,492
Investment, Identifier [Axis]: Money Lion, Inc. ( Delayed Draw), Junior Secured Loans, due 3/24/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]			Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Banking
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			9.25%
Interest Rate			14.07%
Acquisition Date			Mar. 25, 2022
Maturity			Mar. 24, 2026
Principal			$ 1,500
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 10/16/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember
Spread Above Index		5.75%
Interest Rate		14.25%
Acquisition Date		Aug. 27, 2021
Maturity		Oct. 16, 2023
Principal		$ 375
Amortized Cost		373
Fair Value		$ 379
% of Net Assets		0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 3/24/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MoneyLionIncMember	mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans	Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		9.51%	9.25%
Interest Rate		14.90%	14.07%
Acquisition Date		Mar. 25, 2022	Mar. 25, 2022
Maturity		Mar. 24, 2026	Mar. 24, 2026
Principal		$ 5,250	$ 5,250
Amortized Cost		5,210	5,203
Fair Value		$ 5,275	$ 5,165
% of Net Assets		2.50%	2.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		false	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 5/1/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]			Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Banking
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			us-gaap:PrimeRateMember
Spread Above Index			5.75%
Interest Rate			13.25%
Acquisition Date			Aug. 27, 2021
Maturity			May 01, 2023
Principal			$ 1,500
Amortized Cost			1,490
Fair Value			$ 1,498
% of Net Assets			0.60%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: N C B P Property, L L C, Senior Secured Loans, due 12/16/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NCBPPropertyLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			9.50%
Interest Rate			13.62%
Acquisition Date			Dec. 18, 2020
Maturity			Jun. 16, 2023
Principal			$ 1,950
Amortized Cost			1,945
Fair Value			$ 1,955
% of Net Assets			0.90%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: N E C B Collections, L L C ( Revolver), Senior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		London Interbank Offered Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		11%	11%
Interest rate paid in kind		16.94%	14.61%
Acquisition Date		Jun. 25, 2019	Jun. 25, 2019
Principal		$ 1,356	$ 1,356
Amortized Cost		1,312	1,312
Fair Value		$ 424	$ 382	$ 426	632
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: N E C B Collections, L L C, Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 21, 2019	Jun. 21, 2019
Principal		$ 0
Amortized Cost		$ 1,458	$ 1,458
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Percentage of units held		20.80%	20.80%	20.80%
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Delayed Draw), Senior Secured Loans, Due 10/4/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.65%	6%
Interest Rate		11.04%	10.59%
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Maturity		Oct. 04, 2028	Oct. 04, 2028
Principal		$ 778	$ 778
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Revolver), Senior Secured Loans, Due 10/4/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6%
Interest Rate			10.59%
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Maturity		Oct. 04, 2028	Oct. 04, 2028
Principal		$ 438	$ 438
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Equity Securities, Common Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Amortized Cost		$ 327	$ 327
Fair Value		$ 370	$ 327
% of Net Assets		0.20%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]			true
Number of units held		327,133	327,133
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Senior Secured Loans, Due 10/4/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.65%	6%
Interest Rate		11.04%	10.59%
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Maturity		Oct. 04, 2028	Oct. 04, 2028
Principal		$ 3,474	$ 3,500
Amortized Cost		3,413	3,432
Fair Value		$ 3,508	$ 3,430
% of Net Assets		1.70%	1.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, One, Due 8/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.43%	11.22%
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 3,930	$ 3,960
Amortized Cost		3,880	3,898
Fair Value		$ 3,962	$ 4,039
% of Net Assets		1.90%	1.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, Two, Due 8/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.43%	11.22%
Acquisition Date		Aug. 26, 2022	Aug. 26, 2022
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 4,684	$ 4,719
Amortized Cost		4,683	4,719
Fair Value		$ 4,721	$ 4,813
% of Net Assets		2.30%	2.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits LLC Delayed Draw, Senior Secured Loans Due 8/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.43%	11.22%
Acquisition Date		Aug. 26, 2022	Aug. 26, 2022
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 5,078	$ 5,089
Amortized Cost		5,077	942
Fair Value		$ 5,119	$ 961
% of Net Assets		2.50%	0.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits, L L C (Revolver), Senior Secured Loans, Due 8/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.43%	11.42%
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 2,222	$ 2,222
Amortized Cost		889	889
Fair Value		$ 889	$ 889
% of Net Assets		0.40%	0.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, One, Series B units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		5%	5%
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Amortized Cost		$ 781	$ 781
Fair Value		$ 730	$ 934
% of Net Assets		0.40%	0.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held		116,460	116,460
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, Two, common units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Amortized Cost		$ 153	$ 153
Fair Value			$ 66
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		106,667	106,667
Investment, Identifier [Axis]: Natus Medical Incorporated, Senior Secured Loans, due 7/20/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Nearly Natural Inc. Senior Secured Loans One due 3/29/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		11.50%
Interest rate paid in cash		12.89%
Acquisition Date		Dec. 15, 2017
Maturity		Mar. 29, 2024
Principal		$ 6,545
Amortized Cost		6,544
Fair Value		$ 6,134
% of Net Assets		2.90%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Four, due 3/29/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		11.50%
Interest rate paid in cash		12.89%
Interest rate paid in kind		4%
Acquisition Date		Aug. 28, 2019
Maturity		Mar. 29, 2024
Principal		$ 1,847
Amortized Cost		1,847
Fair Value		$ 1,731
% of Net Assets		0.80%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Three, due 3/29/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		11.50%
Interest rate paid in cash		12.89%
Acquisition Date		Feb. 16, 2021
Maturity		Mar. 29, 2024
Principal		$ 3,084
Amortized Cost		3,084
Fair Value		$ 2,890
% of Net Assets		1.40%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Two, due 3/29/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		11.50%
Interest rate paid in cash		12.89%
Interest rate paid in kind		4%
Acquisition Date		Sep. 22, 2020
Maturity		Mar. 29, 2024
Principal		$ 1,696
Amortized Cost		1,696
Fair Value		$ 1,589
% of Net Assets		0.80%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, One, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalIncMember	mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Wholesale	Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 15, 2017	Dec. 15, 2017
Amortized Cost		$ 153	$ 153
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		152,174	152,174
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, Two, Class A A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalIncMember	mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Wholesale	Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 27, 2021	Aug. 27, 2021
Amortized Cost		$ 61	$ 61
Fair Value		$ 2
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		61,087	61,087
Investment, Identifier [Axis]: Nearly Natural, Inc. (Revolver), Senior Secured Loans, due 3/29/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		11.50%
Interest rate paid in cash		12.89%
Acquisition Date		Dec. 15, 2017
Maturity		Mar. 29, 2024
Principal		$ 2,608
Amortized Cost		2,608
Fair Value		$ 2,444
% of Net Assets		1.20%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural, Inc.( Revolver), Senior Secured loans, due 12/15/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			11.50%
Interest rate paid in cash			12.32%
Interest rate paid in kind			4%
Acquisition Date			Dec. 15, 2017
Maturity			Mar. 31, 2024
Principal			$ 2,505
Amortized Cost			2,505
Fair Value			$ 2,241
% of Net Assets			1%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Four, due 12/15/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			11.50%
Interest rate paid in cash			12.32%
Interest rate paid in kind			4%
Acquisition Date			Aug. 28, 2019
Maturity			Mar. 31, 2024
Principal			$ 1,868
Amortized Cost			1,868
Fair Value			$ 1,672
% of Net Assets			0.80%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, One, due 12/15/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			11.50%
Interest rate paid in cash			12.32%
Interest rate paid in kind		4%	4%
Acquisition Date			Dec. 15, 2017
Maturity			Mar. 31, 2024
Principal			$ 6,628
Amortized Cost			6,628
Fair Value			$ 5,931
% of Net Assets			2.60%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Three, due 12/15/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			11.50%
Interest rate paid in cash			12.32%
Interest rate paid in kind		4%	4%
Acquisition Date			Feb. 16, 2021
Maturity			Mar. 31, 2024
Principal			$ 3,115
Amortized Cost			3,115
Fair Value			$ 2,787
% of Net Assets			1.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Two, due 12/15/2022
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			11.50%
Interest rate paid in cash			12.32%
Interest rate paid in kind		4%	4%
Acquisition Date			Sep. 22, 2020
Maturity			Mar. 31, 2024
Principal			$ 1,714
Amortized Cost			1,714
Fair Value			$ 1,534
% of Net Assets			0.70%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Newforma, Inc. ( Revolver) (f), Senior Secured Loans, due 3/31/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			5.50%
Interest Rate			10.23%
Acquisition Date			Jun. 30, 2017
Maturity			Mar. 31, 2023
Principal			$ 1,250
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Newforma, Inc., Senior Secured Loans, due 3/31/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			5.50%
Interest Rate			10.23%
Acquisition Date			Jun. 30, 2017
Maturity			Mar. 31, 2023
Principal			$ 938
Amortized Cost			937
Fair Value			$ 938
% of Net Assets			0.40%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: North Haven Spartan U S Holdco, L L C, Senior Secured Loans, due 6/6/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Delayed Draw), Senior Secured Loans, due, 10/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%	6.50%
Interest Rate		11.44%	11.18%
Acquisition Date		Jul. 29, 2022	Jul. 29, 2022
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 1,056	$ 1,056
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Revolver), Senior Secured Loans, due, 10/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		12%	11.13%
Acquisition Date		Oct. 30, 2020	Oct. 30, 2020
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 416	$ 416
Amortized Cost		416	187
Fair Value		$ 409	$ 187
% of Net Assets		0.20%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, One, 10/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		11.99%	11.18%
Acquisition Date		Oct. 30, 2020	Oct. 30, 2020
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 2,431	$ 2,450
Amortized Cost		2,408	2,419
Fair Value		$ 2,390	$ 2,448
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, Two, 10/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%	6.25%
Interest Rate		11.44%	10.41%
Acquisition Date		Jul. 29, 2022	Jul. 29, 2022
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 2,572	$ 2,592
Amortized Cost		2,546	2,556
Fair Value		$ 2,518	$ 2,575
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Four, due 10/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		11.99%	11.18%
Acquisition Date		Sep. 03, 2021	Sep. 03, 2021
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 1,423	$ 1,434
Amortized Cost		1,423	1,434
Fair Value		$ 1,399	$ 1,433
% of Net Assets		0.70%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Three, due 10/30/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.60%	6.50%
Interest Rate		11.99%	11.18%
Acquisition Date		Mar. 12, 2021	Mar. 12, 2021
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 704	$ 710
Amortized Cost		704	710
Fair Value		$ 692	$ 709
% of Net Assets		0.30%	0.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, One, due 6/29/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:OceanaAustralianFixedIncomeTrustMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			10.75%
Acquisition Date			Jun. 29, 2021
Maturity			Jun. 29, 2026
Principal			$ 3,084
Amortized Cost			3,400
Fair Value			$ 3,084
% of Net Assets			1.40%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, Two, due 2/25/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:OceanaAustralianFixedIncomeTrustMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			11.50%
Acquisition Date			Feb. 25, 2021
Maturity			Feb. 25, 2026
Principal			$ 7,321
Amortized Cost			8,460
Fair Value			$ 7,321
% of Net Assets			3.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, One, due 6/22/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, Two, due 6/22/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Onit, Inc., Unitranche Secured Loans, due 5/2/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:OnitInc.Member	mrcc:OnitInc.Member
Investment, Type [Extensible Enumeration]		Unitranche Secured Loans	Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.50%	7.25%
Interest Rate		12.84%	12.30%
Acquisition Date		Dec. 20, 2021	Dec. 20, 2021
Maturity		May 02, 2025	May 02, 2025
Principal		$ 1,680	$ 1,680
Amortized Cost		1,663	1,656
Fair Value		$ 1,680	$ 1,663
% of Net Assets		0.80%	0.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, One, due 10/21/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Three, due 10/21/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Two, due 10/21/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Output Services Group Inc. Senior Secured Loans Due 6/29/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P H Beauty Holdings I I I, I N C., Senior Secured Loans, due 9/26/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Four, Preferred units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Amortized Cost		$ 9	$ 9
Fair Value		$ 42	$ 46
% of Net Assets		0%	0%
Number of shares held		916
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held			916
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, One, Preferred units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Amortized Cost		$ 58	$ 58
Fair Value		$ 268	$ 298
% of Net Assets		0.20%	0.20%
Number of shares held		5,680
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held			5,680
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Three, Preferred units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Amortized Cost		$ 1	$ 1
Fair Value		$ 6	$ 7
% of Net Assets		0%	0%
Number of shares held		132
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held			132
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Two, Preferred units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Amortized Cost		$ 9	$ 9
Fair Value		$ 41	$ 46
% of Net Assets		0%	0%
Number of shares held		5,714
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held			5,714
Investment, Identifier [Axis]: P V H C Holding Corp, Senior Secured Loans, due 2/17/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Panda Acquisition, LLC, Senior Secured Loans, due 10/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PandaAcquisitionLlcMember	mrcc:PandaAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.35%	6.35%
Interest Rate		11.74%	10.28%
Acquisition Date		Dec. 20, 2022	Dec. 20, 2022
Maturity		Oct. 18, 2028	Oct. 18, 2028
Principal		$ 4,416	$ 4,500
Amortized Cost		3,689	3,691
Fair Value		$ 3,720	$ 3,690
% of Net Assets		1.80%	1.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Paragon Healthcare Inc. Senior Secured Loan Due 1/19/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Delayed Draw Senior Secured Loans due 1/19/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Revolver Senior Secured Loan Due 1/19/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group), Senior Secured Loan due 8/2/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Five, due 12/28/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%
Interest Rate		12.01%
Acquisition Date		Apr. 05, 2023
Maturity		Dec. 28, 2026
Principal		$ 707
Amortized Cost		688
Fair Value		$ 708
% of Net Assets		0.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Four, due 12/28/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Feb. 11, 2022	Feb. 11, 2022
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 884	$ 884
Amortized Cost		884	884
Fair Value		$ 884	$ 878
% of Net Assets		0.40%	0.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/28/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Dec. 28, 2018	Dec. 28, 2018
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 9,500	$ 9,500
Amortized Cost		9,488	9,456
Fair Value		$ 9,500	$ 9,443
% of Net Assets		4.60%	4.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 03, 2023
Fair Value		$ 19
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Three, due 12/28/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Jan. 11, 2021	Jan. 11, 2021
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 1,326	$ 1,325
Amortized Cost		1,325	1,325
Fair Value		$ 1,326	$ 1,318
% of Net Assets		0.60%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Two, due 12/28/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	9.90%
Acquisition Date		Sep. 12, 2022	Sep. 12, 2022
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 530	$ 530
Amortized Cost		523	519
Fair Value		$ 530	$ 527
% of Net Assets		0.30%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc. ( Revolver), Senior Secured Loans, due 12/28/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Dec. 28, 2018	Dec. 28, 2018
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 442	$ 442
Amortized Cost		442	442
Fair Value		$ 442	$ 439
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc., Equity Securities, Class A Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		8%	8%
Acquisition Date		Dec. 28, 2018	Dec. 28, 2018
Amortized Cost		$ 473	$ 473
Fair Value		$ 860	$ 563
% of Net Assets		0.50%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held		473,082	473,082
Investment, Identifier [Axis]: Planful, Inc., Equity Securities, Class B Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Number of shares held		35,791
Investment, Identifier [Axis]: Polychem Acquisition, L L C, Senior Secured Loans, due 3/17/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Prototek LLC (Delayed Draw), Senior Secured Loans, Due 12/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PrototekLlcMember	mrcc:PrototekLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	6.50%
Interest Rate		12.32%	10.83%
Acquisition Date		Dec. 08, 2022	Dec. 08, 2022
Maturity		Dec. 08, 2027	Dec. 08, 2027
Principal		$ 768	$ 768
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Prototek LLC (Revolver), Senior Secured Loans, Due 12/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PrototekLlcMember	mrcc:PrototekLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%	6.50%
Interest Rate		12.32%	10.83%
Acquisition Date		Dec. 08, 2022	Dec. 08, 2022
Maturity		Dec. 08, 2027	Dec. 08, 2027
Principal		$ 576	$ 576
Amortized Cost		92
Fair Value		$ 90
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Prototek LLC, Senior Secured Loans, Due 12/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PrototekLlcMember	mrcc:PrototekLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.10%	6.50%
Interest Rate		12.43%	10.83%
Acquisition Date		Dec. 08, 2022	Dec. 08, 2022
Maturity		Dec. 08, 2027	Dec. 08, 2027
Principal		$ 2,488	$ 2,500
Amortized Cost		2,422	2,425
Fair Value		$ 2,432	$ 2,425
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C ( Delayed Draw), Senior Secured Loans, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.62%
Acquisition Date			Dec. 07, 2021
Maturity			Oct. 20, 2025
Principal			$ 1,772
Amortized Cost			383
Fair Value			$ 381
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securites, Two, Warrants
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 19, 2021	Oct. 19, 2021
Maturity		Mar. 17, 2028	Mar. 19, 2028
Fair Value		$ 185	$ 147
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Warrants to Purchase Percentage of Equity		0.20%	0.20%
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securities, One, Warrants
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 19, 2020	Oct. 19, 2020
Maturity		Mar. 17, 2028	Mar. 19, 2028
Amortized Cost		$ 67	$ 67
Fair Value		$ 264	$ 210
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Warrants to Purchase Percentage of Equity		0.20%	0.20%
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, One, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.61%	6.50%
Interest Rate		11.94%	10.62%
Acquisition Date		Oct. 19, 2020	Oct. 19, 2020
Maturity		Oct. 20, 2025	Oct. 20, 2025
Principal		$ 854	$ 972
Amortized Cost		797	908
Fair Value		$ 854	$ 972
% of Net Assets		0.40%	0.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Three, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.61%	6.50%
Interest Rate		11.94%	10.62%
Acquisition Date		Dec. 07, 2021	Dec. 07, 2021
Maturity		Oct. 20, 2025	Oct. 20, 2025
Principal		$ 3,335	$ 3,796
Amortized Cost		3,296	3,738
Fair Value		$ 3,319	$ 3,781
% of Net Assets		1.60%	1.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Two, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.61%	6.50%
Interest Rate		11.94%	10.62%
Acquisition Date		Oct. 19, 2020	Oct. 19, 2020
Maturity		Oct. 20, 2025	Oct. 20, 2025
Principal		$ 938	$ 1,068
Amortized Cost		938	1,068
Fair Value		$ 938	$ 1,067
% of Net Assets		0.40%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, LLC, Senior Secured Loans, Four, Due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.61%
Interest Rate		11.94%
Acquisition Date		Dec. 07, 2021
Maturity		Oct. 20, 2025
Principal		$ 336
Amortized Cost		336
Fair Value		$ 335
% of Net Assets		0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Radiology Partners, Inc., Senior Secured Loans, due 7/9/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Recorded Future, Inc, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Recorded Future, Inc [ Member]	Recorded Future, Inc [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jul. 03, 2019	Jul. 03, 2019
Amortized Cost		$ 81	$ 81
Fair Value		$ 281	$ 225
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		80,486	80,486
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C ( Revolver), Senior Secured Loans, due 8/4/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RecycledPlasticsIndustriesLLCMember	mrcc:RecycledPlasticsIndustriesLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.85%	6.75%
Interest Rate		12.18%	10.87%
Acquisition Date		Aug. 04, 2021	Aug. 04, 2021
Maturity		Aug. 04, 2026	Aug. 04, 2026
Principal		$ 473	$ 473
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C, Senior Secured Loans, due 8/4/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RecycledPlasticsIndustriesLLCMember	mrcc:RecycledPlasticsIndustriesLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.85%	6.75%
Interest Rate		12.18%	10.87%
Acquisition Date		Aug. 04, 2021	Aug. 04, 2021
Maturity		Aug. 04, 2026	Aug. 04, 2026
Principal		$ 3,308	$ 3,456
Amortized Cost		3,265	3,403
Fair Value		$ 3,254	$ 3,370
% of Net Assets		1.60%	1.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relativity O D A L L C ( Revolver), Senior Secured Loans, due 5/12/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelativityODALLCMember	mrcc:RelativityODALLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.60%	7.50%
Interest rate paid in kind		11.92%	11.89%
Acquisition Date		May 12, 2021	May 12, 2021
Maturity		May 12, 2027	May 12, 2027
Principal		$ 180	$ 180
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relativity O D A L L C, Senior Secured Loans, due 5/12/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelativityODALLCMember	mrcc:RelativityODALLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.60%	7.50%
Interest rate paid in kind		11.92%	11.89%
Acquisition Date		May 12, 2021	May 12, 2021
Maturity		May 12, 2027	May 12, 2027
Principal		$ 2,107	$ 2,061
Amortized Cost		2,074	2,024
Fair Value		$ 2,110	$ 2,060
% of Net Assets		1%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Delayed Draw), Senior Secured Loans, due, 11/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			5.75%
Interest Rate			9.97%
Acquisition Date			Nov. 20, 2020
Maturity			Nov. 20, 2025
Principal			$ 778
Amortized Cost			659
Fair Value			$ 648
% of Net Assets			0.30%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Revolver), Senior Secured Loans, due, 11/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6%	5.75%
Interest Rate		11.43%	9.97%
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
Maturity		Nov. 20, 2025	Nov. 20, 2025
Principal		$ 316	$ 316
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, Class B common units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		40	40
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, preferred units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		12%	12%
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
Amortized Cost		$ 40	$ 40
Fair Value		$ 39	$ 36
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	false
Number of units held		40	40
Investment, Identifier [Axis]: Relevate Health Group, L L C, Senior Secured Loans, due, 11/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6%	5.75%
Interest Rate		11.43%	9.97%
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
Maturity		Nov. 20, 2025	Nov. 20, 2025
Principal		$ 654	$ 1,474
Amortized Cost		654	1,455
Fair Value		$ 652	$ 1,449
% of Net Assets		0.30%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relevate Health Group, LLC, Senior Secured Loans, Two, Due 11/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6%
Interest Rate		11.43%
Acquisition Date		Nov. 20, 2020
Maturity		Nov. 20, 2025
Principal		$ 1,463
Amortized Cost		1,449
Fair Value		$ 1,458
% of Net Assets		0.70%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Research Now Group, Inc. and Survey Sampling International, L L C, Senior Secured Loans, due 12/20/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Rockdale Blackhawk, L L C, Senior Secured Loans, no stated maturity
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RockdaleBlackhawkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Mar. 31, 2015
Fair Value			$ 557
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Rockdale Blackhawk, LLC, Senior Secured Loans, due, 11/30/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RockdaleBlackhawkLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Mar. 31, 2015
Fair Value		$ 527
% of Net Assets		0.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Runner Buyer I N C., Senior Secured Loans, due 10/23/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S F R Holdco, L L C Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	S F R Holdco, L L C [ Member]	S F R Holdco, L L C [ Member]
Fair Value				$ 3,900	3,900
Percentage of interests		24.40%
Investment, Identifier [Axis]: S F R Holdco, L L C, Junior Secured Loans Due 7/28/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		S F R Holdco, L L C [ Member]
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FinanceInsuranceAndRealEstateSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate		8%
Acquisition Date		Aug. 06, 2021
Maturity		Jul. 28, 2028
Principal		$ 5,850
Amortized Cost		5,850
Fair Value		$ 6,358	$ 5,850	$ 5,850	5,850
% of Net Assets		3.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: S I R V A Worldwide Inc., Senior Secured Loans, due 8/4/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S T A T S Intermediate Holdings, L L C, Senior Secured Loans, due 7/10/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S W Ingredients Holdings, L L C, Senior Secured Loans, due 7/3/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: SFR Holdco, LLC, Equity Securities, 24.4% of Interest
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		S F R Holdco, L L C [ Member]	mrcc:SfrHoldcoLlcEquitySecurities24.4OfInterestMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 06, 2021	Aug. 06, 2021
Principal		$ 0
Amortized Cost		3,900	$ 3,900
Fair Value		$ 4,239	$ 3,900
% of Net Assets		2%	1.70%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	false
Percentage of units held		24.40%		24.40%
Percentage of interests			24.40%
Investment, Identifier [Axis]: Sandvine Corporation, Senior Secured Loans, due 10/31/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C ( Revolver), Senior Secured Loans, Due 8/9/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Second Avenue S F R Holdings I I L L C [ Member]	Second Avenue S F R Holdings I I L L C [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7%	7%
Interest Rate		12.33%	11.12%
Acquisition Date		Aug. 11, 2021	Aug. 11, 2021
Maturity		Aug. 09, 2024	Aug. 09, 2024
Principal		$ 4,875	$ 4,875
Amortized Cost		4,785	4,785
Fair Value		$ 4,761	$ 4,755	$ 4,767	2,104
% of Net Assets		2.40%	2.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C, Junior Secured Loans, Due 7/28/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Second Avenue S F R Holdings I I L L C [ Member]
Investment, Type [Extensible Enumeration]			Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			8%
Acquisition Date			Aug. 06, 2021
Maturity			Jul. 28, 2028
Principal			$ 5,850
Amortized Cost			5,850
Fair Value			$ 5,850
% of Net Assets			2.60%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Secretariat Advisors L L C, Senior Secured Loans, due 12/29/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Secretariat Advisors LLC, Senior Secured Loans, Two, due 12/29/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Five, due 9/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.10%	6%
Interest Rate		11.42%	10.40%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 1,524	$ 1,535
Amortized Cost		1,524	1,535
Fair Value		$ 1,524	$ 1,532
% of Net Assets		0.70%	0.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Four, due 9/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 2,119	$ 2,135
Amortized Cost		2,119	2,135
Fair Value		$ 2,119	$ 2,131
% of Net Assets		1%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, One, due 9/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 3,353	$ 3,378
Amortized Cost		3,340	3,353
Fair Value		$ 3,353	$ 3,372
% of Net Assets		1.60%	1.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Three, due 9/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Sep. 30, 2021	Sep. 30, 2021
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 7,840	$ 7,900
Amortized Cost		7,793	7,806
Fair Value		$ 7,840	$ 7,884
% of Net Assets		3.80%	3.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Two, due 9/30/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 2,412	$ 2,430
Amortized Cost		2,412	2,430
Fair Value		$ 2,412	$ 2,425
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran Bio Science, L L C ( Revolver), Senior Secured Loans, due 7/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%	6.25%
Interest Rate		11.50%	9.96%
Interest rate paid in cash			7.86%
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Maturity		Jul. 08, 2027	Jul. 08, 2027
Principal		$ 444	$ 444
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran Bio Science, L L C, Equity Securities, common units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Amortized Cost		$ 334	$ 334
Fair Value		$ 737	$ 537
% of Net Assets		0.40%	0.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		33,333	33,333
Investment, Identifier [Axis]: Seran Bio Science, L L C, Senior Secured Loans, due 7/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%	6.25%
Interest Rate		11.50%	9.96%
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Maturity		Jul. 08, 2027	Jul. 08, 2027
Principal		$ 2,438	$ 2,456
Amortized Cost		2,413	2,424
Fair Value		$ 2,425	$ 2,435
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran BioScience, LLC (Delayed Draw), Senior Secured Loans, Due 7/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%	6.25%
Interest Rate		11.70%	10.67%
Acquisition Date		Jul. 08, 2022	Jul. 08, 2022
Maturity		Jul. 08, 2027	Jul. 08, 2027
Principal		$ 2,762	$ 2,776
Amortized Cost		2,540	1,331
Fair Value		$ 2,527	$ 1,320
% of Net Assets		1.20%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran Bioscience Llc (Delayed Draw) One Senior Secured Loans Due 7/8/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%
Interest Rate		11.70%
Acquisition Date		Aug. 21, 2023
Maturity		Jul. 08, 2027
Principal		$ 1,444
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Service Max, Inc. ( Revolver) , Senior Secured Loans, due 11/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ServiceMaxIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			6%
Interest rate paid in kind			10.27%
Acquisition Date			Nov. 01, 2021
Maturity			Nov. 01, 2027
Principal			$ 350
Amortized Cost			175
Fair Value			$ 175
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Service Max, Inc., Senior Secured Loans, due 11/1/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ServiceMaxIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			7%
Interest rate paid in kind			11.12%
Acquisition Date			Nov. 01, 2021
Maturity			Nov. 01, 2027
Principal			$ 3,846
Amortized Cost			3,786
Fair Value			$ 3,884
% of Net Assets			1.70%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Sparq Holdings Inc. Delayed Draw Senior Secured Loans Due 6/15/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%
Interest Rate		11.64%
Acquisition Date		Jun. 16, 2023
Maturity		Jun. 15, 2029
Principal		$ 222
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Sparq Holdings Inc. Revolver Senior Secured Loans Due 6/15/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%
Interest Rate		11.64%
Acquisition Date		Jun. 16, 2023
Maturity		Jun. 15, 2029
Principal		$ 205
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Sparq Holdings Inc. Senior Secured Loans Due 6/15/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.25%
Interest Rate		11.64%
Acquisition Date		Jun. 16, 2023
Maturity		Jun. 15, 2029
Principal		$ 998
Amortized Cost		968
Fair Value		$ 998
% of Net Assets		0.50%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Sparq Holdings, Inc. Senior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jun. 15, 2023
Amortized Cost		$ 300
Fair Value		$ 305
% of Net Assets		0.10%
Number of shares held		300,000
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Spectrum Science Communications, L L C ( Revolver), Senior Secured Loans, due 1/25/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SpectrumScienceCommunicationsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.25%
Interest Rate			10.92%
Acquisition Date			Jan. 25, 2022
Maturity			Jan. 25, 2027
Principal			$ 200
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Spectrum Science Communications, L L C, Senior Secured Loans, due 1/25/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SpectrumScienceCommunicationsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.25%
Interest Rate			10.92%
Acquisition Date			Jan. 25, 2022
Maturity			Jan. 25, 2027
Principal			$ 995
Amortized Cost			979
Fair Value			$ 1,005
% of Net Assets			0.40%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Spherix Global Inc, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SpherixGlobalIncMember	mrcc:SpherixGlobalInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 22, 2021	Dec. 22, 2021
Amortized Cost		$ 81	$ 81
Fair Value		$ 54	$ 63
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	true
Number of units held		81	81
Investment, Identifier [Axis]: Spherix Global Inc. ( Revolver), Senior Secured Loans, due, 12/22/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SpherixGlobalInc.Member	mrcc:SpherixGlobalIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.36%	6%
Interest Rate		13.69%	10.24%
Acquisition Date		Dec. 22, 2021	Dec. 22, 2021
Maturity		Dec. 22, 2026	Dec. 22, 2026
Principal		$ 122	$ 122
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Spherix Global Inc. , Senior Secured Loans, due, 12/22/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SpherixGlobalInc.Member	mrcc:SpherixGlobalIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.36%	6%
Interest Rate		13.69%	10.24%
Acquisition Date		Dec. 22, 2021	Dec. 22, 2021
Maturity		Dec. 22, 2026	Dec. 22, 2026
Principal		$ 1,084	$ 1,092
Amortized Cost		1,070	1,076
Fair Value		$ 1,058	$ 1,088
% of Net Assets		0.50%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Delayed Draw), Due 11/3/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SportsOperatingHoldingsIiLlcMember	mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.85%	5.75%
Interest Rate		11.17%	10.17%
Acquisition Date		Nov. 03, 2022	Nov. 03, 2022
Maturity		Nov. 03, 2027	Nov. 03, 2027
Principal		$ 2,399	$ 2,400
Amortized Cost		242
Fair Value		$ 243
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Revolver), Due, 11/3/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SportsOperatingHoldingsIiLlcMember	mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Retail	Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.85%	5.75%
Interest Rate		11.17%	10.17%
Acquisition Date		Nov. 03, 2022	Nov. 03, 2022
Maturity		Nov. 03, 2027	Nov. 03, 2027
Principal		$ 519	$ 519
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC, Due, 11/3/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SportsOperatingHoldingsIiLlcMember	mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.85%	5.75%
Interest Rate		11.17%	10.17%
Acquisition Date		Nov. 03, 2022	Nov. 03, 2022
Maturity		Nov. 03, 2027	Nov. 03, 2027
Principal		$ 2,970	$ 2,993
Amortized Cost		2,907	2,920
Fair Value		$ 2,985	$ 2,918
% of Net Assets		1.50%	1.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, ( Revolver), Senior Secured Loans, due 1/12/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember	mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.85%	6.75%
Interest Rate		12.24%	11.14%
Acquisition Date		Jan. 12, 2021	Jan. 12, 2021
Maturity		Jan. 12, 2027	Jan. 12, 2027
Principal		$ 323	$ 322
Amortized Cost		190	81
Fair Value		$ 189	$ 79
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, One, due 1/12/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember	mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.85%	6.75%
Interest Rate		12.24%	11.48%
Acquisition Date		Jan. 12, 2021	Jan. 12, 2021
Maturity		Jan. 12, 2027	Jan. 12, 2027
Principal		$ 2,000	$ 2,000
Amortized Cost		1,976	1,971
Fair Value		$ 1,988	$ 1,968
% of Net Assets		0.90%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Three, due 1/12/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.85%
Interest Rate		12.24%
Acquisition Date		May 31, 2023
Maturity		Jan. 12, 2027
Principal		$ 256
Amortized Cost		251
Fair Value		$ 255
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Two, due 1/12/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember	mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		6.85%	6.75%
Interest Rate		12.24%	11.48%
Acquisition Date		Oct. 12, 2021	Oct. 12, 2021
Maturity		Jan. 12, 2027	Jan. 12, 2027
Principal		$ 335	$ 336
Amortized Cost		331	330
Fair Value		$ 333	$ 330
% of Net Assets		0.20%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T A T T Buyer, L L C, Senior Secured Loans, due 3/30/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, One, due 4/17/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TCFIIIOWLBuyerLLCMember	mrcc:TCFIIIOWLBuyerLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building	Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.61%	5.50%
Interest Rate		10.93%	9.94%
Acquisition Date		Apr. 19, 2021	Apr. 19, 2021
Maturity		Apr. 17, 2026	Apr. 17, 2026
Principal		$ 2,004	$ 2,019
Amortized Cost		1,984	1,994
Fair Value		$ 2,004	$ 2,022
% of Net Assets		1%	0.90%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Three, due 4/17/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TCFIIIOWLBuyerLLCMember	mrcc:TCFIIIOWLBuyerLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building	Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.61%	5.50%
Interest Rate		10.93%	9.94%
Acquisition Date		Dec. 17, 2021	Dec. 17, 2021
Maturity		Apr. 17, 2026	Apr. 17, 2026
Principal		$ 2,196	$ 2,213
Amortized Cost		2,171	2,182
Fair Value		$ 2,196	$ 2,215
% of Net Assets		1%	1%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Two, due 4/17/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TCFIIIOWLBuyerLLCMember	mrcc:TCFIIIOWLBuyerLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building	Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		5.61%	5.50%
Interest Rate		10.93%	9.94%
Acquisition Date		Apr. 19, 2021	Apr. 19, 2021
Maturity		Apr. 17, 2026	Apr. 17, 2026
Principal		$ 2,447	$ 2,466
Amortized Cost		2,447	2,466
Fair Value		$ 2,447	$ 2,469
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T E A M Public Choices, L L C, Senior Secured Loans, due 12/17/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T G G T S Acquisition Company, Senior Secured Loans, due 12/12/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J C Spartech Acquisition Corp., Senior Secured Loans, due 5/5/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J Management Hold Co L L C ( Revolver), Senior Secured Loans, Due 6/28/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	Beverage, Food & Tobacco
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		5.61%	5.50%
Interest Rate		10.93%	9.89%
Acquisition Date		Sep. 09, 2020	Sep. 09, 2020
Maturity		Jun. 28, 2024	Jun. 28, 2024
Principal		$ 477	$ 477
Amortized Cost		80	80
Fair Value		$ 80	$ 80	80
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T J Management Hold Co L L C, Equity Securities, Common stock
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Sep. 09, 2020	Sep. 09, 2020
Principal		$ 0
Amortized Cost		1,631	$ 1,631
Fair Value		$ 3,183	$ 2,766	$ 2,741	3,148
% of Net Assets		1.50%	1.20%
Number of shares held		16		16
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	false
Investment, Identifier [Axis]: TJ Management HoldCo LLC, Equity Securities, due 9/9/2020
CONSOLIDATED SCHEDULE OF INVESTMENTS
Number of shares held			16
Investment, Identifier [Axis]: Tait L L C ( Revolver), Senior Secured Loans, due 3/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Tait L L C, Senior Secured Loans, due 3/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Teneo Holdings L L C, Senior Secured Loans, due 7/11/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Cook & Boardman Group L L C, Senior Secured Loans, due 10/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kleinfelder Group, Inc., Senior Secured Loans, due 11/29/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kyjen Company, L L C ( Revolver), Senior Secured Loans, due 4/3/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TheKyjenCompanyLLCMember	mrcc:TheKyjenCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.75%	7.10%
Interest rate paid in cash		12.21%
Interest rate paid in kind		1%	0.50%
Acquisition Date		May 14, 2021	May 14, 2021
Maturity		Apr. 03, 2026	Apr. 03, 2026
Principal		$ 105	$ 105
Amortized Cost			89
Fair Value			$ 88
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior SEcured Loans, Two, Due 4/3/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TheKyjenCompanyLLCMember	mrcc:TheKyjenCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.50%	7%
Interest rate paid in cash			10.92%
Interest rate paid in kind		12.96%	11.42%
Acquisition Date		Sep. 13, 2022	Sep. 13, 2022
Maturity		Apr. 03, 2026	Apr. 03, 2026
Principal		$ 1
Amortized Cost		1
Fair Value		$ 1
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior Secured Loans, due 4/3/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TheKyjenCompanyLLCMember	mrcc:TheKyjenCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.75%	7.15%
Interest rate paid in cash		12.21%	11.15%
Interest rate paid in kind		1%	0.50%
Acquisition Date		May 14, 2021	May 14, 2021
Maturity		Apr. 03, 2026	Apr. 03, 2026
Principal		$ 988	$ 986
Amortized Cost		982	979
Fair Value		$ 979	$ 975
% of Net Assets		0.50%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Thrasio, L L C, Senior Secured Loans, due 12/18/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ThrasioLLCMember	mrcc:ThrasioLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.26%	7%
Interest Rate		12.65%	11.73%
Acquisition Date		Dec. 18, 2020	Dec. 18, 2020
Maturity		Dec. 18, 2026	Dec. 18, 2026
Principal		$ 2,433	$ 2,445
Amortized Cost		2,432	2,440
Fair Value		$ 2,043	$ 2,445
% of Net Assets		1%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Delayed Draw), Senior Secured Loans, due 2/16/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TigerConnectIncMember	mrcc:TigerConnectIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.75%	7.25%
Interest Rate		12.27%
Interest rate paid in kind			3.63%
Acquisition Date		Feb. 16, 2022	Feb. 16, 2022
Maturity		Feb. 16, 2028	Feb. 16, 2028
Principal		$ 225	$ 124
Amortized Cost		109	28
Fair Value		$ 106	$ 27
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Revolver), Senior Secured Loans, due 2/16/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TigerConnectIncMember	mrcc:TigerConnectIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.75%	7.25%
Interest Rate		12.27%	11.49%
Acquisition Date		Feb. 16, 2022	Feb. 16, 2022
Maturity		Feb. 16, 2028	Feb. 16, 2028
Principal		$ 429	$ 429
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Tiger Connect, Inc., Senior Secured Loans, due 2/16/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TigerConnectIncMember	mrcc:TigerConnectIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6.75%	7.25%
Interest Rate		12.27%
Interest rate paid in cash			7.86%
Interest rate paid in kind			3.63%
Acquisition Date		Feb. 16, 2022	Feb. 16, 2022
Maturity		Feb. 16, 2028	Feb. 16, 2028
Principal		$ 3,000	$ 3,000
Amortized Cost		2,954	2,947
Fair Value		$ 2,940	$ 2,963
% of Net Assets		1.40%	1.30%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Trident Maritime Systems, Inc ( Revolver), Senior Secured Loans, due 2/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, One, due 2/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, Two, due 2/26/2027
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, One, due 12/14/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, Two, due 12/14/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck-Lite Co., LLC, Senior Secured Loans, Three, due 12/14/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: V B E1, L L C ( Delayed Draw), Unitranche Secured Loans, due 11/18/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VBE1LLCMember
Investment, Type [Extensible Enumeration]		Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.75%
Interest Rate		13.14%
Acquisition Date		Nov. 18, 2020
Maturity		Nov. 18, 2026
Principal		$ 2,250
Amortized Cost		2,250
Fair Value		$ 2,250
% of Net Assets		1.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: V B E1, L L C, Unitranche Secured Loans, due 11/18/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VBE1LLCMember
Investment, Type [Extensible Enumeration]			Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			7.65%
Interest Rate			12.38%
Acquisition Date			Nov. 18, 2020
Maturity			Nov. 18, 2026
Principal			$ 2,250
Amortized Cost			2,250
Fair Value			$ 2,257
% of Net Assets			1%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: V P S Holdings, L L C ( Revolver), Senior Secured Loans, due 10/4/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VPSHoldingsLLCMember	mrcc:VPSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.11%	9%
Interest Rate		12.43%
Interest rate paid in cash			11.39%
Interest rate paid in kind			2%
Acquisition Date		Oct. 05, 2018	Oct. 05, 2018
Maturity		Oct. 04, 2024	Oct. 04, 2024
Principal		$ 1,003	$ 1,002
Amortized Cost		703	102
Fair Value		$ 703	$ 102
% of Net Assets		0.30%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, One, due 10/4/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VPSHoldingsLLCMember	mrcc:VPSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.11%	9%
Interest Rate		12.43%
Interest rate paid in cash			11.39%
Interest rate paid in kind			2%
Acquisition Date		Oct. 05, 2018	Oct. 05, 2018
Maturity		Oct. 04, 2024	Oct. 04, 2024
Principal		$ 2,565	$ 3,246
Amortized Cost		2,554	3,222
Fair Value		$ 2,570	$ 3,252
% of Net Assets		1.20%	1.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, Two, due 10/4/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VPSHoldingsLLCMember	mrcc:VPSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Spread Above Index		7.11%	9%
Interest Rate		12.43%
Interest rate paid in cash			11.39%
Interest rate paid in kind			2%
Acquisition Date		Oct. 05, 2018	Oct. 05, 2018
Maturity		Oct. 04, 2024	Oct. 04, 2024
Principal		$ 2,107	$ 2,656
Amortized Cost		2,107	2,656
Fair Value		$ 2,112	$ 2,661
% of Net Assets		1%	1.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: V10 Entertainment, Inc, Equity Securities, Common Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		V10 Entertainment, Inc. [Member]
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jan. 12, 2023
Amortized Cost		$ 203
Fair Value		$ 185
% of Net Assets		0.10%
Number of shares held		392,157
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: V10 Entertainment, Inc. (Revolver), Senior Secured Loans, Due 1/12/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		V10 Entertainment, Inc. [Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Retail
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.10%
Interest Rate		12.35%
Acquisition Date		Jan. 12, 2023
Maturity		Jan. 12, 2028
Principal		$ 458
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: V10 Entertainment, Inc., Senior Secured Loans, Due 1/12/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Name [Extensible Enumeration]		V10 Entertainment, Inc. [Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Retail
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.10%
Interest Rate		12.35%
Acquisition Date		Jan. 12, 2023
Maturity		Jan. 12, 2028
Principal		$ 3,990
Amortized Cost		3,884
Fair Value		$ 4,016
% of Net Assets		2%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products L L C ( Revolver), Senior Secured Loans, due 6/19/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			9.50%
Interest Rate			13.89%
Acquisition Date			Jun. 18, 2018
Maturity			Jun. 19, 2023
Principal			$ 1,095
Amortized Cost			55
Fair Value			$ 55
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products L L C , Equity Securities, Class A-1 units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember	mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber	Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		10%	10%
Acquisition Date		Jun. 18, 2018	Jun. 18, 2018
Amortized Cost		$ 501	$ 501
Fair Value		$ 402	$ 555
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held		501,014	501,014
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, One, due 6/19/2023,
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			7.50%
Interest rate paid in cash			10.39%
Interest rate paid in kind			1.50%
Acquisition Date			Jun. 18, 2018
Maturity			Jun. 19, 2023
Principal			$ 1,609
Amortized Cost			1,606
Fair Value			$ 1,958
% of Net Assets			0.90%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Three, due 6/19/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			7.50%
Interest rate paid in kind			11.89%
Acquisition Date			Dec. 22, 2021
Maturity			Jun. 19, 2023
Principal			$ 502
Amortized Cost			502
Fair Value			$ 1,565
% of Net Assets			0.70%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Two, due 6/19/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			7.50%
Interest Rate			11.89%
Acquisition Date			Jun. 18, 2018
Maturity			Jun. 19, 2023
Principal			$ 260
Amortized Cost			260
Fair Value			$ 312
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products LLC (Revolver), Senior Secured Loans, due 9/15/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.61%
Interest Rate		12.93%
Acquisition Date		Jun. 18, 2018
Maturity		Dec. 29, 2023
Principal		$ 1,095
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, One, due 9/15/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.61%
Interest rate paid in cash		11.43%
Interest rate paid in kind		1.50%
Acquisition Date		Jun. 18, 2018
Maturity		Dec. 29, 2023
Principal		$ 1,628
Amortized Cost		1,628
Fair Value		$ 1,895
% of Net Assets		0.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Three, due 9/15/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.61%
Interest Rate		12.93%
Acquisition Date		Dec. 22, 2021
Maturity		Dec. 29, 2023
Principal		$ 502
Amortized Cost		502
Fair Value		$ 1,423
% of Net Assets		0.70%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Two, due 9/15/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.50%
Interest rate paid in cash		1%
Interest rate paid in kind		12.93%
Acquisition Date		Jun. 18, 2018
Maturity		Dec. 29, 2023
Principal		$ 286
Amortized Cost		286
Fair Value		$ 276
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Delayed Draw), Senior Secured Loans, due 6/8/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VhagarPurchaserLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%
Interest Rate		12.37%
Acquisition Date		Jun. 09, 2023
Maturity		Jun. 08, 2029
Principal		$ 667
Amortized Cost		150
Fair Value		$ 150
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Revolver), Senior Secured Loans, due, 6/8/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VhagarPurchaserLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%
Interest Rate		12.24%
Acquisition Date		Jun. 09, 2023
Maturity		Jun. 08, 2029
Principal		$ 333
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vhagar Purchaser, LLC, Senior Secured Loans, due 6/8/2029
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VhagarPurchaserLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7%
Interest Rate		12.24%
Acquisition Date		Jun. 09, 2023
Maturity		Jun. 08, 2029
Principal		$ 3,000
Amortized Cost		2,915
Fair Value		$ 3,000
% of Net Assets		1.40%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Equity Securities, Class A Units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jul. 31, 2023
Amortized Cost		$ 1,480
Fair Value		$ 1,342
% of Net Assets		0.60%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Number of units held		1,480,000
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Five, due 1/31/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.26%
Interest Rate		13.63%
Acquisition Date		Jul. 31, 2023
Maturity		Jan. 31, 2028
Principal		$ 511
Amortized Cost		511
Fair Value		$ 463
% of Net Assets		0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Four, No Maturity Date
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 02, 2019
Principal		$ 76
Amortized Cost		$ 76
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, One, No Maturity Date
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 02, 2019
Principal		$ 637
Amortized Cost		$ 637
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Three, No Maturity Date
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 02, 2019
Principal		$ 200
Amortized Cost		$ 200
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Two, No Maturity Date
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Nov. 04, 2019
Principal		$ 122
Amortized Cost		$ 122
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, One, due 1/31/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.26%
Interest Rate		13.63%
Acquisition Date		Jul. 31, 2023
Maturity		Jan. 31, 2028
Principal		$ 196
Amortized Cost		196
Fair Value		$ 196
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Three, due 1/31/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.26%
Interest Rate		13.63%
Acquisition Date		Jul. 31, 2023
Maturity		Jan. 31, 2028
Principal		$ 648
Amortized Cost		648
Fair Value		$ 648
% of Net Assets		0.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Two, due 12/12/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.26%
Interest Rate		13.66%
Acquisition Date		Sep. 08, 2023
Maturity		Dec. 12, 2028
Principal		$ 114
Amortized Cost		114
Fair Value		$ 114
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Four, due 5/12/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			12%
Interest rate paid in cash			4.25%
Interest rate paid in kind			12%
Acquisition Date			May 02, 2019
Maturity			May 12, 2023
Principal			$ 200
Amortized Cost			200
Fair Value			$ 196
% of Net Assets			0.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, One, due 5/12/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			12%
Interest rate paid in cash			4.51%
Interest rate paid in kind			12%
Acquisition Date			May 02, 2019
Maturity			May 12, 2023
Principal			$ 1,691
Amortized Cost			1,691
Fair Value			$ 1,657
% of Net Assets			0.70%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Three, due 5/12/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			12%
Interest rate paid in cash			4.42%
Interest rate paid in kind			12%
Acquisition Date			May 02, 2019
Maturity			May 12, 2023
Principal			$ 531
Amortized Cost			531
Fair Value			$ 520
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Two, due 5/12/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			12%
Interest rate paid in cash			4.51%
Interest rate paid in kind			12%
Acquisition Date			Nov. 04, 2019
Maturity			May 12, 2023
Principal			$ 325
Amortized Cost			325
Fair Value			$ 318
% of Net Assets			0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Four, due 2/6/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest rate paid in kind			2%
Acquisition Date			Dec. 26, 2014
Maturity			Feb. 06, 2024
Principal			$ 1,149
Amortized Cost			$ 1,149
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, One, due 2/6/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest rate paid in kind			2%
Acquisition Date			Jul. 06, 2018
Maturity			Feb. 06, 2024
Principal			$ 7,026
Amortized Cost			$ 7,026
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Three, due 2/6/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest rate paid in kind			2%
Acquisition Date			Dec. 26, 2014
Maturity			Feb. 06, 2024
Principal			$ 13,552
Amortized Cost			$ 13,528
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Two, due 2/6/2024
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest rate paid in kind			2%
Acquisition Date			Mar. 09, 2018
Maturity			Feb. 06, 2024
Principal			$ 3,065
Amortized Cost			$ 3,065
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: W3 Monroe R E Debt L L C, Senior Secured Loans, due 2/4/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:W3MonroeREDebtLLCMember	mrcc:W3MonroeREDebtLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember	mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate			10%
Interest rate paid in kind		10%
Acquisition Date		Feb. 05, 2021	Feb. 05, 2021
Maturity		Feb. 04, 2028	Feb. 04, 2028
Principal		$ 3,456	$ 3,210
Amortized Cost		3,456	3,210
Fair Value		$ 3,437	$ 3,210
% of Net Assets		1.70%	1.40%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: W3 Monroe RE Debt LLC (Delayed Draw), Senior Secured Loans, Due 2/4/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:W3MonroeREDebtLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest rate paid in kind		10%
Acquisition Date		Mar. 31, 2023
Maturity		Feb. 04, 2028
Principal		$ 134
Amortized Cost		81
Fair Value		$ 80
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Wheel Pros, Inc., Senior Secured Loans, due 5/11/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Delayed Draw), Senior Secured Loans, due 6/2/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.75%
Interest Rate			11.17%
Acquisition Date			Jun. 03, 2022
Maturity			Jun. 02, 2028
Principal			$ 1,406
Amortized Cost			56
Fair Value			$ 56
% of Net Assets			0%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Revolver), Senior Secured Loans, due 6/2/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WhistlerParentHoldingsIIIIncMember	mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.90%	6.75%
Interest Rate			11.17%
Interest rate paid in cash		9.52%
Interest rate paid in kind		4.75%
Acquisition Date		Jun. 03, 2022	Jun. 03, 2022
Maturity		Jun. 02, 2028	Jun. 02, 2028
Principal		$ 563	$ 563
Amortized Cost		563	84
Fair Value		$ 557	$ 84
% of Net Assets		0.30%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc., Senior Secured Loans, due 6/2/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WhistlerParentHoldingsIIIIncMember	mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.90%	6.75%
Interest Rate			11.17%
Interest rate paid in cash		9.52%
Interest rate paid in kind		4.75%
Acquisition Date		Jun. 03, 2022	Jun. 03, 2022
Maturity		Jun. 02, 2028	Jun. 02, 2028
Principal		$ 4,500	$ 4,500
Amortized Cost		4,423	4,415
Fair Value		$ 4,457	$ 4,457
% of Net Assets		2.10%	2%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Whistler Parent Holdings III Inc. One Senior Secured Loans due 6/2/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		8.90%
Interest rate paid in cash		9.52%
Interest rate paid in kind		4.75%
Acquisition Date		Jun. 03, 2022
Maturity		Jun. 02, 2028
Principal		$ 56
Amortized Cost		56
Fair Value		$ 56
% of Net Assets		0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: WillowTree, LLC, Unitranche Secured Loans, due 10/9/2023
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WillowTreeLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Spread Above Index			5%
Interest Rate			9.39%
Acquisition Date			Oct. 09, 2018
Maturity			Oct. 09, 2023
Principal			$ 7,326
Amortized Cost			7,301
Fair Value			$ 7,326
% of Net Assets			3.30%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C ( Delayed Draw), Junior Secured Loans, due 7/2/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember	mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans	Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in cash		8%	8%
Interest rate paid in kind		4%	4%
Acquisition Date		Sep. 25, 2023	Jul. 02, 2021
Maturity		Jul. 22, 2026	Jul. 02, 2026
Principal		$ 2,141	$ 6,708
Amortized Cost		614	6,014
Fair Value		$ 603	$ 6,014
% of Net Assets		0.30%	2.70%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		false	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Equity Securities, Preferred units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember	mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in cash		8%	8%
Interest rate paid in kind		4%	4%
Acquisition Date		Jul. 02, 2021	Jul. 02, 2021
Amortized Cost		$ 2	$ 2
Fair Value		$ 1,806	$ 1,047
% of Net Assets		0.90%	0.50%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Number of units held		2,141	2,141
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, One, due 7/2/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest rate paid in cash		8%
Interest rate paid in kind		4%
Acquisition Date		Jul. 02, 2021
Maturity		Jul. 02, 2026
Principal		$ 6,832
Amortized Cost		6,832
Fair Value		$ 6,716
% of Net Assets		3.20%
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, Two, due 7/2/2026
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest rate paid in cash		8%
Interest rate paid in kind		4%
Acquisition Date		May 16, 2023
Maturity		Jul. 02, 2026
Principal		$ 1,182
Amortized Cost		1,182
Fair Value		$ 1,162
% of Net Assets		0.60%
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc, Equity Securities, Class A units
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember	mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest rate paid in kind		8%	8%
Acquisition Date		Jan. 28, 2020	Jan. 28, 2020
Amortized Cost		$ 49	$ 49
Fair Value		$ 243	$ 223
% of Net Assets		0.10%	0.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		true	false
Number of units held		49,479	49,479
Investment, Identifier [Axis]: Xan Edu Publishing, Inc. ( Revolver), Senior Secured Loans, due, 1/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember	mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6%	6.50%
Interest Rate		11.43%	10.94%
Acquisition Date		Jan. 28, 2020	Jan. 28, 2020
Maturity		Jan. 28, 2025	Jan. 28, 2025
Principal		$ 742	$ 742
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, One, due, 1/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember	mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6%	6.50%
Interest Rate		11.43%	10.94%
Acquisition Date		Jan. 28, 2020	Aug. 31, 2022
Maturity		Jan. 28, 2025	Jan. 28, 2025
Principal		$ 4,549	$ 1,822
Amortized Cost		4,514	1,782
Fair Value		$ 4,549	$ 1,829
% of Net Assets		2.20%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, Two, due, 1/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		6%
Interest Rate		11.43%
Acquisition Date		Aug. 31, 2022
Maturity		Jan. 28, 2025
Principal		$ 1,808
Amortized Cost		1,781
Fair Value		$ 1,812
% of Net Assets		0.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, due, 1/28/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			6.50%
Interest Rate			10.94%
Acquisition Date			Jan. 28, 2020
Maturity			Jan. 28, 2025
Principal			$ 4,584
Amortized Cost			4,531
Fair Value			$ 4,602
% of Net Assets			2.10%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Y S W H 4, L L C (Revolver), Senior Secured Loans, Due 11/20/2025
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:YSWH4LLCRevolverMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index			7%
Interest Rate			11.44%
Acquisition Date			Jul. 20, 2022
Maturity			Nov. 20, 2025
Principal			$ 5,250
Amortized Cost			1,776
Fair Value			$ 1,776
% of Net Assets			0.80%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: iCIMS, Inc., Senior Secured Loans, Due 8/18/2028
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IcimsIncMember	mrcc:IcimsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread Above Index		7.25%	7.25%
Interest Rate		12.63%	11.52%
Acquisition Date		Oct. 24, 2022	Oct. 24, 2022
Maturity		Aug. 18, 2028	Aug. 18, 2028
Principal		$ 2,500	$ 2,500
Amortized Cost		2,461	2,457
Fair Value		$ 2,500	$ 2,456
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false	false
International
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost			$ 11,860
Fair Value			10,405
Automotive
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 17,781	16,775
Fair Value		16,626	16,637
Banking
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		17,031	17,790
Fair Value		16,436	19,817
Beverage, Food & Tobacco
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		9,924	15,625
Fair Value		11,434	12,470
Capital Equipment
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		18,442	18,615
Fair Value		18,936	19,012
Chemicals, Plastics & Rubber
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		2,917	2,924
Fair Value		3,996	4,445
Construction & Building
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		8,698	6,642
Fair Value		8,800	6,706
Environmental Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		5,434	6,164
Fair Value		5,895	6,558
Hotels, Gaming & Leisure
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		111	2,702
Fair Value		115	2,720
Media: Advertising, Printing & Publishing
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		18,241	17,470
Fair Value		20,497	19,777
Media: Broadcasting & Subscription
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		3,984	2,747
Fair Value		2,763	2,691
Media: Diversified & Production
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		41,260	36,018
Fair Value		41,435	36,164
Retail
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		2,422	9,247
Fair Value		1,985	9,306
Telecommunications
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		7,246	7,502
Fair Value		7,356	7,595
Wholesale
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		15,993	16,044
Fair Value		14,790	14,165
Aerospace & Defense
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		7,601	7,461
Fair Value		7,578	7,436
Senior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		419,994	436,066
Fair Value		416,316	434,023
Unitranche Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		13,522	45,352
Fair Value		13,548	20,633
Junior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		29,215	21,141
Fair Value		27,425	22,193
Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		31,414	34,098
Fair Value		27,726	28,682
Non-controlled/non-affiliate company investments
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		403,578	446,964
Fair Value		$ 400,117	$ 418,913
% of Net Assets		192.80%	186.10%
Investment, Significant Unobservable Input [true false]			true
Non-controlled/non-affiliate company investments | Senior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Principal		$ 390,734	$ 425,065
Amortized Cost		349,243	366,067
Fair Value		$ 350,695	$ 365,806
% of Net Assets		169%	162.60%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Automotive
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 20,072	$ 20,441
Amortized Cost		17,401	16,395
Fair Value		$ 16,552	$ 16,326
% of Net Assets		8%	7.30%
Non-controlled/non-affiliate company investments | Senior Secured Loans | Banking
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 11,014	$ 10,773
Amortized Cost		10,485	10,134
Fair Value		$ 10,782	$ 10,345
% of Net Assets		5.20%	4.60%
Non-controlled/non-affiliate company investments | Senior Secured Loans | Beverage, Food & Tobacco
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 9,341	$ 9,782
Amortized Cost		8,213	8,446
Fair Value		$ 8,171	$ 8,358
% of Net Assets		3.90%	3.70%
Non-controlled/non-affiliate company investments | Senior Secured Loans | Capital Equipment
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 20,338	$ 20,572
Amortized Cost		18,323	18,496
Fair Value		$ 18,504	$ 18,808
% of Net Assets		8.90%	8.40%
Non-controlled/non-affiliate company investments | Senior Secured Loans | Chemicals, Plastics & Rubber
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 3,511	$ 3,466
Amortized Cost		2,416	2,423
Fair Value		$ 3,594	$ 3,890
% of Net Assets		1.70%	1.70%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Construction & Building
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 9,374	$ 6,698
Amortized Cost		8,543	6,642
Fair Value		$ 8,662	$ 6,706
% of Net Assets		4.20%	3%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Consumer Goods: Durable
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 10,717	$ 11,292
Amortized Cost		8,711	9,252
Fair Value		$ 8,671	$ 9,236
% of Net Assets		4.20%	4.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Consumer Goods: Non-Durable
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 3,527	$ 3,536
Amortized Cost		3,415	3,508
Fair Value		$ 3,023	$ 3,508
% of Net Assets		1.50%	1.60%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Environmental Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 5,463	$ 7,608
Amortized Cost		5,367	6,097
Fair Value		$ 5,446	$ 6,201
% of Net Assets		2.60%	2.80%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | FIRE: Finance
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 16,334	$ 29,660
Amortized Cost		14,508	24,944
Fair Value		$ 14,653	$ 23,495
% of Net Assets		7.10%	10.40%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | FIRE: Real Estate
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 4,464	$ 7,857
Amortized Cost		3,907	6,853
Fair Value		$ 3,954	$ 6,926
% of Net Assets		1.90%	3.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Healthcare & Pharmaceuticals
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 68,260	$ 61,092
Amortized Cost		58,527	45,636
Fair Value		$ 59,270	$ 46,159
% of Net Assets		28.60%	20.50%
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | High Tech Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 31,998	$ 42,877
Amortized Cost		29,099	38,709
Fair Value		$ 29,320	$ 38,519
% of Net Assets		14.10%	17.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Hotels, Gaming & Leisure
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal			$ 3,097
Amortized Cost			2,591
Fair Value			$ 2,611
% of Net Assets			1.10%
Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Advertising, Printing & Publishing
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 20,941	$ 20,507
Amortized Cost		17,958	17,186
Fair Value		$ 17,967	$ 17,345
% of Net Assets		8.70%	7.70%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Broadcasting & Subscription
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Principal		$ 958	$ 2,747
Amortized Cost		958	2,747
Fair Value		$ 958	$ 2,691
% of Net Assets		0.50%	1.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Diversified & Production
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 46,624	$ 43,230
Amortized Cost		40,673	35,634
Fair Value		$ 40,777	$ 35,592
% of Net Assets		19.60%	15.80%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Retail
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IcimsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Principal		$ 639	$ 8,772
Amortized Cost		402	8,535
Fair Value		$ 600	$ 8,522
% of Net Assets		0.30%	3.80%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Services: Business
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 56,367	$ 58,660
Amortized Cost		52,158	52,282
Fair Value		$ 52,498	$ 52,627
% of Net Assets		25.30%	23.40%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Services: Consumer
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 29,326	$ 30,570
Amortized Cost		27,446	28,517
Fair Value		$ 27,455	$ 28,507
% of Net Assets		13.20%	12.70%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Telecommunications
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 5,686	$ 5,998
Amortized Cost		4,954	5,210
Fair Value		$ 5,050	$ 5,269
% of Net Assets		2.40%	2.30%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Wholesale
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 15,780	$ 15,830
Amortized Cost		15,779	15,830
Fair Value		$ 14,788	$ 14,165
% of Net Assets		7.10%	6.30%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Unitranche Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 13,812	$ 45,813
Amortized Cost		13,522	45,352
Fair Value		$ 13,548	$ 20,633
% of Net Assets		6.50%	9.20%
Non-controlled/non-affiliate company investments | Unitranche Secured Loans | Consumer Goods: Non-Durable
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal			$ 24,792
Amortized Cost			$ 24,768
% of Net Assets			0%
Non-controlled/non-affiliate company investments | Unitranche Secured Loans | High Tech Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal			$ 7,326
Amortized Cost			7,301
Fair Value			$ 7,326
% of Net Assets			3.30%
Non-controlled/non-affiliate company investments | Unitranche Secured Loans | Services: Business
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 3,865	$ 3,865
Amortized Cost		3,671	3,572
Fair Value		$ 3,720	$ 3,614
% of Net Assets		1.80%	1.60%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Unitranche Secured Loans | Telecommunications
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Industry Sector [Extensible Enumeration]		Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 2,250	$ 2,250
Amortized Cost		2,250	2,250
Fair Value		$ 2,250	$ 2,257
% of Net Assets		1.10%	1%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true	true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Unitranche Secured Loans | Aerospace & Defense
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 7,697	$ 7,580
Amortized Cost		7,601	7,461
Fair Value		$ 7,578	$ 7,436
% of Net Assets		3.60%	3.30%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Junior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 25,039	$ 17,569
Amortized Cost		23,365	15,291
Fair Value		$ 21,067	$ 16,343
% of Net Assets		10.10%	7.20%
Non-controlled/non-affiliate company investments | Junior Secured Loans | Banking
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 5,625	$ 8,250
Amortized Cost		5,583	6,693
Fair Value		$ 5,654	$ 6,663
% of Net Assets		2.70%	2.90%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Junior Secured Loans | FIRE: Real Estate
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Junior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 11,000	$ 8,486
Amortized Cost		9,465	7,767
Fair Value		$ 9,326	$ 7,798
% of Net Assets		4.50%	3.50%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		false
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Junior Secured Loans | High Tech Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 4,727
Amortized Cost		4,632
Fair Value		$ 2,574
% of Net Assets		1.20%
Non-controlled/non-affiliate company investments | Junior Secured Loans | Media: Broadcasting & Subscription
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 1,546
Amortized Cost		1,546
Fair Value		$ 463
% of Net Assets		0.20%
Non-controlled/non-affiliate company investments | Junior Secured Loans | Retail
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 1,308
Amortized Cost		1,308
Fair Value		$ 965
% of Net Assets		0.50%
Non-controlled/non-affiliate company investments | Junior Secured Loans | Services: Consumer
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 833	$ 833
Amortized Cost		831	831
Fair Value		$ 2,085	$ 1,882
% of Net Assets		1%	0.80%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		false	true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 17,448	$ 20,254
Fair Value		$ 14,807	$ 16,131
% of Net Assets		7.20%	7.10%
Non-controlled/non-affiliate company investments | Equity Securities | Automotive
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Amortized Cost		$ 380	$ 380
Fair Value		$ 74	$ 311
% of Net Assets		0%	0.10%
Investment, Restriction Status [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Banking
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Amortized Cost		$ 963	$ 963
Fair Value			$ 2,809
% of Net Assets		0%	1.30%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Beverage, Food & Tobacco
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Amortized Cost			$ 5,468
Fair Value			$ 1,266
% of Net Assets			0.60%
Non-controlled/non-affiliate company investments | Equity Securities | Capital Equipment
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 119	$ 119
Fair Value		$ 432	$ 204
% of Net Assets		0.20%	0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Chemicals, Plastics & Rubber
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 501	$ 501
Fair Value		$ 402	$ 555
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Equity Securities | Construction & Building
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 155
Fair Value		$ 138
% of Net Assets		0.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Consumer Goods: Durable
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 81	$ 81
Fair Value		$ 68	$ 102
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Environmental Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 67	$ 67
Fair Value		$ 449	$ 357
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | FIRE: Finance
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Industry Sector [Extensible Enumeration]			FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 77	$ 77
Fair Value		$ 384	$ 397
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | FIRE: Real Estate
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 2	$ 2
Fair Value		$ 1,806	$ 1,047
% of Net Assets		0.90%	0.50%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Equity Securities | Healthcare & Pharmaceuticals
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 2,314	$ 1,802
Fair Value		$ 2,774	$ 2,303
% of Net Assets		1.40%	1%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | High Tech Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 984	$ 684
Fair Value		$ 1,625	$ 1,340
% of Net Assets		0.80%	0.60%
Investment, Restriction Status [true false]		true	true
Investment, Significant Unobservable Input [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Hotels, Gaming & Leisure
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 111	$ 111
Fair Value		$ 115	$ 109
% of Net Assets		0.10%	0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Media: Advertising, Printing & Publishing
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 283	$ 284
Fair Value		$ 2,530	$ 2,432
% of Net Assets		1.20%	1.10%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Media: Broadcasting & Subscription
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 1,480
Fair Value		$ 1,342
% of Net Assets		0.60%
Non-controlled/non-affiliate company investments | Equity Securities | Media: Diversified & Production
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 587	$ 384
Fair Value		$ 658	$ 572
% of Net Assets		0.30%	0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Retail
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 712	$ 712
Fair Value		$ 420	$ 784
% of Net Assets		0.20%	0.40%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Services: Business
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 395	$ 395
Fair Value		$ 1,098	$ 921
% of Net Assets		0.50%	0.40%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Services: Consumer
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 7,981	$ 7,968
Fair Value		$ 434	$ 553
% of Net Assets		0.30%	0.20%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Telecommunications
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Amortized Cost		$ 42	$ 42
Fair Value		$ 56	$ 69
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Wholesale
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Amortized Cost		$ 214	$ 214
Fair Value		$ 2
% of Net Assets		0%	0%
Investment, Restriction Status [true false]		true
Investment, Significant Unobservable Input [true false]		true
Investment, Non-income Producing [true false]		true
Non-controlled affiliate company investments
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 90,567	$ 89,693
Fair Value		$ 84,898	$ 86,618	$ 85,274	90,281
% of Net Assets		40.90%	38.50%
Non-controlled affiliate company investments | T J Management Hold Co L L C [ Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	T J Management Hold Co L L C [ Member]
Fair Value		$ 3,263	$ 2,846	2,821	3,148
Non-controlled affiliate company investments | American Community Homes, Inc. [ Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]
Fair Value		18,020	19,546	19,676	23,748
Non-controlled affiliate company investments | Second Avenue S F R Holdings I I L L C [ Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Second Avenue S F R Holdings I I L L C [ Member]
Fair Value		4,761	4,755	4,767	2,104
Non-controlled affiliate company investments | Ascent Midco, L L C [ Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Ascent Midco, L L C [ Member]
Fair Value		1,914	8,186	7,578	8,946
Non-controlled affiliate company investments | Mnine Holdings, Inc [ Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Mnine Holdings, Inc [ Member]
Fair Value		6,645	5,706	6,241	5,771
Non-controlled affiliate company investments | C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Fair Value			146	146	5,111
Non-controlled affiliate company investments | N E C B Collections, L L C [ Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	N E C B Collections, L L C [ Member]
Fair Value		424	382	426	632
Non-controlled affiliate company investments | S F R Holdco, L L C [ Member]
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	S F R Holdco, L L C [ Member]
Fair Value		10,597	9,750	9,750	9,750
Non-controlled affiliate company investments | Familia Dental Group Holdings, LLC
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Familia Dental Group Holdings, LLC
Fair Value		2,351	2,625	2,508	1,919
Non-controlled affiliate company investments | Senior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		73,784	75,344
Amortized Cost		70,751	69,999
Fair Value		$ 65,621	$ 68,217
% of Net Assets		31.60%	30.30%
Non-controlled affiliate company investments | Senior Secured Loans | Beverage, Food & Tobacco
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 477	$ 477
Amortized Cost		80	80
Fair Value		$ 80	$ 80
% of Net Assets		0%	0%
Non-controlled affiliate company investments | Senior Secured Loans | FIRE: Real Estate
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 65,306	$ 60,140
Amortized Cost		62,716	56,757
Fair Value		$ 58,472	$ 55,686
% of Net Assets		28.20%	24.70%
Non-controlled affiliate company investments | Senior Secured Loans | Healthcare & Pharmaceuticals
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Principal			$ 7,346
Amortized Cost			6,159
Fair Value			$ 6,217
% of Net Assets			2.80%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Non-controlled affiliate company investments | Senior Secured Loans | High Tech Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 6,645	$ 6,025
Amortized Cost		6,643	5,691
Fair Value		$ 6,645	$ 5,706
% of Net Assets		3.20%	2.50%
Investment, Restriction Status [true false]			true
Non-controlled affiliate company investments | Senior Secured Loans | Services: Business
CONSOLIDATED SCHEDULE OF INVESTMENTS
Fair Value			$ 146
% of Net Assets			0.10%
Non-controlled affiliate company investments | Senior Secured Loans | Services: Consumer
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Principal		$ 1,356	$ 1,356
Amortized Cost		1,312	1,312
Fair Value		$ 424	$ 382
% of Net Assets		0.20%	0.20%
Investment, Restriction Status [true false]			true
Investment, Significant Unobservable Input [true false]			true
Investment, Non-income Producing [true false]			false
Non-controlled affiliate company investments | Junior Secured Loans
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 5,850	$ 5,850
Amortized Cost		5,850	5,850
Fair Value		$ 6,358	$ 5,850
% of Net Assets		3.10%	2.60%
Non-controlled affiliate company investments | Junior Secured Loans | FIRE: Real Estate
CONSOLIDATED SCHEDULE OF INVESTMENTS
Principal		$ 5,850	$ 5,850
Amortized Cost		5,850	5,850
Fair Value		$ 6,358	$ 5,850
% of Net Assets		3.10%	2.60%
Non-controlled affiliate company investments | Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 13,966	$ 13,844
Fair Value		$ 12,919	$ 12,551
% of Net Assets		6.20%	5.60%
Non-controlled affiliate company investments | Equity Securities | Beverage, Food & Tobacco
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 1,631	$ 1,631
Fair Value		$ 3,183	$ 2,766
% of Net Assets		1.50%	1.20%
Non-controlled affiliate company investments | Equity Securities | FIRE: Real Estate
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 4,693	$ 4,693
Fair Value		$ 5,471	$ 5,191
% of Net Assets		2.60%	2.30%
Non-controlled affiliate company investments | Equity Securities | Healthcare & Pharmaceuticals
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 6,184	$ 6,062
Fair Value		$ 4,265	$ 4,594
% of Net Assets		2.10%	2.10%
Non-controlled affiliate company investments | Equity Securities | High Tech Industries
CONSOLIDATED SCHEDULE OF INVESTMENTS
% of Net Assets		0%	0%
Non-controlled affiliate company investments | Equity Securities | Services: Business
CONSOLIDATED SCHEDULE OF INVESTMENTS
% of Net Assets			0%
Non-controlled affiliate company investments | Equity Securities | Services: Consumer
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 1,458	$ 1,458
% of Net Assets		0%	0%
Controlled affiliate company investments
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		$ 42,650	$ 42,650
Fair Value		$ 33,269	$ 35,509	36,544	41,125
% of Net Assets		16%	15.80%
Controlled affiliate company investments | MRCC Senior Loan Fund I, LLC
CONSOLIDATED SCHEDULE OF INVESTMENTS
Investment, Issuer Affiliation [Extensible Enumeration]	Controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	MRCC Senior Loan Fund I, LLC
Fair Value		$ 33,269	$ 35,509	$ 36,544	$ 41,125
Controlled affiliate company investments | Equity Securities
CONSOLIDATED SCHEDULE OF INVESTMENTS
Amortized Cost		42,650	42,650
Fair Value		$ 33,269	$ 35,509
% of Net Assets		16%	15.80%

CONSOLIDATED SCHEDULE OF INVE_2

CONSOLIDATED SCHEDULE OF INVESTMENTS (Foreign currency forward contracts) $ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2022 AUD ($)
Foreign currency forward contracts
Unrealized Gain (Loss) on Derivatives	$ 1,507
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 1/17/2024
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 115
Derivative Liability, Notional Amount		$ 150
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Jan. 17, 2024
Unrealized Gain (Loss) on Derivatives	$ 13
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 1/18/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 118
Derivative Liability, Notional Amount		$ 153
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Jan. 18, 2023
Unrealized Gain (Loss) on Derivatives	$ 14
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 10/18/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 114
Derivative Liability, Notional Amount		$ 148
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Oct. 18, 2023
Unrealized Gain (Loss) on Derivatives	$ 13
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 11/16/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 107
Derivative Liability, Notional Amount		$ 140
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Nov. 16, 2023
Unrealized Gain (Loss) on Derivatives	$ 12
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 12/18/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 109
Derivative Liability, Notional Amount		$ 142
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Dec. 18, 2023
Unrealized Gain (Loss) on Derivatives	$ 12
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 2/16/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 108
Derivative Liability, Notional Amount		$ 140
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Feb. 16, 2023
Unrealized Gain (Loss) on Derivatives	$ 13
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 2/16/2024
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 110
Derivative Liability, Notional Amount		$ 143
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Feb. 16, 2024
Unrealized Gain (Loss) on Derivatives	$ 12
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 3/16/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 102
Derivative Liability, Notional Amount		$ 132
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Mar. 16, 2023
Unrealized Gain (Loss) on Derivatives	$ 12
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 3/18/2024
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 11,827
Derivative Liability, Notional Amount		$ 15,410
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Mar. 18, 2024
Unrealized Gain (Loss) on Derivatives	$ 1,329
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 4/20/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 123
Derivative Liability, Notional Amount		$ 160
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Apr. 20, 2023
Unrealized Gain (Loss) on Derivatives	$ 14
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 5/16/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 93
Derivative Liability, Notional Amount		$ 121
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	May 16, 2023
Unrealized Gain (Loss) on Derivatives	$ 11
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 6/19/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 121
Derivative Liability, Notional Amount		$ 156
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Jun. 19, 2023
Unrealized Gain (Loss) on Derivatives	$ 14
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 7/18/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 107
Derivative Liability, Notional Amount		$ 138
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Jul. 18, 2023
Unrealized Gain (Loss) on Derivatives	$ 12
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 8/16/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 113
Derivative Liability, Notional Amount		$ 146
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Aug. 16, 2023
Unrealized Gain (Loss) on Derivatives	$ 13
Open Forward Foreign Currency Contract, Identifier [Axis]: Foreign currency forward contract with settlement date 9/18/2023
Foreign currency forward contracts
Derivative Asset, Notional Amount	$ 113
Derivative Liability, Notional Amount		$ 146
Derivative Asset, Counterparty Name [Extensible Enumeration]	mrcc:BannockburnGlobalForexLlcMember	mrcc:BannockburnGlobalForexLlcMember
Derivative, Maturity Date	Sep. 18, 2023
Unrealized Gain (Loss) on Derivatives	$ 13

CONSOLIDATED SCHEDULE OF INVE_3

CONSOLIDATED SCHEDULE OF INVESTMENTS (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2020
CONSOLIDATED SCHEDULE OF INVESTMENTS
Net assets	$ 207,555	$ 225,019
IDIG Parent, LLC
CONSOLIDATED SCHEDULE OF INVESTMENTS
Commitment to fund equity investment	43
Recorded Future, Inc.
CONSOLIDATED SCHEDULE OF INVESTMENTS
Commitment to fund equity investment	$ 16
Familia Dental Group Holdings, LLC
CONSOLIDATED SCHEDULE OF INVESTMENTS
Company investments as percentage of net assets	249.70%	240.40%
Company investments as percentage of total assets	95.50%	95.80%
Net assets	$ 207,555	$ 225,019
Qualifying assets as percentage of total assets	70%	70%
Non-qualifying assets as percentage of total assets	22.50%	24.70%
Commitment to fund equity investment	$ 61	$ 183
V10 Entertainment, Inc.
CONSOLIDATED SCHEDULE OF INVESTMENTS
Commitment to fund equity investment	$ 189
MC Asset Management (Corporate), LLC ("Corporate") | MC Asset Management (Corporate), LLC ("Corporate")
CONSOLIDATED SCHEDULE OF INVESTMENTS
Percentage of equity interest of parent		15.90%	15.90%
MC Asset Management (Industrial), LLC ("Industrial"). | MC Asset Management (Corporate), LLC ("Corporate")
CONSOLIDATED SCHEDULE OF INVESTMENTS
Percentage of equity interest of parent		100%	100%
HFZ Capital Group LLC
CONSOLIDATED SCHEDULE OF INVESTMENTS
Equity contribution		$ 4,758	$ 4,758
Curion Holdings, LLC
CONSOLIDATED SCHEDULE OF INVESTMENTS
Equity contribution		$ 0

Organization and Principal Busi

Organization and Principal Business	9 Months Ended
	Sep. 30, 2023
Organization and Principal Business
Organization and Principal Business	Note 1. Organization and Principal Business Monroe Capital Corporation (together with its subsidiaries, the “Company”) is an externally managed, non-diversified, closed-end management investment company and has elected to be regulated as a business development company (“BDC”) under the Investment Company Act of 1940, as amended (the “1940 Act”). The Company’s investment objective is to maximize the total return to its stockholders in the form of current income and capital appreciation through investment in senior secured, junior secured and unitranche secured (a combination of senior secured and junior secured debt in the same facility in which the Company syndicates a “first out” portion of the loan to an investor and retains a “last out” portion of the loan) debt and, to a lesser extent, unsecured subordinated debt and equity co-investments in preferred and common stock and warrants. The Company is managed by Monroe Capital BDC Advisors, LLC (“MC Advisors”), a registered investment adviser under the Investment Advisers Act of 1940, as amended. In addition, for U.S. federal income tax purposes, the Company has elected to be treated as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”).

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The accompanying consolidated financial statements of the Company and related financial information have been prepared pursuant to the requirements for reporting on Form 10-Q and Articles 6 and 10 of Regulation S-X. The Company has determined it meets the definition of an investment company and follows the accounting and reporting guidance in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 946 – Financial Services – Investment Companies Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Consolidation As permitted under ASC Topic 946, the Company will generally not consolidate its investment in a portfolio company other than an investment company subsidiary or a controlled operating company whose business consists of providing services to the Company. Accordingly, the Company consolidated the results of the Company’s wholly-owned subsidiaries, including Monroe Capital Corporation SBIC, LP (“MRCC SBIC”) (through its dissolution date on March 31, 2022) and its wholly-owned general partner MCC SBIC GP, LLC, and the Company’s wholly-owned taxable subsidiaries (the “Taxable Subsidiaries”) in its consolidated financial statements. The purpose of the Taxable Subsidiaries is to permit the Company to hold equity investments in portfolio companies that are taxed as partnerships for U.S. federal income tax purposes while complying with the “source of income” requirements contained in the RIC tax provisions. The Taxable Subsidiaries are not consolidated with the Company for U.S. federal corporate income tax purposes, and each Taxable Subsidiary is subject to U.S. federal corporate income tax on its taxable income. All intercompany balances and transactions have been eliminated. The Company does not consolidate its non-controlling interest in MRCC Senior Loan Fund I, LLC (“SLF”). See further description of the Company’s investment in SLF in Note 3. Fair Value of Financial Instruments The Company applies fair value to substantially all of its financial instruments in accordance with ASC Topic 820 — Fair Value Measurements and Disclosures ASC Topic 820 requires disclosure of the fair value of financial instruments for which it is practical to estimate such value. The Company believes that the carrying amounts of its other financial instruments such as cash, receivables and payables approximate the fair value of such items due to the short maturity of such instruments. Revenue Recognition The Company’s revenue recognition policies are as follows: Investments and related investment income: Dividend income on preferred equity securities is recorded as dividend income on an accrual basis to the extent that such amounts are payable by the portfolio company and are expected to be collected. Dividend income on common equity securities is recorded on the record date for private portfolio companies. Each distribution received from limited liability company (“LLC”) and limited partnership (“LP”) investments is evaluated to determine if the distribution should be recorded as dividend income or a return of capital. Generally, the Company will not record distributions from equity investments in LLCs and LPs as dividend income unless there are sufficient accumulated tax-basis earnings and profits in the LLC or LP prior to the applicable distribution. Distributions that are classified as a return of capital are recorded as a reduction in the cost basis of the investment. For both the three and nine months ended September 30, 2023, the Company received return of capital distributions from its equity investments of zero. For the three and nine months ended September 30, 2022, the Company received return of capital distributions from its equity investments and its investment in LLC equity in SLF of zero and $290, respectively. The Company has certain investments in its portfolio that contain a payment-in-kind (“PIK”) provision, which represents contractual interest or dividends that are added to the principal balance and recorded as income. The Company stops accruing PIK interest or PIK dividends when it is determined that PIK interest or PIK dividends are no longer collectible. To maintain RIC tax treatment, and to avoid incurring corporate U.S. federal income tax, substantially all of this income must be paid out to stockholders in the form of distributions, even though the Company has not yet collected the cash. Loan origination fees, original issue discount and market discount or premiums are capitalized, and the Company then amortizes such amounts using the effective interest method as interest income over the life of the investment. Unamortized discounts and loan origination fees totaled $4,149 and $4,701 as of September 30, 2023 and December 31, 2022, respectively. Upfront loan origination and closing fees received for the three and nine months ended September 30, 2023 totaled $202 and $1,003, respectively. Upfront loan origination and closing fees received for the three and nine months ended September 30, 2022 totaled $1,126 and $1,871, respectively. Upon prepayment of a loan or debt security, any unamortized premium or discount or loan origination fees are recorded as interest income. The components of the Company’s investment income were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ September 30, ​ 2023 2022 Interest income ​ $ 12,804 ​ $ 12,491 PIK interest income ​ 2,430 ​ 1,240 Dividend income (1) ​ 1,017 ​ 1,051 Fee income (3) ​ (836) ​ 412 Prepayment gain (loss) ​ 29 ​ 495 Accretion of discounts and amortization of premiums ​ 199 ​ 227 Total investment income ​ $ 15,643 ​ $ 15,916 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended ​ ​ September 30, ​ ​ 2023 ​ 2022 Interest income ​ $ 37,553 ​ $ 30,602 PIK interest income 7,193 4,458 Dividend income (2) ​ 3,169 ​ 3,108 Fee income (3) ​ (356) ​ 1,604 Prepayment gain (loss) ​ 378 ​ 758 Accretion of discounts and amortization of premiums ​ 857 ​ 872 Total investment income ​ $ 48,794 ​ $ 41,402 (1) Includes PIK dividends of $117 and $124 , respectively. (2) Includes PIK dividends of $359 and $350 , respectively. (3) Includes the reversal of $1,046 of previously accrued fee income associated with the Company’s former loan investment in IT Global Holding, LLC. Investment transactions are recorded on a trade-date basis. Realized gains or losses on portfolio investments are calculated based upon the difference between the net proceeds from the disposition and the amortized cost basis of the investment, without regard to unrealized gains or losses previously recognized. Realized gains and losses are recorded within net realized gain (loss) on investments on the consolidated statements of operations. Changes in the fair value of investments from the prior period, as determined through the application of the Company’s valuation policy, are included within net change in unrealized gain (loss) on investments on the consolidated statements of operations. Non-accrual: Distributions Distributions to common stockholders are recorded on the applicable record date. The amount, if any, to be distributed to common stockholders is determined by the Board each quarter and is generally based upon the Company’s earnings estimated by management. Net realized capital gains, if any, are generally distributed at least annually. The determination of the tax attributes for the Company’s distributions is made annually, based upon its taxable income for the full year and distributions paid for the full year. Ordinary dividend distributions from a RIC do not qualify for the preferential tax rate on qualified dividend income from domestic corporations and qualified foreign corporations, except to the extent that the RIC received the income in the form of qualifying dividends from domestic corporations and qualified foreign corporations. The tax attributes for distributions will generally include both ordinary income and capital gains, but may also include qualified dividends or return of capital. In October 2012, the Company adopted a dividend reinvestment plan (“DRIP”) that provides for the reinvestment of dividends on behalf of its stockholders, unless a stockholder has elected to receive dividends in cash. When the Company declares a cash dividend, the Company’s stockholders who have not “opted out” of the DRIP at least three days prior to the dividend payment date will have their cash dividend automatically reinvested into additional shares of the Company’s common stock. The Company has the option to satisfy the share requirements of the DRIP through the issuance of new shares of common stock or through open market purchases of common stock by the DRIP plan administrator. Newly issued shares are valued based upon the final closing price of the Company’s common stock on a date determined by the Board. Shares purchased in the open market to satisfy the DRIP requirements will be valued based upon the average price of the applicable shares purchased by the DRIP plan administrator, before any associated brokerage or other costs. See Note 9 for additional information on the Company’s distributions. Segments In accordance with ASC Topic 280 — Segment Reporting Cash The Company deposits its cash in a financial institution and, at times, such balances may be in excess of the Federal Deposit Insurance Corporation insurance limits. Unamortized Deferred Financing Costs Deferred financing costs represent fees and other direct incremental costs incurred in connection with the Company’s borrowings. As of September 30, 2023 and December 31, 2022, the Company had unamortized deferred financing costs of $3,566 and $4,486 respectively, presented as a direct reduction of the carrying amount of debt on the consolidated statements of assets and liabilities. These amounts are amortized and included in interest and other debt financing expenses on the consolidated statements of operations over the estimated average life of the borrowings. Amortization of deferred financing costs for the three and nine months ended September 30, 2023 was $330 and $977, respectively. Amortization of deferred financing costs for the three and nine months ended September 30, 2022 was $522 and $1,613, respectively. Offering Costs Offering costs include, among other things, fees paid in relation to legal, accounting, regulatory and printing work completed in preparation of debt and equity offerings. Offering costs from equity offerings are charged against the proceeds from the offering within the consolidated statements of changes in net assets. Offering costs from debt offerings are reclassified to unamortized deferred financing costs on the consolidated statements of assets and liabilities as noted above. As of September 30, 2023 and December 31, 2022, other assets on the consolidated statements of assets and liabilities included $262 and $184, respectively, of deferred offering costs, which will be charged against the proceeds from future debt or equity offerings when completed. Investments Denominated in Foreign Currency As of September 30, 2023, the Company held no investments denominated in a foreign currency. As of December 31, 2022, the Company held investments in one portfolio company that was denominated in Australian dollars. At each balance sheet date, portfolio company investments denominated in foreign currencies are translated into U.S. dollars using the spot exchange rate on the last business day of the period. Purchases and sales of foreign portfolio company investments, and any income from such investments, are translated into U.S. dollars using the rates of exchange prevailing on the respective dates of such transactions. Although the fair values of foreign portfolio company investments and the fluctuation in such fair values are translated into U.S. dollars using the applicable foreign exchange rates described above, the Company does not isolate the portion of the change in fair value resulting from foreign currency exchange rates fluctuations from the change in fair value of the underlying investment. All fluctuations in fair value are included in net change in unrealized gain (loss) on investments on the Company’s consolidated statements of operations. Investments denominated in foreign currencies and foreign currency transactions may involve certain consideration and risks not typically associated with those of domestic origin, including unanticipated movements in the value of the foreign currency relative to the U.S. dollar. Derivative Instruments The Company may enter into foreign currency forward contracts to reduce the Company’s exposure to foreign currency exchange rate fluctuations. In a foreign currency forward contract, the Company agrees to receive or deliver a fixed quantity of one currency for another, at a pre-determined price at a future date. Foreign currency forward contracts are marked-to-market based on the difference between the forward rate and the exchange rate at the current period end. Unrealized gain (loss) on foreign currency forward contracts is recorded on the Company’s consolidated statements of assets and liabilities by counterparty on a net basis. The Company does not utilize hedge accounting and as such values its foreign currency forward contracts at fair value with the change in unrealized gain or loss recorded in net change in unrealized gain (loss) on foreign currency forward contracts and the realized gain or loss recorded in net realized gain (loss) on foreign currency forward contracts on the Company’s consolidated statements of operations. Income Taxes The Company has elected to be treated as a RIC under Subchapter M of the Code and operates in a manner so as to qualify for the tax treatment available to RICs. To maintain qualification as a RIC, the Company must, among other things, meet certain source-of-income and asset diversification requirements and distribute to stockholders, for each taxable year, at least 90% of the Company’s “investment company taxable income,” which is generally the Company’s net ordinary income plus the excess, if any, of realized net short-term capital gains over realized net long-term capital losses. If the Company qualifies as a RIC and satisfies the annual distribution requirement, the Company will not have to pay corporate-level federal income taxes on any income that the Company distributes to its stockholders. The Company intends to make distributions in an amount sufficient to maintain RIC status each year and to avoid any federal income taxes on income. The Company is also subject to nondeductible federal excise taxes if the Company does not distribute at least 98% of net ordinary income, 98.2% of any capital gain net income, if any, and any recognized and undistributed income from prior years for which it paid no federal income taxes. To the extent that the Company determines that its estimated current year annual taxable income may exceed estimated current year dividend distributions, the Company accrues excise tax, calculated as 4% of the estimated excess taxable income, if any, as taxable income is earned. For the three and nine months ended September 30, 2023, the Company recorded a net expense (benefit) on the consolidated statements of operations of $95 and $345, respectively, for U.S. federal excise tax. For the three and nine months ended September 30, 2022, the Company recorded a net expense (benefit) on the consolidated statements of operations of ($55) and $64, respectively, for U.S. federal excise tax. As of September 30, 2023 and December 31, 2022, the Company had payables for excise taxes of $106 and $1, respectively, which were included in other assets and accounts payable and accrued expenses, respectively, on the Company’s consolidated statements of assets and liabilities. The Company’s consolidated Taxable Subsidiaries may be subject to U.S. federal and state corporate-level income taxes. For the three and nine months ended September 30, 2023, the Company recorded a net tax expense of zero and $150 on the consolidated statements of operations for these subsidiaries. For the three and nine months ended September 30, 2022, the Company recorded a net tax expense of $923 and $1,225 on the consolidated statements of operations for these subsidiaries. As of both September 30, 2023 and December 31, 2022, the Company did not have any payables for corporate-level income taxes. The Company accounts for income taxes in conformity with ASC Topic 740 — Income Taxes Subsequent Events The Company has evaluated the need for disclosures and/or adjustments resulting from subsequent events through the date the consolidated financial statements were issued. There have been no subsequent events that occurred during such period that would require disclosure in this Form 10-Q or would be required to be recognized in the consolidated financial statements as of and for the nine months ended September 30, 2023. Recent Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform

Investments

Investments	9 Months Ended
	Sep. 30, 2023
Investments
Investments	Note 3. Investments The following tables show the composition of the Company’s investment portfolio, at amortized cost and fair value (with corresponding percentage of total portfolio investments): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 December 31, 2022 Amortized Cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior secured loans $ 419,994 78.2 % $ 436,066 75.3 % Unitranche secured loans ​ 13,522 2.5 ​ 45,352 7.8 ​ Junior secured loans ​ 29,215 5.4 ​ 21,141 3.6 ​ LLC equity interest in SLF ​ 42,650 8.0 ​ 42,650 7.4 ​ Equity securities ​ 31,414 5.9 ​ 34,098 5.9 ​ Total ​ $ 536,795 100.0 % $ 579,307 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Fair Value: ​ ​ ​ Senior secured loans ​ $ 416,316 80.3 % $ 434,023 80.2 % Unitranche secured loans ​ 13,548 2.6 ​ 20,633 3.8 ​ Junior secured loans ​ 27,425 5.3 ​ 22,193 4.1 ​ LLC equity interest in SLF ​ 33,269 6.4 ​ 35,509 6.6 ​ Equity securities ​ 27,726 5.4 ​ 28,682 5.3 ​ Total ​ $ 518,284 100.0 % $ 541,040 100.0 % ​ The following tables show the composition of the Company’s investment portfolio by geographic region, at amortized cost and fair value (with corresponding percentage of total portfolio investments). The geographic composition is determined by the location of the corporate headquarters of the portfolio company, which may not be indicative of the primary source of the portfolio company’s business: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Amortized Cost: ​ ​ ​ International ​ $ — 0.0 % $ 11,860 2.1 % Midwest ​ 163,145 30.4 ​ 157,558 27.2 ​ Northeast ​ 106,674 19.9 ​ 100,961 17.4 ​ Southeast ​ 158,568 29.5 ​ 158,548 27.4 ​ Southwest ​ 25,008 4.7 ​ 27,348 4.7 ​ West ​ 83,400 15.5 ​ 123,032 21.2 ​ Total ​ $ 536,795 100.0 % $ 579,307 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Fair Value: ​ ​ ​ International ​ $ — 0.0 % $ 10,405 1.9 % Midwest ​ 141,810 27.4 ​ 143,691 26.6 ​ Northeast ​ 109,509 21.1 ​ 104,157 19.2 ​ Southeast ​ 154,441 29.8 ​ 155,624 28.8 ​ Southwest ​ 25,931 5.0 ​ 28,287 5.2 ​ West ​ 86,593 16.7 ​ 98,876 18.3 ​ Total ​ $ 518,284 100.0 % $ 541,040 100.0 % ​ The following tables show the composition of the Company’s investment portfolio by industry, at amortized cost and fair value (with corresponding percentage of total portfolio investments): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 December 31, 2022 Amortized Cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense $ 7,601 1.4 % $ 7,461 1.3 % Automotive ​ 17,781 3.3 ​ 16,775 2.9 ​ Banking ​ 17,031 3.2 ​ 17,790 3.1 ​ Beverage, Food & Tobacco ​ 9,924 1.9 ​ 15,625 2.7 ​ Capital Equipment ​ 18,442 3.4 ​ 18,615 3.2 ​ Chemicals, Plastics & Rubber ​ 2,917 0.5 ​ 2,924 0.5 ​ Construction & Building ​ 8,698 1.6 ​ 6,642 1.1 ​ Consumer Goods: Durable ​ 8,792 1.6 ​ 9,333 1.6 ​ Consumer Goods: Non-Durable ​ 3,415 0.6 ​ 28,276 4.9 ​ Environmental Industries ​ 5,434 1.0 ​ 6,164 1.1 ​ FIRE: Finance ​ 14,585 2.7 ​ 25,021 4.3 ​ FIRE: Real Estate ​ 86,633 16.1 ​ 81,922 14.1 ​ Healthcare & Pharmaceuticals ​ 67,025 12.5 ​ 59,659 10.3 ​ High Tech Industries ​ 41,358 7.7 ​ 52,385 9.0 ​ Hotels, Gaming & Leisure ​ 111 0.0 ​ 2,702 0.5 ​ Investment Funds & Vehicles ​ 42,650 8.0 ​ 42,650 7.4 ​ Media: Advertising, Printing & Publishing ​ 18,241 3.4 ​ 17,470 3.0 ​ Media: Broadcasting & Subscription ​ 3,984 0.7 ​ 2,747 0.5 ​ Media: Diversified & Production ​ 41,260 7.7 ​ 36,018 6.2 ​ Retail ​ 2,422 0.5 ​ 9,247 1.6 ​ Services: Business ​ 56,224 10.5 ​ 56,249 9.7 ​ Services: Consumer ​ 39,028 7.3 ​ 40,086 6.9 ​ Telecommunications ​ 7,246 1.4 ​ 7,502 1.3 ​ Wholesale ​ 15,993 3.0 ​ 16,044 2.8 ​ Total ​ $ 536,795 100.0 % $ 579,307 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Fair Value: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense $ 7,578 1.4 % $ 7,436 1.4 % Automotive ​ 16,626 3.2 ​ 16,637 3.1 ​ Banking ​ 16,436 3.2 ​ 19,817 3.7 ​ Beverage, Food & Tobacco ​ 11,434 2.2 ​ 12,470 2.3 ​ Capital Equipment ​ 18,936 3.6 ​ 19,012 3.5 ​ Chemicals, Plastics & Rubber ​ 3,996 0.8 ​ 4,445 0.8 ​ Construction & Building ​ 8,800 1.7 ​ 6,706 1.2 ​ Consumer Goods: Durable ​ 8,739 1.7 ​ 9,338 1.7 ​ Consumer Goods: Non-Durable ​ 3,023 0.6 ​ 3,508 0.6 ​ Environmental Industries ​ 5,895 1.1 ​ 6,558 1.2 ​ FIRE: Finance ​ 15,037 2.9 ​ 23,892 4.4 ​ FIRE: Real Estate ​ 85,387 16.5 ​ 82,498 15.2 ​ Healthcare & Pharmaceuticals ​ 66,309 12.8 ​ 59,273 11.0 ​ High Tech Industries ​ 40,164 7.7 ​ 52,891 9.8 ​ Hotels, Gaming & Leisure ​ 115 0.0 ​ 2,720 0.5 ​ Investment Funds & Vehicles ​ 33,269 6.4 ​ 35,509 6.6 ​ Media: Advertising, Printing & Publishing ​ 20,497 4.0 ​ 19,777 3.7 ​ Media: Broadcasting & Subscription ​ 2,763 0.5 ​ 2,691 0.5 ​ Media: Diversified & Production ​ 41,435 8.0 ​ 36,164 6.7 ​ Retail ​ 1,985 0.4 ​ 9,306 1.7 ​ Services: Business ​ 57,316 11.1 ​ 57,308 10.6 ​ Services: Consumer ​ 30,398 5.9 ​ 31,324 5.8 ​ Telecommunications ​ 7,356 1.4 ​ 7,595 1.4 ​ Wholesale ​ 14,790 2.9 ​ 14,165 2.6 ​ Total ​ $ 518,284 100.0 % $ 541,040 100.0 % ​ MRCC Senior Loan Fund I, LLC The Company co-invests with Life Insurance Company of the Southwest (“LSW”) in senior secured loans through SLF, an unconsolidated Delaware LLC. SLF is capitalized as underlying investment transactions are completed, taking into account available debt and equity commitments available for funding these investments. All portfolio and investment decisions in respect to SLF must be approved by the SLF investment committee, consisting of one representative from the Company and one representative from LSW. SLF may cease making new investments upon notification of either member but operations will continue until all investments have been sold or paid-off in the normal course of business. Investments held by SLF are measured at fair value using the same valuation methodologies as described in Note 4. The Company’s investment is illiquid in nature as SLF does not allow for withdrawal from the LLC or the sale of a member’s interest unless approved by the board members of SLF. The full withdrawal of a member would result in an orderly wind-down of SLF. SLF’s profits and losses are allocated to the Company and LSW in accordance with their respective ownership interests. As of both September 30, 2023 and December 31, 2022, the Company and LSW each owned 50.0% of the LLC equity interests of SLF. As of both September 30, 2023 and December 31, 2022, SLF had $100,000 in equity commitments from its members (in the aggregate), of which $85,300 was funded. As of both September 30, 2023 and December 31, 2022, the Company had committed to fund $50,000 of LLC equity interest subscriptions to SLF. As of both September 30, 2023 and December 31, 2022, $42,650 of the Company’s LLC equity interest subscriptions to SLF had been called and contributed, net of return of capital distributions subject to recall. For the three and nine months ended September 30, 2023 and 2022, the Company received $900 and $2,700 of dividend income from its LLC equity interest in SLF, respectively. SLF has a senior secured revolving credit facility (as amended, the “SLF Credit Facility”) with Capital One, N.A., through its wholly-owned subsidiary MRCC Senior Loan Fund I Financing SPV, LLC (“SLF SPV”). The SLF Credit Facility allows SLF SPV to borrow up to $110,000 (reduced from $175,000 on June 9, 2023), subject to leverage and borrowing base restrictions. Borrowings on the SLF Credit Facility bear interest at an annual rate of LIBOR (three-month) plus 2.10% and the SLF Credit Facility has a maturity date of November 23, 2031. SLF does not pay any fees to MC Advisors or its affiliates; however, SLF has entered into an administration agreement with Monroe Capital Management Advisors, LLC (“MC Management”), pursuant to which certain loan servicing and administrative functions are delegated to MC Management. SLF may reimburse MC Management for its allocable share of overhead and other expenses incurred by MC Management. For the three and nine months ended September 30, 2023, SLF incurred $45 and $154 of allocable expenses, respectively. For the three and nine months ended September 30, 2022, SLF incurred $65 and $175 of allocable expenses, respectively. There are no agreements or understandings by which the Company guarantees any SLF obligations. As of September 30, 2023 and December 31, 2022, SLF had total assets at fair value of $158,667 and $192,830, respectively. As of September 30, 2023 and December 31, 2022, SLF had four and one portfolio company investments on non-accrual status with a fair value of $5,397 and $415, respectively. The portfolio companies in SLF are in industries and geographies similar to those in which the Company may invest directly. Additionally, as of September 30, 2023 and December 31, 2022, SLF had $3,720 and $4,579, respectively, in outstanding commitments to fund investments under undrawn revolvers and delayed draw commitments. Below is a summary of SLF’s portfolio, followed by a listing of the individual investments in SLF’s portfolio as of September 30, 2023 and December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ September 30, 2023 ​ December 31, 2022 Senior secured loans (1) 166,639 197,867 ​ Weighted average current interest rate on senior secured loans (2) 9.7 % 9.7 % Number of portfolio company investments in SLF 53 60 ​ Largest portfolio company investment (1) 6,597 6,650 ​ Total of five largest portfolio company investments (1) 26,900 27,026 ​ (1) Represents outstanding principal amount, excluding unfunded commitments. (2) Computed as the (a) annual stated interest rate on accruing senior secured loans divided by (b) total senior secured loans at outstanding principal amount. ​ MRCC SENIOR LOAN FUND I, LLC CONSOLIDATED SCHEDULE OF INVESTMENTS (unaudited) September 30, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest ​ ​ ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) Index (b) Spread (b) Rate (b) Maturity ​ Principal Fair Value Non-Controlled/Non-Affiliate Company Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Secured Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bromford Industries Limited (c) ​ P ​ 5.25 % 13.75 % (e) ​ 11/5/2025 ​ ​ ​ 2,744 ​ $ 971 Bromford Industries Limited (c) ​ P ​ 5.25 % 13.75 % (e) ​ 11/5/2025 ​ ​ ​ 1,829 ​ ​ 648 Trident Maritime Systems, Inc. ​ SF ​ 5.60 % 10.99 % ​ 2/26/2027 ​ ​ ​ 2,422 ​ ​ 2,399 Trident Maritime Systems, Inc. ​ SF ​ 5.60 % 10.99 % ​ 2/26/2027 ​ ​ ​ 746 ​ ​ 739 Trident Maritime Systems, Inc. (Revolver) ​ SF ​ 5.60 % 10.92 % ​ 2/26/2027 ​ ​ ​ 319 ​ ​ 316 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8,060 ​ ​ 5,073 Automotive ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accelerate Auto Works Intermediate, LLC ​ SF ​ 5.15 % 10.57 % ​ 12/1/2027 ​ ​ ​ 1,358 ​ ​ 1,344 Accelerate Auto Works Intermediate, LLC (Delayed Draw) (d) ​ SF ​ 5.15 % 10.57 % ​ 12/1/2027 ​ ​ ​ 388 ​ ​ — Accelerate Auto Works Intermediate, LLC (Revolver) (d) ​ SF ​ 5.15 % 10.57 % ​ 12/1/2027 ​ ​ ​ 132 ​ ​ — Truck-Lite Co., LLC ​ SF ​ 6.25 % 11.69 % ​ 12/14/2026 ​ ​ ​ 1,678 ​ ​ 1,678 Truck-Lite Co., LLC ​ SF ​ 6.25 % 11.69 % ​ 12/14/2026 ​ ​ ​ 249 ​ ​ 249 Truck-Lite Co., LLC ​ SF ​ 6.25 % 11.69 % ​ 12/14/2026 ​ ​ ​ 43 ​ ​ 43 Wheel Pros, Inc. (f) ​ SF ​ 4.61 % 9.94 % ​ 5/11/2028 ​ ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 3,848 ​ ​ 3,314 Beverage, Food & Tobacco ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SW Ingredients Holdings, LLC ​ SF ​ 4.75 % 10.17 % ​ 7/3/2025 ​ ​ ​ 3,553 ​ ​ 3,551 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 3,553 ​ ​ 3,551 Capital Equipment ​ ​ ​ ​ ​ ​ ​ DS Parent, Inc. ​ SF ​ 5.75 % 11.34 % ​ 12/8/2028 ​ ​ ​ 2,738 ​ ​ 2,714 MacQueen Equipment, LLC ​ SF ​ 5.51 % 10.90 % ​ 1/7/2028 ​ ​ ​ 2,080 ​ ​ 2,080 MacQueen Equipment, LLC (Delayed Draw) (d) ​ SF ​ 5.51 % 10.90 % ​ 1/7/2028 ​ ​ ​ 591 ​ ​ 78 MacQueen Equipment, LLC (Revolver) (d) SF 5.51 % 10.90 % ​ 1/7/2028 ​ ​ 296 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,705 ​ ​ 4,872 Chemicals, Plastics & Rubber ​ ​ ​ ​ ​ ​ Phoenix Chemical Holding Company LLC SF ​ 7.11 % 12.43 % ​ 8/2/2024 ​ ​ 1,131 ​ 1,030 TJC Spartech Acquisition Corp. ​ SF ​ 4.75 % 10.05 % ​ 5/5/2028 ​ ​ ​ 4,221 ​ ​ 3,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,352 ​ ​ 4,829 Construction & Building ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Cook & Boardman Group LLC SF ​ 5.85 % 11.18 % ​ 10/20/2025 ​ ​ 2,857 ​ 2,785 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,857 ​ ​ 2,785 Consumer Goods: Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Elevate Textiles, Inc. (fka International Textile Group, Inc.) SF ​ 6.65 % 11.89 % (e) ​ 9/30/2027 ​ ​ 800 ​ 800 Runner Buyer INC. SF ​ 5.61 % 11.04 % ​ 10/23/2028 ​ ​ 2,955 ​ 2,352 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 3,755 ​ ​ 3,152 Consumer Goods: Non-Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PH Beauty Holdings III, INC. SF ​ 5.00 % 10.68 % ​ 9/26/2025 ​ ​ 2,374 ​ 2,018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,374 ​ ​ 2,018 Containers, Packaging & Glass ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Polychem Acquisition, LLC SF ​ 5.11 % 10.43 % ​ 3/17/2025 ​ ​ 2,865 ​ 2,865 PVHC Holding Corp ​ SF ​ 5.65 % 11.04 % Cash/ % PIK ​ 2/17/2027 ​ ​ 1,897 ​ 1,830 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,762 ​ 4,695 Energy: Oil & Gas ​ ​ ​ ​ ​ Drilling Info Holdings, Inc. SF 4.35 % 9.67 % ​ 7/30/2025 ​ ​ 4,434 ​ 4,299 Offen, Inc. SF 5.43 % 10.46 % ​ 6/22/2026 ​ ​ 2,249 ​ 2,249 Offen, Inc. SF 5.43 % 10.46 % ​ 6/22/2026 ​ ​ 861 ​ 861 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,544 ​ ​ 7,409 FIRE: Finance ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Harbour Benefit Holdings, Inc. ​ SF ​ 5.15 % 10.54 % ​ 12/13/2024 ​ ​ ​ 2,865 ​ ​ 2,865 Harbour Benefit Holdings, Inc. ​ SF ​ 5.10 % 10.42 % ​ 12/13/2024 ​ ​ ​ 61 ​ ​ 61 Minotaur Acquisition, Inc. ​ SF ​ 4.85 % 10.17 % ​ 3/27/2026 ​ ​ ​ 4,819 ​ ​ 4,808 TEAM Public Choices, LLC ​ SF ​ 5.43 % 10.88 % ​ 12/17/2027 ​ ​ ​ 2,932 ​ ​ 2,890 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,677 ​ ​ 10,624 FIRE: Real Estate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Avison Young (USA) Inc. (c) ​ SF ​ 6.76 % 12.15 % (e) ​ 1/30/2026 ​ ​ ​ 4,775 ​ ​ 1,892 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,775 ​ ​ 1,892 ​ ​ MRCC SENIOR LOAN FUND I, LLC CONSOLIDATED SCHEDULE OF INVESTMENTS - (continued) (unaudited) September 30, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) Index (b) Spread (b) Rate (b) Maturity Principal Fair Value Healthcare & Pharmaceuticals ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cano Health, LLC ​ SF ​ 4.10 % 9.42 % ​ 11/23/2027 ​ 1,955 ​ $ 1,272 HAH Group Holding Company LLC ​ SF ​ 5.00 % 10.42 % ​ 10/29/2027 ​ 2,958 ​ ​ 2,928 LSCS Holdings, Inc. ​ SF ​ 4.61 % 9.93 % ​ 12/15/2028 ​ 1,814 ​ ​ 1,792 Natus Medical Incorporated ​ SF ​ 5.50 % 11.04 % ​ 7/20/2029 ​ 4,962 ​ ​ 4,665 Paragon Healthcare, Inc. ​ SF ​ 5.85 % 11.17 % ​ 1/19/2027 ​ 2,111 ​ ​ 2,081 Paragon Healthcare, Inc. ​ SF ​ 5.75 % 11.12 % ​ 1/19/2027 ​ 364 ​ ​ 359 Paragon Healthcare, Inc. (Revolver) (d) ​ SF ​ 5.75 % 11.12 % ​ 1/19/2027 ​ 490 ​ ​ — Radiology Partners, Inc. ​ SF ​ 4.68 % 10.18 % ​ 7/9/2025 ​ 4,750 ​ ​ 3,599 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 19,404 ​ ​ 16,696 High Tech Industries ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corel Inc. (c) ​ SF ​ 5.10 % 10.52 % ​ 7/2/2026 ​ 3,450 ​ ​ 3,324 Lightbox Intermediate, L.P. ​ SF ​ 5.26 % 10.65 % ​ 5/11/2026 ​ 4,788 ​ ​ 4,644 TGG TS Acquisition Company ​ SF ​ 6.61 % 11.93 % ​ 12/12/2025 ​ 2,946 ​ ​ 2,886 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 11,184 ​ 10,854 Hotels, Gaming & Leisure ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Excel Fitness Holdings, Inc. ​ SF ​ 5.40 % 10.79 % ​ 4/27/2029 ​ 4,331 ​ ​ 4,108 Excel Fitness Holdings, Inc. (Revolver) (d) ​ SF ​ 5.40 % 10.79 % ​ 4/28/2028 ​ 625 ​ ​ — North Haven Spartan US Holdco, LLC ​ SF ​ 6.25 % 11.65 % ​ 6/6/2025 ​ 2,256 ​ ​ 2,242 Tait LLC ​ SF ​ 5.00 % 10.25 % ​ 3/28/2025 ​ 4,051 ​ ​ 4,027 Tait LLC (Revolver) (d) ​ SF ​ 5.00 % 10.25 % ​ 3/28/2025 ​ 769 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 12,032 ​ ​ 10,377 Media: Diversified & Production ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Research Now Group, Inc. and Survey Sampling International, LLC ​ SF ​ 5.76 % 11.13 % ​ 12/20/2024 ​ 6,597 ​ ​ 4,823 STATS Intermediate Holdings, LLC ​ SF ​ 5.51 % 10.89 % ​ 7/10/2026 ​ 4,813 ​ ​ 4,548 TA TT Buyer, LLC ​ SF ​ 5.00 % 10.39 % ​ 3/30/2029 ​ 3,300 ​ ​ 3,297 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 14,710 ​ ​ 12,668 Services: Business ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CHA Holdings, Inc ​ SF ​ 4.76 % 10.15 % ​ 4/10/2025 ​ 1,944 ​ ​ 1,913 CHA Holdings, Inc ​ SF ​ 4.76 % 10.15 % ​ 4/10/2025 ​ 410 ​ ​ 403 Eliassen Group, LLC ​ SF ​ 5.50 % 10.84 % ​ 4/14/2028 ​ 3,227 ​ ​ 3,173 Eliassen Group, LLC (Delayed Draw) (d) ​ SF ​ 5.50 % 10.82 % ​ 4/14/2028 ​ 740 ​ ​ 228 Engage2Excel, Inc. ​ SF ​ 7.35 % 12.21 % ​ 12/31/2023 ​ 4,282 ​ ​ 4,270 Engage2Excel, Inc. ​ SF ​ 7.35 % 12.21 % ​ 12/31/2023 ​ 773 ​ ​ 771 Engage2Excel, Inc. (Revolver) ​ SF ​ 7.35 % 12.69 % ​ 12/31/2023 ​ 550 ​ ​ 550 ​ ​ ​ ​ ​ ​ 10.82 % Cash/ ​ ​ ​ ​ ​ ​ ​ Output Services Group, Inc. ​ SF ​ 5.25 % 1.50 % PIK (e) ​ 6/29/2026 ​ 4,812 ​ ​ 1,011 Secretariat Advisors LLC ​ SF ​ 5.01 % 10.40 % ​ 12/29/2028 ​ 1,680 ​ ​ 1,663 Secretariat Advisors LLC ​ SF ​ 5.01 % 10.40 % ​ 12/29/2028 ​ 268 ​ ​ 265 SIRVA Worldwide Inc. ​ SF ​ 5.61 % 10.93 % ​ 8/4/2025 ​ 1,763 ​ ​ 1,589 Teneo Holdings LLC ​ SF ​ 5.35 % 10.67 % ​ 7/11/2025 ​ 4,800 ​ ​ 4,809 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 25,249 ​ ​ 20,645 Services: Consumer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 360Holdco, Inc. ​ SF ​ 5.60 % 10.92 % ​ 8/1/2025 ​ 2,130 ​ ​ 2,130 360Holdco, Inc. ​ SF ​ 5.60 % 10.92 % ​ 8/1/2025 ​ 823 ​ ​ 823 Laseraway Intermediate Holdings II, LLC ​ SF ​ 5.75 % 11.32 % ​ 10/14/2027 ​ 2,183 ​ ​ 2,153 McKissock Investment Holdings, LLC ​ SF ​ 5.00 % 10.43 % ​ 3/9/2029 ​ 2,463 ​ ​ 2,435 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,599 ​ ​ 7,541 Telecommunications ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Intermedia Holdings, Inc. ​ SF ​ 6.11 % 11.43 % ​ 7/21/2025 ​ 1,746 ​ ​ 1,665 Mavenir Systems, Inc. ​ SF ​ 5.11 % 10.49 % ​ 8/18/2028 ​ 1,642 ​ ​ 1,310 Sandvine Corporation ​ SF ​ 4.50 % 9.82 % ​ 10/31/2025 ​ 1,973 ​ ​ 1,699 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,361 ​ ​ 4,674 Transportation: Cargo ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Keystone Purchaser, LLC ​ SF ​ 5.75 % 10.96 % ​ 5/7/2027 ​ 4,917 ​ ​ 4,880 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,917 ​ ​ 4,880 Utilities: Oil & Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Dresser Utility Solutions, LLC ​ SF ​ 4.10 % 9.42 % ​ 10/1/2025 ​ 1,664 ​ ​ 1,631 Dresser Utility Solutions, LLC ​ SF ​ 5.35 % 10.67 % ​ 10/1/2025 ​ 243 ​ ​ 239 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1,907 ​ ​ 1,870 Wholesale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HALO Buyer, Inc. ​ SF ​ 4.60 % 9.92 % ​ 6/30/2025 ​ 4,736 ​ ​ 3,658 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,736 ​ ​ 3,658 Total Non-Controlled/Non-Affiliate Senior Secured Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 170,361 ​ $ 148,077 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity Securities (g) (h) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Consumer Goods: Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Elevate Textiles, Inc. (fka International Textile Group, Inc.) (25,524 shares of common units) ​ — ​ — ​ — (i) ​ — ​ — ​ ​ 75 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 75 Chemicals, Plastics & Rubber ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Polyventive Lender Holding Company LLC (0.84% of the equity) ​ — ​ — ​ — (i) ​ — ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ — Total Non-Controlled/Non-Affiliate Equities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 75 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TOTAL INVESTMENTS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 148,152 (a) All investments are U.S. companies unless otherwise noted. (b) The majority of investments bear interest at a rate that may be determined by reference to the London Interbank Offered Rate (“LIBOR” or “L”), Secured Overnight Financing Rate (“SOFR” or “SF”) or Prime (“P”) which reset daily, monthly, quarterly or semiannually. The Company has provided the spread over LIBOR, SOFR or Prime and the current contractual rate of interest in effect at September 30, 2023. Certain investments may be subject to an interest rate floor or cap. Certain investments contain a PIK provision. (c) This is an international company. (d) All or a portion of this commitment was unfunded as of September 30, 2023. As such, interest is earned only on the funded portion of this commitment. Principal reflects the commitment outstanding. (e) This position was on non-accrual status as of September 30, 2023, meaning that we have ceased accruing interest income on the position. (f) Investment position or portion thereof unsettled at September 30, 2023. (g) Represents less than 5% ownership of the portfolio company’s voting securities. (h) Ownership of certain equity investments may occur through a holding company partnership. (i) Represents a non-income producing security. ​ ​ ​ MRCC SENIOR LOAN FUND I, LLC CONSOLIDATED SCHEDULE OF INVESTMENTS December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) ​ Index (b) ​ Spread (b) ​ Interest Rate (b) ​ Maturity ​ Principal ​ Fair Value Non-Controlled/Non-Affiliate Company Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Secured Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bromford Industries Limited (c) ​ P ​ 5.25 % ​ 12.75 % ​ 11/5/2025 ​ 2,744 ​ $ 2,581 Bromford Industries Limited (c) ​ P ​ 5.25 % ​ 12.75 % ​ 11/5/2025 ​ 1,829 ​ ​ 1,720 Trident Maritime Systems, Inc. ​ L ​ 4.75 % ​ 9.48 % ​ 2/26/2027 ​ 2,445 ​ ​ 2,443 Trident Maritime Systems, Inc. ​ L ​ 4.75 % ​ 9.48 % ​ 2/26/2027 ​ 746 ​ ​ 746 Trident Maritime Systems, Inc. (Revolver) (d) ​ L ​ 4.75 % ​ 9.08 % ​ 2/26/2027 ​ 319 ​ ​ 122 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8,083 ​ ​ 7,612 Automotive ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accelerate Auto Works Intermediate, LLC ​ L ​ 4.50 % ​ 9.23 % ​ 12/1/2027 ​ 1,391 ​ ​ 1,386 Accelerate Auto Works Intermediate, LLC (Delayed Draw) (d) ​ L ​ 4.50 % ​ 9.23 % ​ 12/1/2027 ​ 388 ​ ​ — Accelerate Auto Works Intermediate, LLC (Revolver) (d) ​ L ​ 4.50 % ​ 9.23 % ​ 12/1/2027 ​ 132 ​ ​ — Truck-Lite Co., LLC ​ SF ​ 6.25 % ​ 11.14 % ​ 12/14/2026 ​ 1,691 ​ ​ 1,690 Truck-Lite Co., LLC ​ SF ​ 6.25 % ​ 11.14 % ​ 12/14/2026 ​ 251 ​ ​ 250 Truck-Lite Co., LLC ​ SF ​ 6.25 % ​ 11.14 % ​ 12/14/2026 ​ 43 ​ ​ 43 Wheel Pros, Inc. ​ L ​ 4.50 % ​ 8.82 % ​ 5/11/2028 ​ 1,932 ​ ​ 1,321 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,828 ​ ​ 4,690 Beverage, Food & Tobacco ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CBC Restaurant Corp. ​ n/a ​ n/a ​ ​ 5.00 % PIK (e) ​ n/a (f) 1,066 ​ ​ 415 SW Ingredients Holdings, LLC ​ L ​ 4.75 % ​ 9.13 % ​ 7/3/2025 ​ 3,581 ​ ​ 3,581 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,647 ​ ​ 3,996 Capital Equipment ​ ​ ​ ​ ​ ​ Analogic Corporation L 5.25 % ​ 9.66 % ​ 6/24/2024 4,703 ​ 4,433 DS Parent, Inc. ​ L ​ 5.75 % ​ 9.92 % ​ 12/8/2028 ​ 2,850 ​ ​ 2,725 MacQueen Equipment, LLC ​ L ​ 5.25 % ​ 9.98 % ​ 1/7/2028 ​ 2,096 ​ ​ 2,096 MacQueen Equipment, LLC (Delayed Draw) (d) ​ L ​ 5.25 % ​ 9.98 % ​ 1/7/2028 ​ 592 ​ ​ 69 MacQueen Equipment, LLC (Revolver) (d) L 5.25 % ​ 9.98 % ​ 1/7/2028 296 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,537 ​ ​ 9,323 Chemicals, Plastics & Rubber ​ ​ ​ ​ ​ Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group) L ​ 7.00 % ​ 11.39 % ​ 6/15/2023 1,139 ​ 1,132 TJC Spartech Acquisition Corp. ​ L ​ 4.75 % ​ 8.53 % ​ 5/5/2028 ​ 4,253 ​ ​ 4,131 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,392 ​ ​ 5,263 Construction & Building ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Cook & Boardman Group LLC SF ​ 5.75 % ​ 9.99 % ​ 10/20/2025 2,879 ​ 2,458 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,879 ​ ​ 2,458 Consumer Goods: Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ International Textile Group, Inc. L ​ 5.00 % ​ 9.21 % ​ 5/1/2024 1,664 ​ 1,166 Runner Buyer INC. L ​ 5.50 % ​ 10.23 % ​ 10/23/2028 2,978 ​ 2,114 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,642 ​ ​ 3,280 Consumer Goods: Non-Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PH Beauty Holdings III, INC. L ​ 5.00 % ​ 9.73 % ​ 9/26/2025 2,393 ​ 1,950 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,393 ​ ​ 1,950 Containers, Packaging & Glass ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liqui-Box Holdings, Inc. L ​ 4.50 % ​ 9.23 % ​ 2/26/2027 4,225 ​ 4,186 Polychem Acquisition, LLC L ​ 5.00 % ​ 9.38 % ​ 3/17/2025 2,888 ​ 2,888 PVHC Holding Corp L 4.75 % ​ 9.48 % ​ 8/5/2024 3,184 ​ 3,072 ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,297 ​ ​ 10,146 Energy: Oil & Gas ​ ​ ​ ​ Drilling Info Holdings, Inc. L 4.25 % ​ 8.63 % ​ 7/30/2025 4,469 ​ 4,313 Offen, Inc. L 5.00 % ​ 9.38 % ​ 6/22/2026 2,249 ​ 2,249 Offen, Inc. L 5.00 % ​ 9.38 % ​ 6/22/2026 867 ​ 867 ​ ​ ​ ​ ​ ​ ​ ​ 7,585 ​ ​ 7,429 ​ ​ MRCC SENIOR LOAN FUND I, LLC CONSOLIDATED SCHEDULE OF INVESTMENTS - (continued) December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) ​ Index (b) ​ Spread (b) ​ Interest Rate (b) ​ Maturity ​ Principal ​ Fair Value FIRE: Finance ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Harbour Benefit Holdings, Inc. ​ L ​ 5.25 % 9.98 % ​ 12/13/2024 ​ 2,901 ​ $ 2,898 Harbour Benefit Holdings, Inc. ​ L ​ 5.25 % 9.63 % ​ 12/13/2024 ​ 61 ​ ​ 61 Minotaur Acquisition, Inc. ​ SF ​ 4.75 % 9.17 % ​ 3/27/2026 ​ 4,857 ​ ​ 4,656 TEAM Public Choices, LLC ​ L ​ 5.00 % 9.93 % ​ 12/17/2027 ​ 2,955 ​ ​ 2,822 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,774 ​ ​ 10,437 FIRE: Real Estate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Avison Young (USA) Inc. (c) ​ SF ​ 5.75 % 10.19 % ​ 1/30/2026 ​ 4,800 ​ ​ 4,020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,800 ​ ​ 4,020 Healthcare & Pharmaceuticals ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cano Health, LLC ​ SF ​ 4.00 % 8.42 % ​ 11/23/2027 ​ 1,970 ​ ​ 1,572 HAH Group Holding Company LLC ​ SF ​ 5.00 % 9.43 % ​ 10/29/2027 ​ 2,978 ​ ​ 2,847 LSCS Holdings, Inc. ​ L ​ 4.50 % 8.88 % ​ 12/15/2028 ​ 1,828 ​ ​ 1,751 Natus Medical Incorporated ​ SF ​ 5.50 % 8.68 % ​ 7/20/2029 ​ 5,000 ​ ​ 4,650 Paragon Healthcare, Inc. ​ SF ​ 5.75 % 9.81 % ​ 1/19/2027 ​ 2,127 ​ ​ 2,109 Paragon Healthcare, Inc. (Delayed Draw) (d) ​ SF ​ 5.75 % 10.06 % ​ 1/19/2027 ​ 366 ​ ​ 242 Paragon Healthcare, Inc. (Revolver) (d) ​ SF ​ 5.75 % 10.26 % ​ 1/19/2027 ​ 490 ​ ​ 61 Radiology Partners, Inc. ​ L ​ 4.25 % 8.64 % ​ 7/9/2025 ​ 4,760 ​ ​ 4,018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 19,519 ​ ​ 17,250 High Tech Industries ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corel Inc. (c) ​ L ​ 5.00 % 9.73 % ​ 7/2/2026 ​ 3,600 ​ ​ 3,365 Lightbox Intermediate, L.P. ​ L ​ 5.00 % 9.73 % ​ 5/11/2026 ​ 4,825 ​ ​ 4,656 TGG TS Acquisition Company ​ L ​ 6.50 % 10.88 % ​ 12/12/2025 ​ 3,190 ​ ​ 3,143 ​ ​ ​ ​ ​ ​ ​ ​ 11,615 ​ ​ 11,164 Hotels, Gaming & Leisure ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Excel Fitness Holdings, Inc. ​ SF ​ 5.25 % 10.29 % ​ 4/27/2029 ​ 4,364 ​ ​ 4,102 Excel Fitness Holdings, Inc. (Revolver) (d) ​ SF ​ 5.25 % 9.67 % ​ 4/28/2028 ​ 625 ​ ​ 306 North Haven Spartan US Holdco, LLC ​ SF ​ 6.25 % 10.71 % ​ 6/6/2025 ​ 2,280 ​ ​ 2,202 Tait LLC ​ L ​ 5.00 % 8.75 % ​ 3/28/2025 ​ 4,083 ​ ​ 3,972 Tait LLC (Revolver) (d) ​ P ​ 4.00 % 10.25 % ​ 3/28/2025 ​ 769 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 12,121 ​ ​ 10,582 Media: Advertising, Printing & Publishing ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cadent, LLC ​ L ​ 6.50 % 11.23 % ​ 9/11/2025 ​ 4,237 ​ ​ 4,131 Cadent, LLC (Revolver) (d) ​ L ​ 6.50 % 11.23 % ​ 9/11/2025 ​ 167 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,404 ​ ​ 4,131 Media: Diversified & Production ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Research Now Group, Inc. and Survey Sampling International, LLC ​ L ​ 5.50 % 8.84 % ​ 12/20/2024 ​ 6,650 ​ ​ 5,035 STATS Intermediate Holdings, LLC ​ L ​ 5.25 % 9.90 % ​ 7/10/2026 ​ 4,850 ​ ​ 4,498 TA TT Buyer, LLC ​ SF ​ 5.00 % 8.98 % ​ 3/30/2029 ​ 3,325 ​ ​ 3,242 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 14,825 ​ ​ 12,775 Services: Business ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ AQ Carver Buyer, Inc. ​ L ​ 5.00 % 9.38 % ​ 9/23/2025 ​ 4,838 ​ ​ 4,834 CHA Holdings, Inc ​ L ​ 4.50 % 9.23 % ​ 4/10/2025 ​ 1,960 ​ ​ 1,886 CHA Holdings, Inc ​ L ​ 4.50 % 9.23 % ​ 4/10/2025 ​ 413 ​ ​ 398 Eliassen Group, LLC ​ SF ​ 5.50 % 10.08 % ​ 4/14/2028 ​ 3,251 ​ ​ 3,194 Eliassen Group, LLC (Delayed Draw) (d) ​ SF ​ 5.50 % 8.88 % ​ 4/14/2028 ​ 740 ​ ​ 109 Engage2Excel, Inc. ​ L ​ 7.25 % 11.98 % ​ 3/7/2023 ​ 4,283 ​ ​ 4,242 Engage2Excel, Inc. ​ L ​ 7.25 % 11.98 % ​ 3/7/2023 ​ 773 ​ ​ 766 Engage2Excel, Inc. (Revolver) (d) ​ P ​ 6.25 % 13.75 % ​ 3/7/2023 ​ 554 ​ ​ 509 Orbit Purchaser LLC ​ L ​ 4.50 % 9.23 % ​ 10/21/2024 ​ 2,406 ​ ​ 2,190 Orbit Purchaser LLC ​ L ​ 4.50 % 9.23 % ​ 10/21/2024 ​ 1,858 ​ ​ 1,691 Orbit Purchaser LLC ​ L ​ 4.50 % 9.23 % ​ 10/21/2024 ​ 543 ​ ​ 494 ​ ​ ​ ​ ​ ​ 9.80 % Cash/ ​ ​ ​ ​ ​ ​ ​ Output Services Group, Inc. ​ SF ​ 6.75 % 1.50 % PIK ​ 6/29/2026 ​ 4,807 ​ ​ 3,275 Secretariat Advisors LLC ​ L ​ 4.75 % 9.48 % ​ 12/29/2028 ​ 1,693 ​ ​ 1,634 Secretariat Advisors LLC ​ L ​ 4.75 % 9.48 % ​ 12/29/2028 ​ 270 ​ ​ 260 SIRVA Worldwide Inc. ​ L ​ 5.50 % 10.23 % ​ 8/4/2025 ​ 1,800 ​ ​ 1,606 Teneo Holdings LLC ​ SF ​ 5.25 % 9.67 % ​ 7/11/2025 ​ 4,837 ​ ​ 4,668 The Kleinfelder Group, Inc. ​ L ​ 5.25 % 9.98 % ​ 11/29/2024 ​ 2,362 ​ ​ 2,362 ​ ​ ​ ​ ​ ​ ​ ​ 37,388 ​ ​ 34,118 Services: Consumer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 360Holdco, Inc. ​ SF ​ 5.00 % 9.42 % ​ 8/2/2025 ​ 2,145 ​ ​ 2,145 360Holdco, Inc. (Delayed Draw) (d) ​ SF ​ 5.00 % 9.42 % ​ 8/2/2025 ​ 827 ​ ​ 252 Laseraway Intermediate Holdings II, LLC ​ L ​ 5.75 % 9.76 % ​ 10/14/2027 ​ 2,200 ​ ​ 2,161 McKissock Investment Holdings, LLC ​ SF ​ 5.00 % 8.87 % ​ 3/9/2029 ​ 2,481 ​ ​ 2,322 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,653 ​ ​ 6,880 Telecommunications ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Intermedia Holdings, Inc. ​ L ​ 6.00 % 10.38 % ​ 7/21/2025 ​ 1,760 ​ ​ 1,360 Mavenir Systems, Inc. ​ L ​ 4.75 % 9.42 % ​ 8/18/2028 ​ 1,654 ​ ​ 1,350 Sandvine Corporation ​ L ​ 4.50 % 8.88 % ​ 10/31/2025 ​ 2,000 ​ ​ 1,904 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,414 ​ ​ 4,614 Transportation: Cargo ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Keystone Purchaser, LLC ​ L ​ 5.50 % 10.60 % ​ 5/7/2027 ​ 4,955 ​ ​ 4,955 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,955 ​ ​ 4,955 Utilities: Oil & Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Dresser Utility Solutions, LLC (fka NGS US Finco, LLC) ​ L ​ 4.25 % 8.63 % ​ 10/1/2025 ​ 1,678 ​ ​ 1,619 Dresser Utility Solutions, LLC (fka NGS US Finco, LLC) ​ L ​ 5.25 % 9.63 % ​ 10/1/2025 ​ 245 ​ ​ 239 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1,923 ​ ​ 1,858 Wholesale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HALO Buyer, Inc. ​ L ​ 4.50 % 8.88 % ​ 6/30/2025 ​ 4,774 ​ ​ 4,219 ​ ​ ​ ​ ​ ​ ​ ​ 4,774 ​ ​ 4,219 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TOTAL INVESTMENTS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 183,150 ​ MRCC SENIOR LOAN FUND I, LLC CONSOLIDATED SCHEDULE OF INVESTMENTS - (continued) December 31, 2022 ​ (a) All investments are U.S. companies unless otherwise noted. (b) The majority of investments bear interest at a rate that may be determined by reference to the London Interbank Offered Rate (“LIBOR” or “L”), Secured Overnight Financing Rate (“SOFR” or “SF”) or Prime (“P”) which reset daily, monthly, quarterly or semiannually. The Company has provided the spread over LIBOR, SOFR or Prime and the current contractual rate of interest in effect at December 31, 2022. Certain investments may be subject to an interest rate floor or cap. Certain investments contain a Payment-in-kind (“PIK”) provision. (c) This is an international company. (d) All or a portion of this commitment was unfunded as of December 31, 2022. As such, interest is earned only on the funded portion of this commitment. Principal reflects the commitment outstanding. (e) This position was on non-accrual status as of December 31, 2022, meaning that the Company has ceased accruing interest income on the position. (f) This is a demand note with no stated maturity. ​ ​ Below is certain summarized financial information for SLF as of September 30, 2023 and December 31, 2022 and for the three and nine months ended September 30, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 December 31, 2022 ​ ​ (unaudited) ​ ​ ​ Assets ​ ​ Investments, at fair value ​ $ 148,152 ​ $ 183,150 Cash ​ 2,104 ​ 1,608 Restricted cash ​ 5,523 ​ 6,454 Interest receivable ​ 1,246 ​ 1,613 Other assets ​ 1,642 ​ 5 Total assets ​ $ 158,667 ​ $ 192,830 Liabilities ​ ​ ​ Revolving credit facility ​ $ 92,064 ​ $ 122,215 Less: Unamortized deferred financing costs ​ (919) ​ (1,518) Total debt, less unamortized deferred financing costs ​ 91,145 ​ 120,697 Interest payable ​ 621 ​ 769 Accounts payable and accrued expenses ​ 363 ​ 346 Total liabilities ​ 92,129 ​ 121,812 Members’ capital ​ 66,538 ​ 71,018 Total liabilities and members’ capital ​ $ 158,667 ​ $ 192,830 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, ​ Nine months ended September 30, ​ 2023 2022 2023 2022 ​ ​ (unaudited) ​ (unaudited) Investment income: ​ ​ ​ ​ Interest income ​ $ 3,936 ​ $ 4,075 ​ $ 14,017 ​ $ 10,593 Total investment income ​ 3,936 ​ 4,075 ​ 14,017 ​ 10,593 Expenses: ​ ​ ​ ​ ​ ​ ​ ​ Interest and other debt financing expenses ​ 2,194 ​ 1,669 ​ 6,848 ​ 3,866 Professional fees ​ 146 ​ 203 ​ 549 ​ 580 Total expenses ​ 2,340 ​ 1,872 ​ 7,397 ​ 4,446 Net investment income (loss) ​ 1,596 ​ 2,203 ​ 6,620 ​ 6,147 Net gain (loss): ​ ​ ​ ​ ​ ​ ​ ​ Net realized gain (loss) on investments ​ ​ (274) ​ ​ — ​ ​ (814) ​ ​ — Net change in unrealized gain (loss) on investments ​ (2,073) ​ (2,416) ​ (4,886) ​ (10,909) Net gain (loss) ​ (2,347) ​ (2,416) ​ (5,700) ​ (10,909) Net increase (decrease) in members’ capital ​ $ (751) ​ $ (213) ​ $ 920 ​ $ (4,762) ​

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Measurements
Fair Value Measurements	Note 4. Fair Value Measurements Investments The Company values all investments in accordance with ASC Topic 820. ASC Topic 820 requires enhanced disclosures about assets and liabilities that are measured and reported at fair value. As defined in ASC Topic 820, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Where available, fair value is based on observable market prices or parameters, or derived from such prices or parameters. Where observable prices or inputs are not available, valuation models are applied. These valuation models involve some level of management estimation and judgment, the degree of which is dependent on the price transparency for the assets or liabilities or market and the assets’ or liabilities’ complexity. ASC Topic 820 establishes a hierarchal disclosure framework which prioritizes and ranks the level of market price observability of inputs used in measuring investments at fair value. Market price observability is affected by a number of factors, including the type of investment and the characteristics specific to the investment. Investments with readily available active quoted prices or for which fair value can be measured from actively quoted prices generally will have a higher degree of market price observability and a lesser degree of judgment used in measuring fair value. Based on the observability of the inputs used in the valuation techniques, the Company is required to provide disclosures on fair value measurements according to the fair value hierarchy. The fair value hierarchy ranks the observability of the inputs used to determine fair values. Investments carried at fair value are classified and disclosed in one of the following three categories: ● Level 1 – Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date. ● Level 2 – Valuations based on inputs other than quoted prices in active markets, including quoted prices for similar assets or liabilities, which are either directly or indirectly observable. ● Level 3 – Valuations based on inputs that are unobservable and significant to the overall fair value measurement. This includes situations where there is little, if any, market activity for the assets or liabilities. The inputs into the determination of fair value are based upon the best information available and may require significant management judgment or estimation. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an asset’s or liability’s categorization within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. For periods prior to September 30, 2022, the Board determined the fair value of the Company’s investments. Pursuant to the new SEC Rule 2a-5 of the 1940 Act, on September 30, 2022 the Board designated MC Advisors as the Company’s valuation designee (the “Valuation Designee”). The Board is responsible for oversight of the Valuation Designee. The Valuation Designee has established a valuation committee to determine in good faith the fair value of the Company’s investments, based on input of the Valuation Designee’s management and personnel and independent valuation firms which are engaged at the direction of the valuation committee to assist in the valuation of certain portfolio investments lacking a readily available market quotation. The valuation committee determines fair values pursuant to a valuation policy approved by the Board and pursuant to a consistently applied valuation process. With respect to investments for which market quotations are not readily available, the Valuation Designee undertakes a multi-step valuation process each quarter, as described below: ● the quarterly valuation process begins with each portfolio company or investment being initially evaluated and rated by the investment professionals of Valuation Designee responsible for the credit monitoring of the portfolio investment; ● the Valuation Designee engages an independent valuation firm to conduct independent appraisals of a selection of investments for which market quotations are not readily available. The Company will consult with an independent valuation firm relative to each portfolio company at least once in every calendar year, but the independent appraisals are generally received quarterly for each investment; ● to the extent an independent valuation firm is not engaged to conduct an investment appraisal on an investment for which market quotations are not readily available, the investment will be valued by the Valuation Designee; ● preliminary valuation conclusions are then documented and discussed with the valuation committee of the Valuation Designee; ● the valuation conclusions are approved by the valuation committee of the Valuation Designee; and ● a report prepared by the Valuation Designee is presented to the Board quarterly to allow the Board to perform its oversight duties of the valuation process and the Valuation Designee. The accompanying consolidated schedules of investments held by the Company consist primarily of private debt instruments (“Level 3 debt”). The Company generally uses the income approach to determine fair value for Level 3 debt where market quotations are not readily available, as long as it is appropriate. If there is deterioration in credit quality or a debt investment is in workout status, the Company may consider other factors in determining the fair value, including the value attributable to the debt investment from the enterprise value of the portfolio company or the proceeds that would be received in a liquidation analysis. This liquidation analysis may include probability weighting of alternative outcomes. The Company generally considers its Level 3 debt to be performing if the borrower is not in default, the borrower is remitting payments in a timely manner; the loan is in covenant compliance or is otherwise not deemed to be impaired. In determining the fair value of the performing Level 3 debt, the Company considers fluctuations in current interest rates, the trends in yields of debt instruments with similar credit ratings, financial condition of the borrower, economic conditions and other relevant factors, both qualitative and quantitative. In the event that a Level 3 debt instrument is not performing, as defined above, the Company will evaluate the value of the collateral utilizing the same framework described above for a performing loan to determine the value of the Level 3 debt instrument. Under the income approach, discounted cash flow models are utilized to determine the present value of the future cash flow streams of its debt investments, based on future interest and principal payments as set forth in the associated loan agreements. In determining fair value under the income approach, the Company also considers the following factors: applicable market yields and leverage levels, credit quality, prepayment penalties, the nature and realizable value of any collateral, the portfolio company’s ability to make payments, and changes in the interest rate environment and the credit markets that generally may affect the price at which similar investments may be made. Under the market approach, the enterprise value methodology is typically utilized to determine the fair value of an investment. There is no one methodology to estimate enterprise value and, in fact, for any one portfolio company, enterprise value is generally best expressed as a range of values, from which the Company derives a single estimate of enterprise value. In estimating the enterprise value of a portfolio company, the Company analyzes various factors consistent with industry practice, including but not limited to original transaction multiples, the portfolio company’s historical and projected financial results, applicable market trading and transaction comparables, applicable market yields and leverage levels, the nature and realizable value of any collateral, the markets in which the portfolio company does business, and comparisons of financial ratios of peer companies that are public. Typically, the enterprise values of private companies are based on multiples of earnings before interest, income taxes, depreciation and amortization (“EBITDA”), cash flows, net income, revenues, or in limited cases, book value. In addition, for certain debt investments, the Company may base its valuation on indicative bid and ask prices provided by an independent third-party pricing service. Bid prices reflect the highest price that the Company and others may be willing to pay. Ask prices represent the lowest price that the Company and others may be willing to accept. The Company generally uses the midpoint of the bid/ask range as its best estimate of fair value of such investment. As of September 30, 2023, the Valuation Designee determined, in good faith, the fair value of the Company’s portfolio investments in accordance with GAAP and the Company’s valuation procedures based on the facts and circumstances known by the Company at that time, or reasonably expected to be known at that time. Foreign Currency Forward Contracts The valuation for the Company’s foreign currency forward contracts is based on the difference between the exchange rate associated with the forward contract and the exchange rate at the current period end. Foreign currency forward contracts are categorized as Level 2 in the fair value hierarchy. Fair Value Disclosures The following tables present fair value measurements of investments and foreign currency forward contracts, by major class according to the fair value hierarchy: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements September 30, 2023 ​ Level 1 ​ Level 2 ​ Level 3 ​ Total Investments: ​ ​ ​ ​ Senior secured loans ​ $ — ​ $ — ​ $ 416,316 ​ $ 416,316 Unitranche secured loans ​ — ​ — ​ 13,548 ​ 13,548 Junior secured loans ​ — ​ — ​ 27,425 ​ 27,425 Equity securities ​ 229 ​ — ​ 27,497 ​ 27,726 Investments measured at NAV (1) (2) ​ — ​ — ​ — ​ 33,269 Total investments ​ $ 229 ​ $ — ​ $ 484,786 ​ $ 518,284 Foreign currency forward contracts asset (liability) ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements December 31, 2022 ​ Level 1 ​ Level 2 ​ Level 3 ​ Total Investments: ​ ​ ​ ​ Senior secured loans ​ $ — ​ $ — ​ $ 434,023 ​ $ 434,023 Unitranche secured loans ​ — ​ — ​ 20,633 ​ 20,633 Junior secured loans ​ — ​ — ​ 22,193 ​ 22,193 Equity securities ​ 294 ​ — ​ 28,388 ​ 28,682 Investments measured at NAV (1) (2) ​ — ​ — ​ — ​ 35,509 Total investments ​ $ 294 ​ $ — ​ $ 505,237 ​ $ 541,040 Foreign currency forward contracts asset (liability) ​ $ — ​ $ 1,507 ​ $ — ​ $ 1,507 (1) Certain investments that are measured at fair value using the NAV have not been categorized in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the consolidated statements of assets and liabilities. (2) Represents the Company’s investment in LLC equity interests in SLF. The fair value of this investment has been determined using the NAV of the Company’s ownership interest in SLF’s members’ capital. Senior secured loans, unitranche secured loans and junior secured loans are collateralized by tangible and intangible assets of the borrowers. These investments include loans to entities that have some level of challenge in obtaining financing from other, more conventional institutions, such as a bank. Interest rates on these loans are either fixed or floating, and are based on current market conditions and credit ratings of the borrower. Excluding loans on non-accrual, the contractual interest rates on the loans ranged from 8.00% to 20.53% at September 30, 2023 and 8.00% to 19.50% at December 31, 2022. The maturity dates on the loans outstanding at September 30, 2023 range between October 2023 and July 2029. The following tables provide a reconciliation of the beginning and ending balances for investments at fair value that use Level 3 inputs for the three and nine months ended September 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of June 30, 2023 $ 415,873 $ 13,400 $ 25,307 $ 26,034 $ 480,614 Net realized gain (loss) on investments ​ — ​ — ​ — ​ 6 ​ 6 Net change in unrealized gain (loss) on investments ​ (3,554) ​ (43) ​ (690) ​ (100) ​ (4,387) Purchases of investments and other adjustments to cost (1) ​ 13,259 ​ 210 ​ 1,746 ​ 83 ​ 15,298 Proceeds from principal payments and sales of investments (2) ​ (5,971) ​ (19) ​ (749) ​ (6) ​ (6,745) Reclassifications (3) ​ ​ (3,291) ​ ​ — ​ ​ 1,811 ​ ​ 1,480 ​ ​ — Balance as of September 30, 2023 ​ $ 416,316 ​ $ 13,548 ​ $ 27,425 ​ $ 27,497 ​ $ 484,786 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of December 31, 2022 $ 434,023 $ 20,633 $ 22,193 $ 28,388 $ 505,237 Net realized gain (loss) on investments ​ (9,787) ​ (24,768) ​ — ​ (4,465) ​ (39,020) Net change in unrealized gain (loss) on investments ​ (2,734) ​ 24,746 ​ (1,743) ​ 1,793 ​ 22,062 Purchases of investments and other adjustments to cost (1) ​ 54,107 ​ 295 ​ 4,564 ​ 1,304 ​ 60,270 Proceeds from principal payments and sales of investments (2) ​ (53,234) ​ (7,358) ​ (2,168) ​ (1,003) ​ (63,763) Reclassifications (3) ​ ​ (6,059) ​ ​ — ​ ​ 4,579 ​ ​ 1,480 ​ ​ — Balance as of September 30, 2023 ​ $ 416,316 ​ $ 13,548 ​ $ 27,425 ​ $ 27,497 ​ $ 484,786 (1) Includes purchases of new investments, effects of refinancing and restructurings, premium and discount accretion and amortization and PIK interest. (2) Represents net proceeds from investments sold and principal paydowns received. (3) Represents non-cash reclassification of investment type due to a restructuring. The following tables provide a reconciliation of the beginning and ending balances for investments at fair value that use Level 3 inputs for the three and nine months ended September 30, 2022. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of June 30, 2022 $ 415,244 $ 34,114 $ 19,745 $ 28,837 $ 497,940 Net realized gain (loss) on investments ​ (1,672) ​ — ​ (1) ​ 6 ​ (1,667) Net change in unrealized gain (loss) on investments ​ (3,788) ​ 10 ​ 1,314 ​ (2,604) ​ (5,068) Purchases of investments and other adjustments to cost (1) ​ 52,370 ​ 15 ​ 368 ​ 162 ​ 52,915 Proceeds from principal payments and sales of investments (2) ​ (59,925) ​ (13,096) ​ — ​ (6) ​ (73,027) Balance as of September 30, 2022 ​ $ 402,229 ​ $ 21,043 ​ $ 21,426 ​ $ 26,395 ​ $ 471,093 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of December 31, 2021 $ 423,700 $ 51,494 $ 14,364 $ 29,969 $ 519,527 Net realized gain (loss) on investments ​ (1,693) ​ (94) ​ (1) ​ 38 ​ (1,750) Net change in unrealized gain (loss) on investments ​ (8,838) ​ (5,146) ​ 992 ​ (4,114) ​ (17,106) Purchases of investments and other adjustments to cost (1) ​ 88,950 ​ 3,253 ​ 6,071 ​ 831 ​ 99,105 Proceeds from principal payments and sales of investments (2) ​ (99,890) ​ (28,464) ​ — ​ (329) ​ (128,683) Balance as of September 30, 2022 ​ $ 402,229 ​ $ 21,043 ​ $ 21,426 ​ $ 26,395 ​ $ 471,093 (1) Includes purchases of new investments, effects of refinancing and restructurings, premium and discount accretion and amortization and PIK interest. (2) Represents net proceeds from investments sold and principal paydowns received. The total net change in unrealized gain (loss) on investments included on the consolidated statements of operations for the three and nine months ended September 30, 2023, attributable to Level 3 investments still held at September 30, 2023, was ($5,664) and ($9,596), respectively. The total net change in unrealized gain (loss) on investments included on the consolidated statements of operations for the three and nine months ended September 30, 2022, attributable to Level 3 investments still held at September 30, 2022, was ($6,132) and ($16,041), respectively. Reclassifications impacting Level 3 of the fair value hierarchy are reported as transfers in or out of Level 3 as of the beginning of the period in which the reclassifications occur. There were no transfers among Levels 1, 2 and 3 during the three and nine months ended September 30, 2023 and 2022. Significant Unobservable Inputs ASC Topic 820 requires disclosure of quantitative information about the significant unobservable inputs used in the valuation of assets and liabilities classified as Level 3 within the fair value hierarchy. Disclosure of this information is not required in circumstances where a valuation (unadjusted) is obtained from a third-party pricing service and the information regarding the unobservable inputs is not reasonably available to the Company and as such, the disclosures provided below exclude those investments valued in that manner. The tables below are not intended to be all-inclusive, but rather to provide information on significant unobservable inputs and valuation techniques used by the Company. The valuation techniques and significant unobservable inputs used in recurring Level 3 fair value measurements of assets as of September 30, 2023 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unobservable ​ Average ​ Range ​ Fair Value Valuation Technique Input Mean Minimum Maximum Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior secured loans ​ $ 270,084 Discounted cash flow EBITDA multiples 10.5 x 5.8 x 22.0 x ​ ​ ​ ​ ​ Market yields ​ 13.7 % 9.5 % 29.3 % Senior secured loans ​ 108,565 Discounted cash flow Revenue multiples 5.5 x 0.8 x 11.5 x ​ ​ ​ ​ ​ Market yields ​ 12.6 % 11.0 % 17.5 % Senior secured loans ​ 18,020 Enterprise value Book value multiples 1.3 x 1.3 x 1.3 x Senior secured loans ​ 9,191 Liquidation Probability weighting of alternative outcomes 95.8 % 32.4 % 100.0 % Senior secured loans ​ ​ 6,752 ​ Enterprise value ​ Revenue multiples ​ 2.0 x 2.0 x 2.0 x Senior secured loans ​ 3,104 Enterprise value EBITDA multiples 8.2 x 5.5 x 8.3 x Unitranche secured loans ​ 9,828 Discounted cash flow EBITDA multiples 9.0 x 9.0 x 9.0 x ​ ​ ​ ​ Market yields 13.1 % 11.8 % 13.5 % Unitranche secured loans ​ 3,720 Discounted cash flow ​ Revenue multiples ​ 9.0 x 6.0 x 12.8 x ​ ​ ​ ​ Market yields 13.0 % 12.6 % 13.4 % Junior secured loans ​ 21,338 Discounted cash flow Market yields 13.7 % 12.9 % 15.6 % Junior secured loans ​ 2,574 Enterprise value Revenue multiples 2.0 x 2.0 x 2.0 x Junior secured loans ​ ​ 2,085 ​ Liquidation ​ Probability weighting of alternative outcomes ​ 250.3 % 0.0 % 250.3 % Junior secured loans ​ ​ 1,428 ​ Discounted cash flow ​ Revenue multiples ​ 0.4 x 0.1 x 0.8 x ​ ​ ​ ​ ​ ​ ​ Market yields ​ 13.3 % 12.0 % 16.1 % Equity securities ​ 18,542 Enterprise value EBITDA multiples 9.2 x 5.5 x 19.3 x Equity securities ​ 5,736 Enterprise value Revenue multiples 2.1 x 0.7 x 11.5 x Equity securities ​ 2,442 Option pricing model Volatility 63.0 % 32.0 % 72.5 % Equity securities ​ 357 Discounted cash flow EBITDA multiples 6.0 x 6.0 x 6.0 x ​ ​ ​ ​ ​ ​ ​ Market yields ​ 27.5 % 27.5 % 27.5 % Total Level 3 Assets ​ $ 483,766 (1) ​ ​ ​ ​ ​ ​ (1) Excludes investments of $ 1,020 at fair value where valuation (unadjusted) is obtained from a third-party pricing service or broker quote for which such disclosure is not required. The valuation techniques and significant unobservable inputs used in recurring Level 3 fair value measurements of assets as of December 31, 2022 were as follows : ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Fair ​ ​ ​ Unobservable ​ Average ​ Range ​ ​ Value ​ Valuation Technique ​ Input ​ Mean ​ Minimum ​ Maximum Assets: ​ ​ Senior secured loans ​ $ 276,433 Discounted cash flow EBITDA multiples 9.3 x 3.8 x 18.6 x ​ ​ Market yields 12.4 % 8.7 % 22.3 % Senior secured loans ​ 130,199 Discounted cash flow Revenue multiples 4.4 x 0.2 x 12.3 x ​ ​ ​ ​ ​ Market yields ​ 13.4 % 10.0 % 22.0 % Senior secured loans ​ 19,546 Enterprise value Book value multiples 1.2 x 1.2 x 1.2 x Senior secured loans ​ 5,706 Enterprise value Revenue multiples 2.5 x 2.5 x 2.5 x Senior secured loans ​ 1,488 Liquidation Probability weighting of alternative outcomes 71.3 % 29.1 % 100.0 % Senior secured loans ​ 80 Enterprise value EBITDA multiples 8.0 x 8.0 x 8.0 x Unitranche secured loans ​ 17,019 Discounted cash flow EBITDA multiples 8.8 x 8.8 x 8.8 x ​ ​ ​ ​ ​ ​ Market yields 11.2 % 9.1 % 13.0 % Unitranche secured loans ​ 3,614 Discounted cash flow Revenue multiples 8.9 x 5.8 x 12.5 x ​ ​ ​ ​ ​ ​ ​ Market yields ​ 11.9 % 11.6 % 12.1 % Junior secured loans ​ 20,311 Discounted cash flow Market yields 13.6 % 12.3 % 20.4 % Junior secured loans ​ 1,882 Liquidation Probability weighting of alternative outcomes 225.8 % 225.8 % 225.8 % Equity securities ​ 16,630 Enterprise value EBITDA multiples 9.0 x 3.8 x 16.0 x Equity securities ​ 7,502 Enterprise value Revenue multiples 2.3 x 0.2 x 12.3 x Equity securities ​ 2,173 Option pricing model Volatility 66.6 % 49.4 % 70.0 % Equity securities ​ 397 Discounted cash flow EBITDA multiples 7.0 x 7.0 x 7.0 x Total Level 3 Assets ​ $ 502,980 (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) Excludes investments of $2,257 at fair value where valuation (unadjusted) is obtained from a third-party pricing service or broker quote for which such disclosure is not required. The significant unobservable input used in the income approach of fair value measurement of the Company’s investments is the discount rate used to discount the estimated future cash flows expected to be received from the underlying investment, which include both future principal and interest payments. Increases (decreases) in the discount rate would result in a decrease (increase) in the fair value estimate of the investment. Included in the consideration and selection of discount rates are the following factors: risk of default, rating of the investment and comparable investments, and call provisions. The significant unobservable inputs used in the market approach of fair value measurement of the Company’s investments are the market multiples of EBITDA or revenue of the comparable guideline public companies. The Company selects a population of public companies for each investment with similar operations and attributes of the portfolio company. Using these guideline public companies’ data, a range of multiples of enterprise value to EBITDA or revenue is calculated. The Company selects percentages from the range of multiples for purposes of determining the portfolio company’s estimated enterprise value based on said multiple and generally the latest twelve months EBITDA or revenue of the portfolio company (or other meaningful measure). Increases (decreases) in the multiple will result in an increase (decrease) in enterprise value, resulting in an increase (decrease) in the fair value estimate of the investment. Other Financial Assets and Liabilities ASC Topic 820 requires disclosure of the fair value of financial instruments for which it is practical to estimate such value. The Company believes that the carrying amounts of its other financial instruments such as cash, receivables and payables approximate the fair value of such items due to the short maturity of such instruments. Fair value of the Company’s revolving credit facility is estimated by discounting remaining payments using applicable market rates or market quotes for similar instruments at the measurement date, if applicable. As of both September 30, 2023 and December 31, 2022, the Company believes that the carrying value of its revolving credit facility approximates fair value. The senior unsecured notes (“2026 Notes”) are carried at cost and with their longer maturity dates, fair value is estimated by discounting remaining payments using current market rates for similar instruments and considering such factors as the legal maturity date and the ability of market participants to prepay the notes. As of September 30, 2023 and December 31, 2022, the estimated fair value of the Company’s 2026 Notes was $116,903 and $116,995, respectively.

Transactions with Affiliated Co

Transactions with Affiliated Companies	9 Months Ended
	Sep. 30, 2023
Transactions with Affiliated Companies
Transactions with Affiliated Companies	Note 5. Transactions with Affiliated Companies An affiliated company is a company in which the Company has an ownership interest of 5% or more of its voting securities. A controlled affiliate company is a company in which the Company has an ownership interest of more than 25% of its voting securities. Please see the Company’s consolidated schedule of investments for the type of investment, principal amount, interest rate including the spread, and the maturity date. Transactions related to the Company’s investments with affiliates for the nine months ended September 30, 2023 and 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Sales and ​ PIK ​ ​ ​ ​ ​ ​ ​ Net ​ ​ ​ ​ ​ Fair value at ​ Transfers ​ Purchases ​ paydowns ​ interest ​ Discount ​ Net realized ​ unrealized ​ Fair value at Portfolio Company December 31, 2022 in (out) (cost) (cost) (cost) accretion gain (loss) gain (loss) September 30, 2023 Non-Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ American Community Homes, Inc. ​ $ 8,953 ​ $ — ​ $ — ​ $ — ​ $ 1,165 ​ $ — ​ $ — ​ $ (1,925) ​ $ 8,193 American Community Homes, Inc. ​ ​ 4,258 ​ ​ — ​ ​ — ​ ​ — ​ ​ 757 ​ ​ — ​ ​ — ​ ​ (985) ​ ​ 4,030 American Community Homes, Inc. ​ ​ 543 ​ ​ — ​ ​ — ​ ​ — ​ ​ 70 ​ ​ — ​ ​ — ​ ​ (116) ​ ​ 497 American Community Homes, Inc. ​ ​ 1,996 ​ ​ — ​ ​ — ​ ​ — ​ ​ 259 ​ ​ — ​ ​ — ​ ​ (429) ​ ​ 1,826 American Community Homes, Inc. ​ ​ 3,694 ​ ​ — ​ ​ — ​ ​ — ​ ​ 481 ​ ​ — ​ ​ — ​ ​ (794) ​ ​ 3,381 American Community Homes, Inc. ​ ​ 17 ​ ​ — ​ ​ — ​ ​ — ​ ​ 2 ​ ​ — ​ ​ — ​ ​ (3) ​ ​ 16 American Community Homes, Inc. ​ ​ 85 ​ ​ — ​ ​ — ​ ​ — ​ ​ 11 ​ ​ — ​ ​ — ​ ​ (19) ​ ​ 77 American Community Homes, Inc. (Revolver) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — American Community Homes, Inc. (4,940 shares of common stock) (1) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 19,546 ​ ​ — ​ ​ — ​ ​ — ​ ​ 2,745 ​ ​ — ​ ​ — ​ ​ (4,271) ​ ​ 18,020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ascent Midco, LLC ​ ​ 6,217 ​ — ​ ​ — ​ ​ (6,175) ​ ​ — ​ ​ 16 ​ ​ — ​ ​ (58) ​ ​ — Ascent Midco, LLC (Revolver) ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Ascent Midco, LLC (2,032,258 Class A units) ​ ​ 1,969 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (55) ​ ​ 1,914 ​ ​ ​ 8,186 ​ — ​ ​ — ​ ​ (6,175) ​ ​ — ​ ​ 16 ​ ​ — ​ ​ (113) ​ ​ 1,914 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C Parent Holdings, LLC. ​ 146 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (146) ​ ​ — C Parent Holdings, LLC. (58,779 shares of common stock) (2) ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 146 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (146) ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Familia Dental Group Holdings, LLC (1,212 Class A units) ​ ​ 2,625 ​ — ​ ​ 122 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (396) ​ ​ 2,351 ​ ​ ​ 2,625 ​ — ​ ​ 122 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (396) ​ ​ 2,351 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HFZ Capital Group, LLC ​ ​ 16,159 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 803 ​ ​ 16,962 HFZ Capital Group, LLC ​ ​ 5,805 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 289 ​ ​ 6,094 MC Asset Management (Corporate), LLC ​ ​ 8,421 ​ — ​ ​ — ​ ​ — ​ ​ 1,311 ​ ​ — ​ ​ — ​ ​ — ​ ​ 9,732 MC Asset Management (Corporate), LLC ​ ​ 1,000 ​ — ​ ​ 1,586 ​ ​ — ​ ​ 317 ​ ​ — ​ ​ — ​ ​ — ​ ​ 2,903 MC Asset Management (Corporate), LLC (15.9% of interests) ​ ​ 1,291 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (59) ​ ​ 1,232 ​ ​ ​ 32,676 ​ — ​ ​ 1,586 ​ ​ — ​ ​ 1,628 ​ ​ — ​ ​ — ​ ​ 1,033 ​ ​ 36,923 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mnine Holdings, Inc. ​ ​ — ​ ​ — ​ ​ 105 ​ ​ (52) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 53 Mnine Holdings, Inc. ​ ​ 5,492 ​ — ​ ​ — ​ ​ — ​ ​ 569 ​ ​ 12 ​ ​ — ​ ​ (14) ​ ​ 6,059 Mnine Holdings, Inc. ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Mnine Holdings, Inc. (Revolver) ​ ​ 214 ​ ​ — ​ ​ 308 ​ ​ — ​ ​ 11 ​ ​ — ​ ​ — ​ ​ — ​ ​ 533 Mnine Holdings, Inc. (6,400 Class B units) ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 5,706 ​ — ​ ​ 413 ​ ​ (52) ​ ​ 580 ​ ​ 12 ​ ​ — ​ ​ (14) ​ ​ 6,645 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NECB Collections, LLC (Revolver) ​ ​ 382 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 42 ​ ​ 424 NECB Collections, LLC, LLC (20.8% of LLC units) ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 382 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 42 ​ ​ 424 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Second Avenue SFR Holdings II LLC (Revolver) (3) ​ ​ 4,755 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 4,761 ​ ​ ​ 4,755 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 4,761 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SFR Holdco, LLC (Junior secured loan) ​ ​ 5,850 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 508 ​ ​ 6,358 SFR Holdco, LLC (24.4% of interests) ​ ​ 3,900 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 339 ​ ​ 4,239 ​ ​ ​ 9,750 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 847 ​ ​ 10,597 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TJ Management HoldCo, LLC (Revolver) ​ ​ 80 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 80 TJ Management HoldCo, LLC (16 shares of common stock) ​ ​ 2,766 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 417 ​ ​ 3,183 ​ ​ ​ 2,846 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 417 ​ ​ 3,263 Total non-controlled affiliate company investments ​ $ 86,618 ​ $ — ​ $ 2,121 ​ $ (6,227) ​ $ 4,953 ​ $ 28 ​ $ — ​ $ (2,595) ​ $ 84,898 Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MRCC Senior Loan Fund I, LLC ​ $ 35,509 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (2,240) ​ $ 33,269 ​ ​ ​ 35,509 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (2,240) ​ ​ 33,269 Total controlled affiliate company investments ​ $ 35,509 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (2,240) ​ $ 33,269 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value at ​ ​ ​ ​ Sales and PIK ​ ​ Net Net Fair value at ​ ​ December 31, ​ Transfers ​ Purchases ​ paydowns ​ interest ​ Discount ​ realized ​ unrealized ​ September Portfolio Company ​ 2021 ​ in (out) ​ (cost) ​ (cost) ​ (cost) ​ accretion ​ gain (loss) ​ gain (loss) ​ 30, 2022 Non-controlled affiliate company investment: ​ ​ ​ ​ ​ ​ ​ ​ ​ American Community Homes, Inc. ​ $ 10,457 ​ $ — ​ $ — ​ $ — ​ $ 466 ​ $ — ​ $ — ​ $ (1,889) ​ $ 9,034 American Community Homes, Inc. ​ 4,753 ​ — ​ — ​ — ​ 384 ​ — ​ — ​ (888) ​ 4,249 American Community Homes, Inc. ​ 634 ​ — ​ — ​ — ​ 28 ​ — ​ — ​ (114) ​ 548 American Community Homes, Inc. ​ 3,164 ​ — ​ — ​ — ​ 104 ​ — ​ — ​ (1,254) ​ 2,014 American Community Homes, Inc. ​ 4,357 ​ — ​ — ​ — ​ 192 ​ — ​ — ​ (821) ​ 3,728 American Community Homes, Inc. ​ 20 ​ — ​ — ​ — ​ 1 ​ — ​ — ​ (3) ​ 18 American Community Homes, Inc. ​ ​ 99 ​ ​ — ​ ​ — ​ ​ — ​ ​ 4 ​ ​ — ​ ​ — ​ ​ (18) ​ ​ 85 American Community Homes, Inc. (Revolver) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — American Community Homes, Inc. (warrant to purchase up to 22.3% of the equity) (1) ​ 264 ​ — ​ — ​ — ​ — ​ — ​ — ​ (264) ​ — ​ ​ 23,748 ​ — ​ — ​ — ​ 1,179 ​ — ​ — ​ (5,251) ​ 19,676 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ascent Midco, LLC ​ 6,392 ​ — ​ — ​ (130) ​ — ​ 19 ​ — ​ (121) ​ 6,160 Ascent Midco, LLC (Revolver) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — Ascent Midco, LLC ( 2,032,258 Class A units) ​ 2,554 ​ — ​ — ​ — ​ — ​ — ​ — ​ (1,136) ​ 1,418 ​ ​ 8,946 ​ — ​ — ​ (130) ​ — ​ 19 ​ — ​ (1,257) ​ 7,578 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Curion Holdings, LLC (2) ​ 4,561 ​ — ​ — ​ (4,497) ​ — ​ — ​ — ​ 82 ​ 146 Curion Holdings, LLC (Revolver) (2) ​ 550 ​ — ​ 92 ​ (620) ​ — ​ — ​ — ​ (22) ​ — Curion Holdings, LLC (Junior secured loan) (2) ​ — ​ — ​ — ​ — ​ — ​ — ​ (1) ​ 1 ​ — Curion Holdings, LLC (Junior secured loan) (2) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — Curion Holdings, LLC ( 58,779 shares of common stock) (2) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 5,111 ​ — ​ 92 ​ (5,117) ​ — ​ — ​ (1) ​ 61 ​ 146 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Familia Dental Group Holdings, LLC ( 1,158 Class A units) ​ 1,919 ​ — ​ 183 ​ — ​ — ​ — ​ — ​ 406 ​ 2,508 ​ ​ 1,919 ​ — ​ 183 ​ — ​ — ​ — ​ — ​ 406 ​ 2,508 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HFZ Capital Group, LLC ​ 15,084 ​ — ​ — ​ — ​ — ​ — ​ — ​ 804 ​ 15,888 HFZ Capital Group, LLC ​ 5,420 ​ — ​ — ​ — ​ — ​ — ​ — ​ 288 ​ 5,708 MC Asset Management (Corporate), LLC ​ 7,154 ​ — ​ — ​ — ​ 903 ​ — ​ — ​ — ​ 8,057 MC Asset Management (Corporate), LLC (Delayed Draw) ​ 850 ​ — ​ — ​ — ​ 107 ​ — ​ — ​ — ​ 957 MC Asset Management (Corporate), LLC ( 15.9% of interests) ​ 644 ​ — ​ — ​ — ​ — ​ — ​ — ​ 107 ​ 751 ​ ​ 29,152 ​ — ​ — ​ — ​ 1,010 ​ — ​ — ​ 1,199 ​ 31,361 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mnine Holdings, Inc. ​ 5,771 ​ — ​ — ​ — ​ 230 ​ 12 ​ — ​ (12) ​ 6,001 Mnine Holdings, Inc. (Revolver) ​ ​ — ​ ​ — ​ ​ 240 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 240 Mnine Holdings, Inc. ( 6,400 Class B units) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 5,771 ​ — ​ 240 ​ — ​ 230 ​ 12 ​ — ​ (12) ​ 6,241 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NECB Collections, LLC (Revolver) ​ 632 ​ — ​ — ​ — ​ — ​ — ​ — ​ (206) ​ 426 NECB Collections, LLC ( 20.8% of LLC units) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 632 ​ — ​ — ​ — ​ — ​ — ​ — ​ (206) ​ 426 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Second Avenue SFR Holdings II LLC (Revolver) (3) ​ ​ 2,104 ​ ​ — ​ ​ 2,681 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (18) ​ ​ 4,767 ​ ​ ​ 2,104 ​ ​ — ​ ​ 2,681 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (18) ​ ​ 4,767 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SFR Holdco, LLC (Junior secured loan) ​ ​ 5,850 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 5,850 SFR Holdco, LLC ( 24.4% of interests) ​ ​ 3,900 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 3,900 ​ ​ 9,750 ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ 9,750 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TJ Management HoldCo, LLC (Revolver) ​ — ​ — ​ 80 ​ — ​ — ​ — ​ — ​ — ​ 80 TJ Management HoldCo, LLC ( 16 shares of common stock) ​ 3,148 ​ — ​ — ​ — ​ — ​ — ​ — ​ (407) ​ 2,741 ​ ​ 3,148 ​ — ​ 80 ​ — ​ — ​ — ​ — ​ (407) ​ 2,821 Total non-controlled affiliate company investments ​ $ 90,281 ​ $ — ​ $ 3,276 ​ $ (5,247) ​ $ 2,419 ​ $ 31 ​ $ (1) ​ $ (5,485) ​ $ 85,274 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MRCC Senior Loan Fund I, LLC ​ $ 41,125 ​ $ — ​ $ 500 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (5,081) ​ $ 36,544 ​ ​ 41,125 ​ — ​ 500 ​ — ​ — ​ — ​ — ​ (5,081) ​ 36,544 Total controlled affiliate company investments ​ $ 41,125 ​ $ — ​ $ 500 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (5,081) ​ $ 36,544 (1) On December 29, 2022, the Company exercised the American Community Homes, Inc. (“ACH”) warrants held by the Company. The Company acquired 4,940 shares of ACH’s common stock, or 22.3% of the equity, in exchange for a nominal exercise price in accordance with the terms of the warrant. (2) During the year ended December 31, 2022, C Parent Holdings, LLC (fka Curion Holdings, LLC) (“Curion”) sold the underlying operating company and repaid the Company’s debt investment. The remaining fair value at December 31, 2022, represented the remaining expected escrow proceeds associated with the sale. During 2023, all expected proceeds associated with the sale were received. The Company no longer holds an equity investment in Curion as of September 30, 2023. (3) Second Avenue SFR Holdings II LLC is a related entity to SFR Holdco, LLC and is being presented as a non-controlled affiliate for that reason. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ 2023 ​ 2022 ​ ​ Interest ​ Dividend ​ ​ ​ ​ Interest ​ Dividend ​ ​ ​ Portfolio Company ​ Income Income Fee Income Income Income Fee Income Non-controlled affiliate company investments: ​ ​ ​ ​ ​ ​ American Community Homes, Inc. ​ $ 1,163 ​ $ — ​ $ — ​ $ 878 ​ $ — ​ $ — American Community Homes, Inc. ​ 755 ​ — ​ — ​ 575 ​ — ​ — American Community Homes, Inc. ​ 71 ​ — ​ — ​ 53 ​ — ​ — American Community Homes, Inc. ​ 259 ​ — ​ — ​ 196 ​ — ​ — American Community Homes, Inc. ​ 480 ​ — ​ — ​ 362 ​ — ​ — American Community Homes, Inc. ​ 3 ​ — ​ — ​ 2 ​ — ​ — American Community Homes, Inc. ​ 11 ​ — ​ — ​ 8 ​ — ​ — American Community Homes, Inc. (Revolver) ​ 2 ​ — ​ — ​ 19 ​ — ​ — American Community Homes, Inc. (Common stock) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 2,744 ​ — ​ — ​ 2,093 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ascent Midco, LLC ​ 384 ​ — ​ — ​ 359 ​ — ​ — Ascent Midco, LLC (Revolver) ​ 2 ​ — ​ — ​ 3 ​ — ​ — Ascent Midco, LLC (Class A units) ​ — ​ 152 ​ — ​ — ​ 141 ​ — ​ ​ 386 ​ 152 ​ — ​ 362 ​ 141 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C Parent Holdings, LLC. ​ 172 ​ — ​ — ​ 1,766 ​ — ​ — C Parent Holdings, LLC. (Revolver) ​ ​ — ​ ​ — ​ ​ — ​ ​ 294 ​ ​ — ​ ​ — C Parent Holdings, LLC. (Common stock) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 172 ​ — ​ — ​ 2,060 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Familia Dental Group Holdings, LLC (Class A units) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HFZ Capital Group, LLC ​ 1,749 ​ — ​ — ​ 1,430 ​ — ​ — HFZ Capital Group, LLC ​ 629 ​ — ​ — ​ 514 ​ — ​ — MC Asset Management (Corporate), LLC ​ 1,417 ​ — ​ — ​ 940 ​ — ​ — MC Asset Management (Corporate), LLC (Delayed Draw) ​ 417 ​ — ​ — ​ 111 ​ — ​ — MC Asset Management (Corporate), LLC (LLC interest) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 4,212 ​ — ​ — ​ 2,995 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mnine Holdings, Inc. ​ 600 ​ — ​ — ​ 567 ​ — ​ — Mnine Holdings, Inc. ​ ​ — ​ ​ — ​ ​ — ​ ​ 2 ​ ​ — ​ ​ — Mnine Holdings, Inc. (Revolver) ​ ​ 47 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Mnine Holdings, Inc. (Class B units) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 647 ​ — ​ — ​ 569 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NECB Collections, LLC (Revolver) ​ — ​ — ​ — ​ — ​ — ​ — NECB Collections, LLC (LLC units) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Second Avenue SFR Holdings II LLC (Revolver) ​ 434 ​ — ​ — ​ 182 ​ — ​ — ​ ​ ​ 434 ​ ​ — ​ ​ — ​ ​ 182 ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SFR Holdco, LLC (Junior secured loan) ​ 351 ​ — ​ — ​ 351 ​ — ​ — SFR Holdco, LLC (LLC interest) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 351 ​ — ​ — ​ 351 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TJ Management HoldCo, LLC (Revolver) ​ 13 ​ — ​ — ​ 9 ​ — ​ — TJ Management HoldCo, LLC (Common stock) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 13 ​ — ​ — ​ 9 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total non-controlled affiliate company investments ​ $ 8,959 ​ $ 152 ​ $ — ​ $ 8,621 ​ $ 141 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ MRCC Senior Loan Fund I, LLC ​ $ — ​ $ 2,700 ​ $ — ​ $ — ​ $ 2,700 ​ $ — ​ ​ — ​ 2,700 ​ — ​ — ​ 2,700 ​ — Total controlled affiliate company investments ​ $ — ​ $ 2,700 ​ $ — ​ $ — ​ $ 2,700 ​ $ — ​

Transactions with Related Parti

Transactions with Related Parties	9 Months Ended
	Sep. 30, 2023
Transactions with Related Parties
Transactions with Related Parties	Note 6. Transactions with Related Parties The Company has entered into an investment advisory agreement with MC Advisors (the “Investment Advisory Agreement”), under which MC Advisors, subject to the overall supervision of the Board, provides investment advisory services to the Company. The Company pays MC Advisors a fee for its services under the Investment Advisory Agreement consisting of two components — a base management fee and an incentive fee. The cost of both the base management fee and the incentive fee are borne by the Company’s stockholders, unless such fees are waived by MC Advisors. The base management fee is calculated initially at an annual rate equal to 1.75% of average invested assets (calculated as total assets excluding cash, which includes assets financed using leverage); provided, however, the base management fee is calculated at an annual rate equal to 1.00% of the Company’s average invested assets (calculated as total assets excluding cash, which includes assets financed using leverage) that exceeds the product of (i) 200% and (ii) the Company’s average net assets. For the avoidance of doubt, the 200% is calculated in accordance with the asset coverage limitation as defined in the 1940 Act to give effect to the Company’s exemptive relief with respect to MRCC SBIC’s SBA debentures during the period they were outstanding. This has the effect of reducing the Company’s base management fee rate on assets in excess of regulatory leverage of 1:1 debt to equity to 1.00% per annum. The base management fee is payable quarterly in arrears. Base management fees for the three and nine months ended September 30, 2023 were $2,140 and $6,503, respectively. Base management fees for the three and nine months ended September 30, 2022 were $2,222 and $6,834, respectively. MC Advisors elected to voluntarily waive zero and $55 of such base management fees for the three and nine months ended September 30, 2022, respectively. MC Advisors did not waive any base management fees during the three and nine months ended September 30, 2023. The incentive fee consists of two parts. The first part is calculated and payable quarterly in arrears and equals 20% of “pre-incentive fee net investment income” for the immediately preceding quarter, subject to a 2% (8% annualized) preferred return, or “hurdle,” and a “catch up” feature. The foregoing incentive fee is subject to a total return requirement, which provides that no incentive fee in respect of pre-incentive fee net investment income will be payable except to the extent that 20% of the cumulative net increase in net assets resulting from operations over the then current and 11 preceding calendar quarters exceeds the cumulative incentive fees accrued and/or paid for the 11 preceding calendar quarters (the “Incentive Fee Limitation”). Therefore, any ordinary income incentive fee that is payable in a calendar quarter will be limited to the lesser of (1) 20% of the amount by which pre-incentive fee net investment income for such calendar quarter exceeds the 2% hurdle, subject to the “catch-up” provision, and (2) (x) 20% of the cumulative net increase in net assets resulting from operations for the then current and 11 preceding calendar quarters minus (y) the cumulative incentive fees accrued and/or paid for the 11 preceding calendar quarters. For the foregoing purpose, the “cumulative net increase in net assets resulting from operations” is the sum of pre-incentive fee net investment income, realized gains and losses and unrealized gains and losses for the then current and 11 preceding calendar quarters. The second part of the incentive fee is determined and payable in arrears as of the end of each fiscal year in an amount equal to 20% of realized capital gains, if any, on a cumulative basis from inception through the end of the year, computed net of all realized capital losses on a cumulative basis and unrealized depreciation, less the aggregate amount of any previously paid capital gain incentive fees. The composition of the Company’s incentive fees was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, Nine months ended September 30, ​ ​ 2023 2022 ​ 2023 2022 Part one incentive fees (1) ​ $ 1,355 ​ $ 1,565 ​ $ 4,493 ​ $ 2,747 Part two incentive fees (2) ​ — ​ — ​ — ​ — Incentive fees, excluding the impact of the incentive fee waiver ​ 1,355 ​ 1,565 ​ 4,493 ​ 2,747 Incentive fee waiver (3) ​ — ​ — ​ — ​ (525) Total incentive fees, net of incentive fee waiver ​ $ 1,355 ​ $ 1,565 ​ $ 4,493 ​ $ 2,222 (1) Based on pre-incentive fee net investment income. (2) Based upon net realized and unrealized gains and losses, or capital gains. The Company accrues, but does not pay, a capital gains incentive fee in connection with any unrealized capital appreciation, as appropriate. If, on a cumulative basis, the sum of net realized gain (loss) plus net unrealized gain (loss) decreases during a period, the Company will reverse any excess capital gains incentive fee previously accrued such that the amount of capital gains incentive fee accrued is no more than 20% of the sum of net realized gain (loss) plus net unrealized gain (loss). (3) Represents part one incentive fees waived by MC Advisors. The Company has entered into an administration agreement with MC Management (the “Administration Agreement”), under which the Company reimburses MC Management, subject to the review and approval of the Board, for its allocable portion of overhead and other expenses, including the costs of furnishing the Company with office facilities and equipment and providing clerical, bookkeeping, record-keeping and other administrative services at such facilities, and the Company’s allocable portion of the cost of the chief financial officer and chief compliance officer and their respective staffs. To the extent that MC Management outsources any of its functions, the Company will pay the fees associated with such functions on a direct basis, without incremental profit to MC Management. For the three and nine months ended September 30, 2023, the Company incurred $721 and $2,041, respectively, in administrative expenses (included within Professional fees, Administrative service fees and General and administrative expenses on the consolidated statements of operations) under the Administration Agreement, of which $228 and $707, respectively, was related to MC Management overhead and salary allocation and paid directly to MC Management. For the three and nine months ended September 30, 2022, the Company incurred $703 and $2,370, respectively, in administrative expenses (included within Professional fees, Administrative service fees and General and administrative expenses on the consolidated statements of operations) under the Administration Agreement, of which $275 and $908, respectively, was related to MC Management overhead and salary allocation and paid directly to MC Management. As of September 30, 2023 and December 31, 2022, $245 and $255, respectively, of expenses were due to MC Management under this agreement and are included in accounts payable and accrued expenses on the consolidated statements of assets and liabilities. The Company has entered into a license agreement with Monroe Capital LLC under which Monroe Capital LLC has agreed to grant the Company a non-exclusive, royalty-free license to use the name “Monroe Capital” for specified purposes in its business. Under this agreement, the Company has the right to use the “Monroe Capital” name at no cost, subject to certain conditions, for so long as MC Advisors or one of its affiliates remains its investment adviser. Other than with respect to this limited license, the Company has no legal right to the “Monroe Capital” name or logo. As of September 30, 2023 and December 31, 2022, the Company had accounts payable to members of the Board of $38 and zero, respectively, representing accrued and unpaid fees for their services.

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2023
Borrowings
Borrowings	Note 7. Borrowings In accordance with the 1940 Act, the Company is permitted to borrow amounts such that its asset coverage ratio, as defined in the 1940 Act, is at least 150% after such borrowing. As of September 30, 2023 and December 31, 2022, the Company’s asset coverage ratio based on aggregate borrowings outstanding was 163% and 167%, respectively. Revolving Credit Facility The Company’s ability to borrow under the revolving credit facility is subject to availability under the borrowing base, which permits the Company to borrow up to 72.5% of the fair market value of its portfolio company investments depending on the type of investment the Company holds and whether the investment is quoted. The Company’s ability to borrow is also subject to certain concentration limits, and continued compliance with the representations, warranties and covenants given by the Company under the facility. The revolving credit facility contains certain financial covenants, including, but not limited to, the Company’s maintenance of: (1) minimum consolidated total net assets at least equal to $150,000 plus 65% of the net proceeds to the Company from sales of its equity securities after March 1, 2019; (2) a ratio of total assets (less total liabilities other than indebtedness) to total indebtedness of not less than 1.5 to 1; and (3) a senior debt coverage ratio of at least 2 to 1. The revolving credit facility also requires the Company to undertake customary indemnification obligations with respect to ING Capital LLC and other members of the lending group and to reimburse the lenders for expenses associated with entering into the credit facility. The revolving credit facility also has customary provisions regarding events of default, including events of default for nonpayment, change in control transactions at both Monroe Capital Corporation and MC Advisors, failure to comply with financial and negative covenants, and failure to maintain the Company’s relationship with MC Advisors. If the Company incurs an event of default under the revolving credit facility and fails to remedy such default under any applicable grace period, if any, then the entire revolving credit facility could become immediately due and payable, which would materially and adversely affect the Company’s liquidity, financial condition, results of operations and cash flows. The Company’s revolving credit facility also imposes certain conditions that may limit the amount of the Company’s distributions to stockholders. Distributions payable in the Company’s common stock under the DRIP are not limited by the revolving credit facility. Distributions in cash or property other than common stock are generally limited to 115% of the amount of distributions required to maintain the Company’s status as a RIC. As of September 30, 2023 and December 31, 2022, the Company had U.S. dollar borrowings of $201,100 and $204,600, respectively, and no borrowings denominated in a foreign currency as of either date. Any borrowings denominated in a foreign currency may be positively or negatively affected by movements in the rate of exchange between the U.S. dollar and the respective foreign currency. These movements are beyond the control of the Company and cannot be predicted. Borrowings denominated in a foreign currency are translated into U.S. dollars based on the spot rate at each balance sheet date. The impact resulting from changes in foreign currency borrowings is included in net change in unrealized gain (loss) on foreign currency and other transactions on the Company’s consolidated statements of operations and totaled zero for both the three and nine months ended September 30, 2023, and zero and $157 for the three and nine months ended September 30, 2022, respectively. During the nine months ended September 30, 2022, the Company repaid borrowings denominated in Great Britain pounds of £3,433. As a result of this repayment, the Company recognized a realized gain (loss) on foreign currency and other transactions on the Company’s consolidated statements of operations of ($11) for the nine months ended September 30, 2022. Borrowings under the revolving credit facility bear interest, at the Company’s election, at an annual rate of SOFR (one-month, or three-month at the Company’s discretion based on the term of the borrowing) plus 2.625% or at a daily rate equal to 1.625% per annum plus the greater of 1.5%, the prime interest rate, the federal funds rate plus 0.5% or SOFR plus 1.0%, with a SOFR floor of 0.5%. In addition to the stated interest rate on borrowings under the revolving credit facility, the Company is required to pay a commitment fee and certain conditional fees based on usage of the expanded borrowing base and usage of the asset coverage ratio flexibility. A commitment fee of 0.5% per annum on any unused portion of the revolving credit facility if the utilized portion of the facility is greater than 35% of the then available maximum borrowing or a commitment fee of 1.0% per annum on any unused portion of the revolving credit facility if the utilized portion of the facility is less than or equal to 35% of the then available maximum borrowing. As of September 30, 2023 and December 31, 2022, the outstanding borrowings were accruing at a weighted average interest rate of 8.1% and 7.0%, respectively. 2026 Notes: SBA Debentures: Debt – Modifications and Extinguishments ​ Components of interest expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, ​ ​ ​ 2023 ​ 2022 Interest expense - revolving credit facility ​ $ 3,989 ​ $ 2,186 ​ Interest expense - 2026 Notes ​ 1,555 ​ 1,555 ​ Amortization of deferred financing costs ​ 330 ​ 522 ​ Total interest and other debt financing expenses ​ $ 5,874 ​ $ 4,263 ​ Average debt outstanding ​ $ 319,759 ​ $ 292,879 ​ Average stated interest rate ​ 6.8 % 5.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, ​ 2023 2022 Interest expense - revolving credit facility ​ $ 11,536 ​ $ 5,391 ​ Interest expense - 2026 Notes ​ 4,665 ​ 4,665 ​ Interest expense - SBA debentures ​ — ​ 292 ​ Amortization of deferred financing costs ​ 977 ​ 1,613 ​ Total interest and other debt financing expenses ​ $ 17,178 ​ $ 11,961 ​ Average debt outstanding ​ $ 322,918 ​ $ 315,166 ​ Average stated interest rate ​ 6.7 % 4.3 % ​

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2023
Derivative Instruments
Derivative Instruments	Note 8. Derivative Instruments The Company enters into foreign currency forward contracts from time to time to help mitigate the impact that an adverse change in foreign exchange rates would have on future interest cash flows from the Company’s investments denominated in foreign currencies. As of September 30, 2023, the Company held no foreign currency forward contracts. As of December 31, 2022, the counterparty to these foreign currency forward contracts was Bannockburn Global Forex, LLC. Net unrealized gain or loss on foreign currency forward contracts are included in net change in unrealized gain (loss) on foreign currency forward contracts and net realized gain or loss on forward currency forward contracts are included in net realized gain (loss) on foreign currency forward contracts on the accompanying consolidated statements of operations. Certain information related to the Company’s foreign currency forward contracts is presented below as of December 31, 2022. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Notional ​ ​ ​ Amount of ​ Amount of ​ ​ ​ ​ Amount to be ​ Settlement ​ Unrealized ​ Unrealized ​ ​ Description ​ Sold Date Gain Loss Balance Sheet location of Net Amounts Foreign currency forward contract AUD 153 1/18/2023 $ 14 $ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 140 2/16/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 132 3/16/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 160 4/20/2023 ​ 14 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 121 5/16/2023 ​ 11 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 156 6/19/2023 ​ 14 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 138 7/18/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 146 8/16/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 146 9/18/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 148 10/18/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 140 11/16/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 142 12/18/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 150 1/17/2024 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 143 2/16/2024 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 15,410 3/18/2024 ​ 1,329 ​ — Unrealized gain on foreign currency forward contracts ​ ​ ​ ​ ​ ​ ​ $ 1,507 ​ $ — ​ ​ ​ For the three and nine months ended September 30, 2023, the Company recognized net change in unrealized gain (loss) on foreign currency forward contracts of zero and ($1,507), respectively. For the three and nine months ended September 30, 2023, the Company recognized net realized gain (loss) on foreign currency forward contracts of zero and $1,756, respectively. For the three and nine months ended September 30, 2022, the Company recognized net change in unrealized gain (loss) on foreign currency forward contracts of $863 and $1,503, respectively. For the three and nine months ended September 30, 2022, the Company recognized net realized gain (loss) on foreign currency forward contracts of $38 and $69, respectively.

Distributions

Distributions	9 Months Ended
	Sep. 30, 2023
Distributions
Distributions	Note 9. Distributions The Company’s distributions are recorded on the record date. The following table summarizes distributions declared during the nine months ended September 30, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DRIP Shares ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount ​ ​ ​ ​ DRIP ​ DRIP ​ Repurchased ​ Cost of Date ​ Record ​ Payment ​ Per ​ Cash ​ Shares ​ Shares ​ in the Open ​ DRIP Shares Declared Date Date Share Distribution Issued Value Market Repurchased Nine months ended September 30, 2023: March 1, 2023 ​ March 15, 2023 ​ March 31, 2023 ​ $ 0.25 ​ $ 5,417 ​ — ​ $ — ​ 10,380 ​ $ 81 June 2, 2023 ​ June 15, 2023 ​ June 30, 2023 ​ ​ 0.25 ​ ​ 5,417 ​ — ​ ​ — ​ 9,045 ​ ​ 73 September 1, 2023 ​ September 15, 2023 ​ September 29, 2023 ​ ​ 0.25 ​ ​ 5,417 ​ — ​ ​ — ​ 16,514 ​ ​ 123 Total distributions declared ​ ​ ​ ​ $ 0.75 ​ $ 16,251 — ​ $ — 35,939 $ 277 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2022: March 2, 2022 ​ March 16, 2022 ​ March 31, 2022 ​ $ 0.25 ​ $ 5,417 — ​ $ — 25,229 ​ $ 276 June 1, 2022 ​ June 15, 2022 ​ June 30, 2022 ​ ​ 0.25 ​ ​ 5,416 ​ — ​ ​ — ​ 29,655 ​ ​ 280 September 1, 2022 ​ September 15, 2022 ​ September 30, 2022 ​ 0.25 ​ 5,416 — ​ — 20,789 ​ 164 Total distributions declared ​ ​ ​ ​ ​ $ 0.75 ​ $ 16,249 — ​ $ — 75,673 ​ $ 720 ​

Stock Issuances and Repurchases

Stock Issuances and Repurchases	9 Months Ended
	Sep. 30, 2023
Stock Issuances and Repurchases
Stock Issuances and Repurchases	Note 10. Stock Issuances and Repurchases Stock Issuances:

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies.
Commitments and Contingencies	Note 11. Commitments and Contingencies Commitments Indemnifications: Concentration of credit and counterparty risk: Market risk: Legal proceedings:

Financial Highlights

Financial Highlights	9 Months Ended
	Sep. 30, 2023
Financial Highlights
Financial Highlights	Note 12. Financial Highlights The following is a schedule of financial highlights for the nine months ended September 30, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 September 30, 2022 Per share data: ​ ​ ​ Net asset value at beginning of period ​ $ 10.39 ​ $ 11.51 ​ Net investment income (1) ​ 0.83 ​ 0.77 ​ Net gain (loss) (1) ​ (0.89) ​ (1.10) ​ Net increase (decrease) in net assets resulting from operations (1) ​ (0.06) ​ (0.33) ​ Stockholder distributions - income (2) ​ (0.75) ​ (0.75) ​ Net asset value at end of period ​ $ 9.58 ​ $ 10.43 ​ Net assets at end of period ​ $ 207,555 ​ $ 225,956 ​ Shares outstanding at end of period ​ 21,666,340 ​ 21,666,340 ​ Per share market value at end of period ​ $ 7.45 ​ $ 7.24 ​ Total return based on market value (3) ​ (4.08) % (30.10) % Total return based on average net asset value (4) ​ (0.56) % (3.05) % Ratio/Supplemental data: ​ ​ ​ ​ ​ Ratio of net investment income to average net assets (5) ​ 11.76 % 9.67 % Ratio of total expenses, net of base management fee and incentive fee waivers, to average net assets (5) (6) ​ 18.28 % 13.58 % Portfolio turnover (7) ​ 9.91 % 17.53 % (1) Calculated using the weighted average shares outstanding during the periods presented. (2) Management monitors available taxable earnings, including net investment income and realized capital gains, to determine if a tax return of capital may occur for the year. To the extent the Company’s taxable earnings fall below the total amount of the Company’s distributions for that fiscal year, a portion of those distributions may be deemed a tax return of capital to the Company’s stockholders. The tax character of distributions will be determined at the end of the fiscal year. However, if the character of such distributions were determined as of September 30, 2023 and 2022, none of the distributions would have been characterized as a tax return of capital to the Company’s stockholders; this tax return of capital may differ from the return of capital calculated with reference to net investment income for financial reporting purposes. (3) Total return based on market value is calculated assuming a purchase of common shares at the market value on the first day and a sale at the market value on the last day of the periods reported. Distributions, if any, are assumed for purposes of this calculation to be reinvested at prices obtained under the Company’s DRIP. Total return based on market value does not reflect brokerage commissions. Return calculations are not annualized. (4) Total return based on average net asset value is calculated by dividing the net increase (decrease) in net assets resulting from operations by the average net asset value. Return calculations are not annualized. (5) Ratios are annualized. Incentive fees included within the ratio are not annualized. (6) The following is a schedule of supplemental ratios for the three and nine months ended September 30, 2023 and 2022. These ratios have been annualized unless otherwise noted. ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 September 30, 2022 Ratio of total investment income to average net assets 30.04 % 23.25 % Ratio of interest and other debt financing expenses to average net assets 10.57 % 6.72 % Ratio of total expenses (without base management fee waivers and incentive fees) to average net assets 16.21 % 12.67 % Ratio of incentive fees, net of incentive fee waivers, to average net assets (7) (8) 2.07 % 0.93 % (7) Ratios are not annualized. (8) The ratio of waived incentive fees to average net assets was zero and 0.22% for the nine months ended September 30, 2023 and 2022, respectively.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The accompanying consolidated financial statements of the Company and related financial information have been prepared pursuant to the requirements for reporting on Form 10-Q and Articles 6 and 10 of Regulation S-X. The Company has determined it meets the definition of an investment company and follows the accounting and reporting guidance in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 946 – Financial Services – Investment Companies
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Consolidation	Consolidation As permitted under ASC Topic 946, the Company will generally not consolidate its investment in a portfolio company other than an investment company subsidiary or a controlled operating company whose business consists of providing services to the Company. Accordingly, the Company consolidated the results of the Company’s wholly-owned subsidiaries, including Monroe Capital Corporation SBIC, LP (“MRCC SBIC”) (through its dissolution date on March 31, 2022) and its wholly-owned general partner MCC SBIC GP, LLC, and the Company’s wholly-owned taxable subsidiaries (the “Taxable Subsidiaries”) in its consolidated financial statements. The purpose of the Taxable Subsidiaries is to permit the Company to hold equity investments in portfolio companies that are taxed as partnerships for U.S. federal income tax purposes while complying with the “source of income” requirements contained in the RIC tax provisions. The Taxable Subsidiaries are not consolidated with the Company for U.S. federal corporate income tax purposes, and each Taxable Subsidiary is subject to U.S. federal corporate income tax on its taxable income. All intercompany balances and transactions have been eliminated. The Company does not consolidate its non-controlling interest in MRCC Senior Loan Fund I, LLC (“SLF”). See further description of the Company’s investment in SLF in Note 3.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company applies fair value to substantially all of its financial instruments in accordance with ASC Topic 820 — Fair Value Measurements and Disclosures ASC Topic 820 requires disclosure of the fair value of financial instruments for which it is practical to estimate such value. The Company believes that the carrying amounts of its other financial instruments such as cash, receivables and payables approximate the fair value of such items due to the short maturity of such instruments.
Revenue Recognition	Revenue Recognition The Company’s revenue recognition policies are as follows: Investments and related investment income: Dividend income on preferred equity securities is recorded as dividend income on an accrual basis to the extent that such amounts are payable by the portfolio company and are expected to be collected. Dividend income on common equity securities is recorded on the record date for private portfolio companies. Each distribution received from limited liability company (“LLC”) and limited partnership (“LP”) investments is evaluated to determine if the distribution should be recorded as dividend income or a return of capital. Generally, the Company will not record distributions from equity investments in LLCs and LPs as dividend income unless there are sufficient accumulated tax-basis earnings and profits in the LLC or LP prior to the applicable distribution. Distributions that are classified as a return of capital are recorded as a reduction in the cost basis of the investment. For both the three and nine months ended September 30, 2023, the Company received return of capital distributions from its equity investments of zero. For the three and nine months ended September 30, 2022, the Company received return of capital distributions from its equity investments and its investment in LLC equity in SLF of zero and $290, respectively. The Company has certain investments in its portfolio that contain a payment-in-kind (“PIK”) provision, which represents contractual interest or dividends that are added to the principal balance and recorded as income. The Company stops accruing PIK interest or PIK dividends when it is determined that PIK interest or PIK dividends are no longer collectible. To maintain RIC tax treatment, and to avoid incurring corporate U.S. federal income tax, substantially all of this income must be paid out to stockholders in the form of distributions, even though the Company has not yet collected the cash. Loan origination fees, original issue discount and market discount or premiums are capitalized, and the Company then amortizes such amounts using the effective interest method as interest income over the life of the investment. Unamortized discounts and loan origination fees totaled $4,149 and $4,701 as of September 30, 2023 and December 31, 2022, respectively. Upfront loan origination and closing fees received for the three and nine months ended September 30, 2023 totaled $202 and $1,003, respectively. Upfront loan origination and closing fees received for the three and nine months ended September 30, 2022 totaled $1,126 and $1,871, respectively. Upon prepayment of a loan or debt security, any unamortized premium or discount or loan origination fees are recorded as interest income. The components of the Company’s investment income were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ September 30, ​ 2023 2022 Interest income ​ $ 12,804 ​ $ 12,491 PIK interest income ​ 2,430 ​ 1,240 Dividend income (1) ​ 1,017 ​ 1,051 Fee income (3) ​ (836) ​ 412 Prepayment gain (loss) ​ 29 ​ 495 Accretion of discounts and amortization of premiums ​ 199 ​ 227 Total investment income ​ $ 15,643 ​ $ 15,916 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended ​ ​ September 30, ​ ​ 2023 ​ 2022 Interest income ​ $ 37,553 ​ $ 30,602 PIK interest income 7,193 4,458 Dividend income (2) ​ 3,169 ​ 3,108 Fee income (3) ​ (356) ​ 1,604 Prepayment gain (loss) ​ 378 ​ 758 Accretion of discounts and amortization of premiums ​ 857 ​ 872 Total investment income ​ $ 48,794 ​ $ 41,402 (1) Includes PIK dividends of $117 and $124 , respectively. (2) Includes PIK dividends of $359 and $350 , respectively. (3) Includes the reversal of $1,046 of previously accrued fee income associated with the Company’s former loan investment in IT Global Holding, LLC. Investment transactions are recorded on a trade-date basis. Realized gains or losses on portfolio investments are calculated based upon the difference between the net proceeds from the disposition and the amortized cost basis of the investment, without regard to unrealized gains or losses previously recognized. Realized gains and losses are recorded within net realized gain (loss) on investments on the consolidated statements of operations. Changes in the fair value of investments from the prior period, as determined through the application of the Company’s valuation policy, are included within net change in unrealized gain (loss) on investments on the consolidated statements of operations. Non-accrual:
Distributions	Distributions Distributions to common stockholders are recorded on the applicable record date. The amount, if any, to be distributed to common stockholders is determined by the Board each quarter and is generally based upon the Company’s earnings estimated by management. Net realized capital gains, if any, are generally distributed at least annually. The determination of the tax attributes for the Company’s distributions is made annually, based upon its taxable income for the full year and distributions paid for the full year. Ordinary dividend distributions from a RIC do not qualify for the preferential tax rate on qualified dividend income from domestic corporations and qualified foreign corporations, except to the extent that the RIC received the income in the form of qualifying dividends from domestic corporations and qualified foreign corporations. The tax attributes for distributions will generally include both ordinary income and capital gains, but may also include qualified dividends or return of capital. In October 2012, the Company adopted a dividend reinvestment plan (“DRIP”) that provides for the reinvestment of dividends on behalf of its stockholders, unless a stockholder has elected to receive dividends in cash. When the Company declares a cash dividend, the Company’s stockholders who have not “opted out” of the DRIP at least three days prior to the dividend payment date will have their cash dividend automatically reinvested into additional shares of the Company’s common stock. The Company has the option to satisfy the share requirements of the DRIP through the issuance of new shares of common stock or through open market purchases of common stock by the DRIP plan administrator. Newly issued shares are valued based upon the final closing price of the Company’s common stock on a date determined by the Board. Shares purchased in the open market to satisfy the DRIP requirements will be valued based upon the average price of the applicable shares purchased by the DRIP plan administrator, before any associated brokerage or other costs. See Note 9 for additional information on the Company’s distributions.
Segments	Segments In accordance with ASC Topic 280 — Segment Reporting
Cash	Cash The Company deposits its cash in a financial institution and, at times, such balances may be in excess of the Federal Deposit Insurance Corporation insurance limits.
Unamortized Deferred Financing Costs	Unamortized Deferred Financing Costs Deferred financing costs represent fees and other direct incremental costs incurred in connection with the Company’s borrowings. As of September 30, 2023 and December 31, 2022, the Company had unamortized deferred financing costs of $3,566 and $4,486 respectively, presented as a direct reduction of the carrying amount of debt on the consolidated statements of assets and liabilities. These amounts are amortized and included in interest and other debt financing expenses on the consolidated statements of operations over the estimated average life of the borrowings. Amortization of deferred financing costs for the three and nine months ended September 30, 2023 was $330 and $977, respectively. Amortization of deferred financing costs for the three and nine months ended September 30, 2022 was $522 and $1,613, respectively.
Offering Costs	Offering Costs Offering costs include, among other things, fees paid in relation to legal, accounting, regulatory and printing work completed in preparation of debt and equity offerings. Offering costs from equity offerings are charged against the proceeds from the offering within the consolidated statements of changes in net assets. Offering costs from debt offerings are reclassified to unamortized deferred financing costs on the consolidated statements of assets and liabilities as noted above. As of September 30, 2023 and December 31, 2022, other assets on the consolidated statements of assets and liabilities included $262 and $184, respectively, of deferred offering costs, which will be charged against the proceeds from future debt or equity offerings when completed.
Investments Denominated in Foreign Currency	Investments Denominated in Foreign Currency As of September 30, 2023, the Company held no investments denominated in a foreign currency. As of December 31, 2022, the Company held investments in one portfolio company that was denominated in Australian dollars. At each balance sheet date, portfolio company investments denominated in foreign currencies are translated into U.S. dollars using the spot exchange rate on the last business day of the period. Purchases and sales of foreign portfolio company investments, and any income from such investments, are translated into U.S. dollars using the rates of exchange prevailing on the respective dates of such transactions. Although the fair values of foreign portfolio company investments and the fluctuation in such fair values are translated into U.S. dollars using the applicable foreign exchange rates described above, the Company does not isolate the portion of the change in fair value resulting from foreign currency exchange rates fluctuations from the change in fair value of the underlying investment. All fluctuations in fair value are included in net change in unrealized gain (loss) on investments on the Company’s consolidated statements of operations. Investments denominated in foreign currencies and foreign currency transactions may involve certain consideration and risks not typically associated with those of domestic origin, including unanticipated movements in the value of the foreign currency relative to the U.S. dollar.
Derivative Instruments	Derivative Instruments The Company may enter into foreign currency forward contracts to reduce the Company’s exposure to foreign currency exchange rate fluctuations. In a foreign currency forward contract, the Company agrees to receive or deliver a fixed quantity of one currency for another, at a pre-determined price at a future date. Foreign currency forward contracts are marked-to-market based on the difference between the forward rate and the exchange rate at the current period end. Unrealized gain (loss) on foreign currency forward contracts is recorded on the Company’s consolidated statements of assets and liabilities by counterparty on a net basis. The Company does not utilize hedge accounting and as such values its foreign currency forward contracts at fair value with the change in unrealized gain or loss recorded in net change in unrealized gain (loss) on foreign currency forward contracts and the realized gain or loss recorded in net realized gain (loss) on foreign currency forward contracts on the Company’s consolidated statements of operations.
Income Taxes	Income Taxes The Company has elected to be treated as a RIC under Subchapter M of the Code and operates in a manner so as to qualify for the tax treatment available to RICs. To maintain qualification as a RIC, the Company must, among other things, meet certain source-of-income and asset diversification requirements and distribute to stockholders, for each taxable year, at least 90% of the Company’s “investment company taxable income,” which is generally the Company’s net ordinary income plus the excess, if any, of realized net short-term capital gains over realized net long-term capital losses. If the Company qualifies as a RIC and satisfies the annual distribution requirement, the Company will not have to pay corporate-level federal income taxes on any income that the Company distributes to its stockholders. The Company intends to make distributions in an amount sufficient to maintain RIC status each year and to avoid any federal income taxes on income. The Company is also subject to nondeductible federal excise taxes if the Company does not distribute at least 98% of net ordinary income, 98.2% of any capital gain net income, if any, and any recognized and undistributed income from prior years for which it paid no federal income taxes. To the extent that the Company determines that its estimated current year annual taxable income may exceed estimated current year dividend distributions, the Company accrues excise tax, calculated as 4% of the estimated excess taxable income, if any, as taxable income is earned. For the three and nine months ended September 30, 2023, the Company recorded a net expense (benefit) on the consolidated statements of operations of $95 and $345, respectively, for U.S. federal excise tax. For the three and nine months ended September 30, 2022, the Company recorded a net expense (benefit) on the consolidated statements of operations of ($55) and $64, respectively, for U.S. federal excise tax. As of September 30, 2023 and December 31, 2022, the Company had payables for excise taxes of $106 and $1, respectively, which were included in other assets and accounts payable and accrued expenses, respectively, on the Company’s consolidated statements of assets and liabilities. The Company’s consolidated Taxable Subsidiaries may be subject to U.S. federal and state corporate-level income taxes. For the three and nine months ended September 30, 2023, the Company recorded a net tax expense of zero and $150 on the consolidated statements of operations for these subsidiaries. For the three and nine months ended September 30, 2022, the Company recorded a net tax expense of $923 and $1,225 on the consolidated statements of operations for these subsidiaries. As of both September 30, 2023 and December 31, 2022, the Company did not have any payables for corporate-level income taxes. The Company accounts for income taxes in conformity with ASC Topic 740 — Income Taxes
Subsequent Events	Subsequent Events The Company has evaluated the need for disclosures and/or adjustments resulting from subsequent events through the date the consolidated financial statements were issued. There have been no subsequent events that occurred during such period that would require disclosure in this Form 10-Q or would be required to be recognized in the consolidated financial statements as of and for the nine months ended September 30, 2023.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2023
Summary of Significant Accounting Policies
Schedule of components of the Company's investment income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ September 30, ​ 2023 2022 Interest income ​ $ 12,804 ​ $ 12,491 PIK interest income ​ 2,430 ​ 1,240 Dividend income (1) ​ 1,017 ​ 1,051 Fee income (3) ​ (836) ​ 412 Prepayment gain (loss) ​ 29 ​ 495 Accretion of discounts and amortization of premiums ​ 199 ​ 227 Total investment income ​ $ 15,643 ​ $ 15,916 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended ​ ​ September 30, ​ ​ 2023 ​ 2022 Interest income ​ $ 37,553 ​ $ 30,602 PIK interest income 7,193 4,458 Dividend income (2) ​ 3,169 ​ 3,108 Fee income (3) ​ (356) ​ 1,604 Prepayment gain (loss) ​ 378 ​ 758 Accretion of discounts and amortization of premiums ​ 857 ​ 872 Total investment income ​ $ 48,794 ​ $ 41,402 (1) Includes PIK dividends of $117 and $124 , respectively. (2) Includes PIK dividends of $359 and $350 , respectively. (3) Includes the reversal of $1,046 of previously accrued fee income associated with the Company’s former loan investment in IT Global Holding, LLC.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2023
Investments
Schedule of composition of the company's investment portfolio	The following tables show the composition of the Company’s investment portfolio, at amortized cost and fair value (with corresponding percentage of total portfolio investments): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 December 31, 2022 Amortized Cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior secured loans $ 419,994 78.2 % $ 436,066 75.3 % Unitranche secured loans ​ 13,522 2.5 ​ 45,352 7.8 ​ Junior secured loans ​ 29,215 5.4 ​ 21,141 3.6 ​ LLC equity interest in SLF ​ 42,650 8.0 ​ 42,650 7.4 ​ Equity securities ​ 31,414 5.9 ​ 34,098 5.9 ​ Total ​ $ 536,795 100.0 % $ 579,307 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Fair Value: ​ ​ ​ Senior secured loans ​ $ 416,316 80.3 % $ 434,023 80.2 % Unitranche secured loans ​ 13,548 2.6 ​ 20,633 3.8 ​ Junior secured loans ​ 27,425 5.3 ​ 22,193 4.1 ​ LLC equity interest in SLF ​ 33,269 6.4 ​ 35,509 6.6 ​ Equity securities ​ 27,726 5.4 ​ 28,682 5.3 ​ Total ​ $ 518,284 100.0 % $ 541,040 100.0 % ​ The following tables show the composition of the Company’s investment portfolio by geographic region, at amortized cost and fair value (with corresponding percentage of total portfolio investments). The geographic composition is determined by the location of the corporate headquarters of the portfolio company, which may not be indicative of the primary source of the portfolio company’s business: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Amortized Cost: ​ ​ ​ International ​ $ — 0.0 % $ 11,860 2.1 % Midwest ​ 163,145 30.4 ​ 157,558 27.2 ​ Northeast ​ 106,674 19.9 ​ 100,961 17.4 ​ Southeast ​ 158,568 29.5 ​ 158,548 27.4 ​ Southwest ​ 25,008 4.7 ​ 27,348 4.7 ​ West ​ 83,400 15.5 ​ 123,032 21.2 ​ Total ​ $ 536,795 100.0 % $ 579,307 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Fair Value: ​ ​ ​ International ​ $ — 0.0 % $ 10,405 1.9 % Midwest ​ 141,810 27.4 ​ 143,691 26.6 ​ Northeast ​ 109,509 21.1 ​ 104,157 19.2 ​ Southeast ​ 154,441 29.8 ​ 155,624 28.8 ​ Southwest ​ 25,931 5.0 ​ 28,287 5.2 ​ West ​ 86,593 16.7 ​ 98,876 18.3 ​ Total ​ $ 518,284 100.0 % $ 541,040 100.0 % ​ The following tables show the composition of the Company’s investment portfolio by industry, at amortized cost and fair value (with corresponding percentage of total portfolio investments): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 December 31, 2022 Amortized Cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense $ 7,601 1.4 % $ 7,461 1.3 % Automotive ​ 17,781 3.3 ​ 16,775 2.9 ​ Banking ​ 17,031 3.2 ​ 17,790 3.1 ​ Beverage, Food & Tobacco ​ 9,924 1.9 ​ 15,625 2.7 ​ Capital Equipment ​ 18,442 3.4 ​ 18,615 3.2 ​ Chemicals, Plastics & Rubber ​ 2,917 0.5 ​ 2,924 0.5 ​ Construction & Building ​ 8,698 1.6 ​ 6,642 1.1 ​ Consumer Goods: Durable ​ 8,792 1.6 ​ 9,333 1.6 ​ Consumer Goods: Non-Durable ​ 3,415 0.6 ​ 28,276 4.9 ​ Environmental Industries ​ 5,434 1.0 ​ 6,164 1.1 ​ FIRE: Finance ​ 14,585 2.7 ​ 25,021 4.3 ​ FIRE: Real Estate ​ 86,633 16.1 ​ 81,922 14.1 ​ Healthcare & Pharmaceuticals ​ 67,025 12.5 ​ 59,659 10.3 ​ High Tech Industries ​ 41,358 7.7 ​ 52,385 9.0 ​ Hotels, Gaming & Leisure ​ 111 0.0 ​ 2,702 0.5 ​ Investment Funds & Vehicles ​ 42,650 8.0 ​ 42,650 7.4 ​ Media: Advertising, Printing & Publishing ​ 18,241 3.4 ​ 17,470 3.0 ​ Media: Broadcasting & Subscription ​ 3,984 0.7 ​ 2,747 0.5 ​ Media: Diversified & Production ​ 41,260 7.7 ​ 36,018 6.2 ​ Retail ​ 2,422 0.5 ​ 9,247 1.6 ​ Services: Business ​ 56,224 10.5 ​ 56,249 9.7 ​ Services: Consumer ​ 39,028 7.3 ​ 40,086 6.9 ​ Telecommunications ​ 7,246 1.4 ​ 7,502 1.3 ​ Wholesale ​ 15,993 3.0 ​ 16,044 2.8 ​ Total ​ $ 536,795 100.0 % $ 579,307 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ December 31, 2022 Fair Value: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense $ 7,578 1.4 % $ 7,436 1.4 % Automotive ​ 16,626 3.2 ​ 16,637 3.1 ​ Banking ​ 16,436 3.2 ​ 19,817 3.7 ​ Beverage, Food & Tobacco ​ 11,434 2.2 ​ 12,470 2.3 ​ Capital Equipment ​ 18,936 3.6 ​ 19,012 3.5 ​ Chemicals, Plastics & Rubber ​ 3,996 0.8 ​ 4,445 0.8 ​ Construction & Building ​ 8,800 1.7 ​ 6,706 1.2 ​ Consumer Goods: Durable ​ 8,739 1.7 ​ 9,338 1.7 ​ Consumer Goods: Non-Durable ​ 3,023 0.6 ​ 3,508 0.6 ​ Environmental Industries ​ 5,895 1.1 ​ 6,558 1.2 ​ FIRE: Finance ​ 15,037 2.9 ​ 23,892 4.4 ​ FIRE: Real Estate ​ 85,387 16.5 ​ 82,498 15.2 ​ Healthcare & Pharmaceuticals ​ 66,309 12.8 ​ 59,273 11.0 ​ High Tech Industries ​ 40,164 7.7 ​ 52,891 9.8 ​ Hotels, Gaming & Leisure ​ 115 0.0 ​ 2,720 0.5 ​ Investment Funds & Vehicles ​ 33,269 6.4 ​ 35,509 6.6 ​ Media: Advertising, Printing & Publishing ​ 20,497 4.0 ​ 19,777 3.7 ​ Media: Broadcasting & Subscription ​ 2,763 0.5 ​ 2,691 0.5 ​ Media: Diversified & Production ​ 41,435 8.0 ​ 36,164 6.7 ​ Retail ​ 1,985 0.4 ​ 9,306 1.7 ​ Services: Business ​ 57,316 11.1 ​ 57,308 10.6 ​ Services: Consumer ​ 30,398 5.9 ​ 31,324 5.8 ​ Telecommunications ​ 7,356 1.4 ​ 7,595 1.4 ​ Wholesale ​ 14,790 2.9 ​ 14,165 2.6 ​ Total ​ $ 518,284 100.0 % $ 541,040 100.0 %
Summary of SLF's portfolio, followed by a listing of the individual investments in SLF's portfolio	Below is a summary of SLF’s portfolio, followed by a listing of the individual investments in SLF’s portfolio as of September 30, 2023 and December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ September 30, 2023 ​ December 31, 2022 Senior secured loans (1) 166,639 197,867 ​ Weighted average current interest rate on senior secured loans (2) 9.7 % 9.7 % Number of portfolio company investments in SLF 53 60 ​ Largest portfolio company investment (1) 6,597 6,650 ​ Total of five largest portfolio company investments (1) 26,900 27,026 ​ (1) Represents outstanding principal amount, excluding unfunded commitments. (2) Computed as the (a) annual stated interest rate on accruing senior secured loans divided by (b) total senior secured loans at outstanding principal amount. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest ​ ​ ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) Index (b) Spread (b) Rate (b) Maturity ​ Principal Fair Value Non-Controlled/Non-Affiliate Company Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Secured Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bromford Industries Limited (c) ​ P ​ 5.25 % 13.75 % (e) ​ 11/5/2025 ​ ​ ​ 2,744 ​ $ 971 Bromford Industries Limited (c) ​ P ​ 5.25 % 13.75 % (e) ​ 11/5/2025 ​ ​ ​ 1,829 ​ ​ 648 Trident Maritime Systems, Inc. ​ SF ​ 5.60 % 10.99 % ​ 2/26/2027 ​ ​ ​ 2,422 ​ ​ 2,399 Trident Maritime Systems, Inc. ​ SF ​ 5.60 % 10.99 % ​ 2/26/2027 ​ ​ ​ 746 ​ ​ 739 Trident Maritime Systems, Inc. (Revolver) ​ SF ​ 5.60 % 10.92 % ​ 2/26/2027 ​ ​ ​ 319 ​ ​ 316 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8,060 ​ ​ 5,073 Automotive ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accelerate Auto Works Intermediate, LLC ​ SF ​ 5.15 % 10.57 % ​ 12/1/2027 ​ ​ ​ 1,358 ​ ​ 1,344 Accelerate Auto Works Intermediate, LLC (Delayed Draw) (d) ​ SF ​ 5.15 % 10.57 % ​ 12/1/2027 ​ ​ ​ 388 ​ ​ — Accelerate Auto Works Intermediate, LLC (Revolver) (d) ​ SF ​ 5.15 % 10.57 % ​ 12/1/2027 ​ ​ ​ 132 ​ ​ — Truck-Lite Co., LLC ​ SF ​ 6.25 % 11.69 % ​ 12/14/2026 ​ ​ ​ 1,678 ​ ​ 1,678 Truck-Lite Co., LLC ​ SF ​ 6.25 % 11.69 % ​ 12/14/2026 ​ ​ ​ 249 ​ ​ 249 Truck-Lite Co., LLC ​ SF ​ 6.25 % 11.69 % ​ 12/14/2026 ​ ​ ​ 43 ​ ​ 43 Wheel Pros, Inc. (f) ​ SF ​ 4.61 % 9.94 % ​ 5/11/2028 ​ ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 3,848 ​ ​ 3,314 Beverage, Food & Tobacco ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SW Ingredients Holdings, LLC ​ SF ​ 4.75 % 10.17 % ​ 7/3/2025 ​ ​ ​ 3,553 ​ ​ 3,551 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 3,553 ​ ​ 3,551 Capital Equipment ​ ​ ​ ​ ​ ​ ​ DS Parent, Inc. ​ SF ​ 5.75 % 11.34 % ​ 12/8/2028 ​ ​ ​ 2,738 ​ ​ 2,714 MacQueen Equipment, LLC ​ SF ​ 5.51 % 10.90 % ​ 1/7/2028 ​ ​ ​ 2,080 ​ ​ 2,080 MacQueen Equipment, LLC (Delayed Draw) (d) ​ SF ​ 5.51 % 10.90 % ​ 1/7/2028 ​ ​ ​ 591 ​ ​ 78 MacQueen Equipment, LLC (Revolver) (d) SF 5.51 % 10.90 % ​ 1/7/2028 ​ ​ 296 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,705 ​ ​ 4,872 Chemicals, Plastics & Rubber ​ ​ ​ ​ ​ ​ Phoenix Chemical Holding Company LLC SF ​ 7.11 % 12.43 % ​ 8/2/2024 ​ ​ 1,131 ​ 1,030 TJC Spartech Acquisition Corp. ​ SF ​ 4.75 % 10.05 % ​ 5/5/2028 ​ ​ ​ 4,221 ​ ​ 3,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,352 ​ ​ 4,829 Construction & Building ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Cook & Boardman Group LLC SF ​ 5.85 % 11.18 % ​ 10/20/2025 ​ ​ 2,857 ​ 2,785 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,857 ​ ​ 2,785 Consumer Goods: Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Elevate Textiles, Inc. (fka International Textile Group, Inc.) SF ​ 6.65 % 11.89 % (e) ​ 9/30/2027 ​ ​ 800 ​ 800 Runner Buyer INC. SF ​ 5.61 % 11.04 % ​ 10/23/2028 ​ ​ 2,955 ​ 2,352 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 3,755 ​ ​ 3,152 Consumer Goods: Non-Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PH Beauty Holdings III, INC. SF ​ 5.00 % 10.68 % ​ 9/26/2025 ​ ​ 2,374 ​ 2,018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,374 ​ ​ 2,018 Containers, Packaging & Glass ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Polychem Acquisition, LLC SF ​ 5.11 % 10.43 % ​ 3/17/2025 ​ ​ 2,865 ​ 2,865 PVHC Holding Corp ​ SF ​ 5.65 % 11.04 % Cash/ % PIK ​ 2/17/2027 ​ ​ 1,897 ​ 1,830 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,762 ​ 4,695 Energy: Oil & Gas ​ ​ ​ ​ ​ Drilling Info Holdings, Inc. SF 4.35 % 9.67 % ​ 7/30/2025 ​ ​ 4,434 ​ 4,299 Offen, Inc. SF 5.43 % 10.46 % ​ 6/22/2026 ​ ​ 2,249 ​ 2,249 Offen, Inc. SF 5.43 % 10.46 % ​ 6/22/2026 ​ ​ 861 ​ 861 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,544 ​ ​ 7,409 FIRE: Finance ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Harbour Benefit Holdings, Inc. ​ SF ​ 5.15 % 10.54 % ​ 12/13/2024 ​ ​ ​ 2,865 ​ ​ 2,865 Harbour Benefit Holdings, Inc. ​ SF ​ 5.10 % 10.42 % ​ 12/13/2024 ​ ​ ​ 61 ​ ​ 61 Minotaur Acquisition, Inc. ​ SF ​ 4.85 % 10.17 % ​ 3/27/2026 ​ ​ ​ 4,819 ​ ​ 4,808 TEAM Public Choices, LLC ​ SF ​ 5.43 % 10.88 % ​ 12/17/2027 ​ ​ ​ 2,932 ​ ​ 2,890 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,677 ​ ​ 10,624 FIRE: Real Estate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Avison Young (USA) Inc. (c) ​ SF ​ 6.76 % 12.15 % (e) ​ 1/30/2026 ​ ​ ​ 4,775 ​ ​ 1,892 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,775 ​ ​ 1,892 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) Index (b) Spread (b) Rate (b) Maturity Principal Fair Value Healthcare & Pharmaceuticals ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cano Health, LLC ​ SF ​ 4.10 % 9.42 % ​ 11/23/2027 ​ 1,955 ​ $ 1,272 HAH Group Holding Company LLC ​ SF ​ 5.00 % 10.42 % ​ 10/29/2027 ​ 2,958 ​ ​ 2,928 LSCS Holdings, Inc. ​ SF ​ 4.61 % 9.93 % ​ 12/15/2028 ​ 1,814 ​ ​ 1,792 Natus Medical Incorporated ​ SF ​ 5.50 % 11.04 % ​ 7/20/2029 ​ 4,962 ​ ​ 4,665 Paragon Healthcare, Inc. ​ SF ​ 5.85 % 11.17 % ​ 1/19/2027 ​ 2,111 ​ ​ 2,081 Paragon Healthcare, Inc. ​ SF ​ 5.75 % 11.12 % ​ 1/19/2027 ​ 364 ​ ​ 359 Paragon Healthcare, Inc. (Revolver) (d) ​ SF ​ 5.75 % 11.12 % ​ 1/19/2027 ​ 490 ​ ​ — Radiology Partners, Inc. ​ SF ​ 4.68 % 10.18 % ​ 7/9/2025 ​ 4,750 ​ ​ 3,599 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 19,404 ​ ​ 16,696 High Tech Industries ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corel Inc. (c) ​ SF ​ 5.10 % 10.52 % ​ 7/2/2026 ​ 3,450 ​ ​ 3,324 Lightbox Intermediate, L.P. ​ SF ​ 5.26 % 10.65 % ​ 5/11/2026 ​ 4,788 ​ ​ 4,644 TGG TS Acquisition Company ​ SF ​ 6.61 % 11.93 % ​ 12/12/2025 ​ 2,946 ​ ​ 2,886 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 11,184 ​ 10,854 Hotels, Gaming & Leisure ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Excel Fitness Holdings, Inc. ​ SF ​ 5.40 % 10.79 % ​ 4/27/2029 ​ 4,331 ​ ​ 4,108 Excel Fitness Holdings, Inc. (Revolver) (d) ​ SF ​ 5.40 % 10.79 % ​ 4/28/2028 ​ 625 ​ ​ — North Haven Spartan US Holdco, LLC ​ SF ​ 6.25 % 11.65 % ​ 6/6/2025 ​ 2,256 ​ ​ 2,242 Tait LLC ​ SF ​ 5.00 % 10.25 % ​ 3/28/2025 ​ 4,051 ​ ​ 4,027 Tait LLC (Revolver) (d) ​ SF ​ 5.00 % 10.25 % ​ 3/28/2025 ​ 769 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 12,032 ​ ​ 10,377 Media: Diversified & Production ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Research Now Group, Inc. and Survey Sampling International, LLC ​ SF ​ 5.76 % 11.13 % ​ 12/20/2024 ​ 6,597 ​ ​ 4,823 STATS Intermediate Holdings, LLC ​ SF ​ 5.51 % 10.89 % ​ 7/10/2026 ​ 4,813 ​ ​ 4,548 TA TT Buyer, LLC ​ SF ​ 5.00 % 10.39 % ​ 3/30/2029 ​ 3,300 ​ ​ 3,297 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 14,710 ​ ​ 12,668 Services: Business ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CHA Holdings, Inc ​ SF ​ 4.76 % 10.15 % ​ 4/10/2025 ​ 1,944 ​ ​ 1,913 CHA Holdings, Inc ​ SF ​ 4.76 % 10.15 % ​ 4/10/2025 ​ 410 ​ ​ 403 Eliassen Group, LLC ​ SF ​ 5.50 % 10.84 % ​ 4/14/2028 ​ 3,227 ​ ​ 3,173 Eliassen Group, LLC (Delayed Draw) (d) ​ SF ​ 5.50 % 10.82 % ​ 4/14/2028 ​ 740 ​ ​ 228 Engage2Excel, Inc. ​ SF ​ 7.35 % 12.21 % ​ 12/31/2023 ​ 4,282 ​ ​ 4,270 Engage2Excel, Inc. ​ SF ​ 7.35 % 12.21 % ​ 12/31/2023 ​ 773 ​ ​ 771 Engage2Excel, Inc. (Revolver) ​ SF ​ 7.35 % 12.69 % ​ 12/31/2023 ​ 550 ​ ​ 550 ​ ​ ​ ​ ​ ​ 10.82 % Cash/ ​ ​ ​ ​ ​ ​ ​ Output Services Group, Inc. ​ SF ​ 5.25 % 1.50 % PIK (e) ​ 6/29/2026 ​ 4,812 ​ ​ 1,011 Secretariat Advisors LLC ​ SF ​ 5.01 % 10.40 % ​ 12/29/2028 ​ 1,680 ​ ​ 1,663 Secretariat Advisors LLC ​ SF ​ 5.01 % 10.40 % ​ 12/29/2028 ​ 268 ​ ​ 265 SIRVA Worldwide Inc. ​ SF ​ 5.61 % 10.93 % ​ 8/4/2025 ​ 1,763 ​ ​ 1,589 Teneo Holdings LLC ​ SF ​ 5.35 % 10.67 % ​ 7/11/2025 ​ 4,800 ​ ​ 4,809 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 25,249 ​ ​ 20,645 Services: Consumer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 360Holdco, Inc. ​ SF ​ 5.60 % 10.92 % ​ 8/1/2025 ​ 2,130 ​ ​ 2,130 360Holdco, Inc. ​ SF ​ 5.60 % 10.92 % ​ 8/1/2025 ​ 823 ​ ​ 823 Laseraway Intermediate Holdings II, LLC ​ SF ​ 5.75 % 11.32 % ​ 10/14/2027 ​ 2,183 ​ ​ 2,153 McKissock Investment Holdings, LLC ​ SF ​ 5.00 % 10.43 % ​ 3/9/2029 ​ 2,463 ​ ​ 2,435 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,599 ​ ​ 7,541 Telecommunications ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Intermedia Holdings, Inc. ​ SF ​ 6.11 % 11.43 % ​ 7/21/2025 ​ 1,746 ​ ​ 1,665 Mavenir Systems, Inc. ​ SF ​ 5.11 % 10.49 % ​ 8/18/2028 ​ 1,642 ​ ​ 1,310 Sandvine Corporation ​ SF ​ 4.50 % 9.82 % ​ 10/31/2025 ​ 1,973 ​ ​ 1,699 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,361 ​ ​ 4,674 Transportation: Cargo ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Keystone Purchaser, LLC ​ SF ​ 5.75 % 10.96 % ​ 5/7/2027 ​ 4,917 ​ ​ 4,880 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,917 ​ ​ 4,880 Utilities: Oil & Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Dresser Utility Solutions, LLC ​ SF ​ 4.10 % 9.42 % ​ 10/1/2025 ​ 1,664 ​ ​ 1,631 Dresser Utility Solutions, LLC ​ SF ​ 5.35 % 10.67 % ​ 10/1/2025 ​ 243 ​ ​ 239 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1,907 ​ ​ 1,870 Wholesale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HALO Buyer, Inc. ​ SF ​ 4.60 % 9.92 % ​ 6/30/2025 ​ 4,736 ​ ​ 3,658 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,736 ​ ​ 3,658 Total Non-Controlled/Non-Affiliate Senior Secured Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 170,361 ​ $ 148,077 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity Securities (g) (h) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Consumer Goods: Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Elevate Textiles, Inc. (fka International Textile Group, Inc.) (25,524 shares of common units) ​ — ​ — ​ — (i) ​ — ​ — ​ ​ 75 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 75 Chemicals, Plastics & Rubber ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Polyventive Lender Holding Company LLC (0.84% of the equity) ​ — ​ — ​ — (i) ​ — ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ — Total Non-Controlled/Non-Affiliate Equities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 75 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TOTAL INVESTMENTS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 148,152 (a) All investments are U.S. companies unless otherwise noted. (b) The majority of investments bear interest at a rate that may be determined by reference to the London Interbank Offered Rate (“LIBOR” or “L”), Secured Overnight Financing Rate (“SOFR” or “SF”) or Prime (“P”) which reset daily, monthly, quarterly or semiannually. The Company has provided the spread over LIBOR, SOFR or Prime and the current contractual rate of interest in effect at September 30, 2023. Certain investments may be subject to an interest rate floor or cap. Certain investments contain a PIK provision. (c) This is an international company. (d) All or a portion of this commitment was unfunded as of September 30, 2023. As such, interest is earned only on the funded portion of this commitment. Principal reflects the commitment outstanding. (e) This position was on non-accrual status as of September 30, 2023, meaning that we have ceased accruing interest income on the position. (f) Investment position or portion thereof unsettled at September 30, 2023. (g) Represents less than 5% ownership of the portfolio company’s voting securities. (h) Ownership of certain equity investments may occur through a holding company partnership. (i) Represents a non-income producing security. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) ​ Index (b) ​ Spread (b) ​ Interest Rate (b) ​ Maturity ​ Principal ​ Fair Value Non-Controlled/Non-Affiliate Company Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Secured Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aerospace & Defense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Bromford Industries Limited (c) ​ P ​ 5.25 % ​ 12.75 % ​ 11/5/2025 ​ 2,744 ​ $ 2,581 Bromford Industries Limited (c) ​ P ​ 5.25 % ​ 12.75 % ​ 11/5/2025 ​ 1,829 ​ ​ 1,720 Trident Maritime Systems, Inc. ​ L ​ 4.75 % ​ 9.48 % ​ 2/26/2027 ​ 2,445 ​ ​ 2,443 Trident Maritime Systems, Inc. ​ L ​ 4.75 % ​ 9.48 % ​ 2/26/2027 ​ 746 ​ ​ 746 Trident Maritime Systems, Inc. (Revolver) (d) ​ L ​ 4.75 % ​ 9.08 % ​ 2/26/2027 ​ 319 ​ ​ 122 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8,083 ​ ​ 7,612 Automotive ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accelerate Auto Works Intermediate, LLC ​ L ​ 4.50 % ​ 9.23 % ​ 12/1/2027 ​ 1,391 ​ ​ 1,386 Accelerate Auto Works Intermediate, LLC (Delayed Draw) (d) ​ L ​ 4.50 % ​ 9.23 % ​ 12/1/2027 ​ 388 ​ ​ — Accelerate Auto Works Intermediate, LLC (Revolver) (d) ​ L ​ 4.50 % ​ 9.23 % ​ 12/1/2027 ​ 132 ​ ​ — Truck-Lite Co., LLC ​ SF ​ 6.25 % ​ 11.14 % ​ 12/14/2026 ​ 1,691 ​ ​ 1,690 Truck-Lite Co., LLC ​ SF ​ 6.25 % ​ 11.14 % ​ 12/14/2026 ​ 251 ​ ​ 250 Truck-Lite Co., LLC ​ SF ​ 6.25 % ​ 11.14 % ​ 12/14/2026 ​ 43 ​ ​ 43 Wheel Pros, Inc. ​ L ​ 4.50 % ​ 8.82 % ​ 5/11/2028 ​ 1,932 ​ ​ 1,321 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,828 ​ ​ 4,690 Beverage, Food & Tobacco ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CBC Restaurant Corp. ​ n/a ​ n/a ​ ​ 5.00 % PIK (e) ​ n/a (f) 1,066 ​ ​ 415 SW Ingredients Holdings, LLC ​ L ​ 4.75 % ​ 9.13 % ​ 7/3/2025 ​ 3,581 ​ ​ 3,581 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,647 ​ ​ 3,996 Capital Equipment ​ ​ ​ ​ ​ ​ Analogic Corporation L 5.25 % ​ 9.66 % ​ 6/24/2024 4,703 ​ 4,433 DS Parent, Inc. ​ L ​ 5.75 % ​ 9.92 % ​ 12/8/2028 ​ 2,850 ​ ​ 2,725 MacQueen Equipment, LLC ​ L ​ 5.25 % ​ 9.98 % ​ 1/7/2028 ​ 2,096 ​ ​ 2,096 MacQueen Equipment, LLC (Delayed Draw) (d) ​ L ​ 5.25 % ​ 9.98 % ​ 1/7/2028 ​ 592 ​ ​ 69 MacQueen Equipment, LLC (Revolver) (d) L 5.25 % ​ 9.98 % ​ 1/7/2028 296 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,537 ​ ​ 9,323 Chemicals, Plastics & Rubber ​ ​ ​ ​ ​ Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group) L ​ 7.00 % ​ 11.39 % ​ 6/15/2023 1,139 ​ 1,132 TJC Spartech Acquisition Corp. ​ L ​ 4.75 % ​ 8.53 % ​ 5/5/2028 ​ 4,253 ​ ​ 4,131 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,392 ​ ​ 5,263 Construction & Building ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Cook & Boardman Group LLC SF ​ 5.75 % ​ 9.99 % ​ 10/20/2025 2,879 ​ 2,458 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,879 ​ ​ 2,458 Consumer Goods: Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ International Textile Group, Inc. L ​ 5.00 % ​ 9.21 % ​ 5/1/2024 1,664 ​ 1,166 Runner Buyer INC. L ​ 5.50 % ​ 10.23 % ​ 10/23/2028 2,978 ​ 2,114 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,642 ​ ​ 3,280 Consumer Goods: Non-Durable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PH Beauty Holdings III, INC. L ​ 5.00 % ​ 9.73 % ​ 9/26/2025 2,393 ​ 1,950 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2,393 ​ ​ 1,950 Containers, Packaging & Glass ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liqui-Box Holdings, Inc. L ​ 4.50 % ​ 9.23 % ​ 2/26/2027 4,225 ​ 4,186 Polychem Acquisition, LLC L ​ 5.00 % ​ 9.38 % ​ 3/17/2025 2,888 ​ 2,888 PVHC Holding Corp L 4.75 % ​ 9.48 % ​ 8/5/2024 3,184 ​ 3,072 ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,297 ​ ​ 10,146 Energy: Oil & Gas ​ ​ ​ ​ Drilling Info Holdings, Inc. L 4.25 % ​ 8.63 % ​ 7/30/2025 4,469 ​ 4,313 Offen, Inc. L 5.00 % ​ 9.38 % ​ 6/22/2026 2,249 ​ 2,249 Offen, Inc. L 5.00 % ​ 9.38 % ​ 6/22/2026 867 ​ 867 ​ ​ ​ ​ ​ ​ ​ ​ 7,585 ​ ​ 7,429 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Portfolio Company (a) ​ Index (b) ​ Spread (b) ​ Interest Rate (b) ​ Maturity ​ Principal ​ Fair Value FIRE: Finance ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Harbour Benefit Holdings, Inc. ​ L ​ 5.25 % 9.98 % ​ 12/13/2024 ​ 2,901 ​ $ 2,898 Harbour Benefit Holdings, Inc. ​ L ​ 5.25 % 9.63 % ​ 12/13/2024 ​ 61 ​ ​ 61 Minotaur Acquisition, Inc. ​ SF ​ 4.75 % 9.17 % ​ 3/27/2026 ​ 4,857 ​ ​ 4,656 TEAM Public Choices, LLC ​ L ​ 5.00 % 9.93 % ​ 12/17/2027 ​ 2,955 ​ ​ 2,822 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,774 ​ ​ 10,437 FIRE: Real Estate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Avison Young (USA) Inc. (c) ​ SF ​ 5.75 % 10.19 % ​ 1/30/2026 ​ 4,800 ​ ​ 4,020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,800 ​ ​ 4,020 Healthcare & Pharmaceuticals ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cano Health, LLC ​ SF ​ 4.00 % 8.42 % ​ 11/23/2027 ​ 1,970 ​ ​ 1,572 HAH Group Holding Company LLC ​ SF ​ 5.00 % 9.43 % ​ 10/29/2027 ​ 2,978 ​ ​ 2,847 LSCS Holdings, Inc. ​ L ​ 4.50 % 8.88 % ​ 12/15/2028 ​ 1,828 ​ ​ 1,751 Natus Medical Incorporated ​ SF ​ 5.50 % 8.68 % ​ 7/20/2029 ​ 5,000 ​ ​ 4,650 Paragon Healthcare, Inc. ​ SF ​ 5.75 % 9.81 % ​ 1/19/2027 ​ 2,127 ​ ​ 2,109 Paragon Healthcare, Inc. (Delayed Draw) (d) ​ SF ​ 5.75 % 10.06 % ​ 1/19/2027 ​ 366 ​ ​ 242 Paragon Healthcare, Inc. (Revolver) (d) ​ SF ​ 5.75 % 10.26 % ​ 1/19/2027 ​ 490 ​ ​ 61 Radiology Partners, Inc. ​ L ​ 4.25 % 8.64 % ​ 7/9/2025 ​ 4,760 ​ ​ 4,018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 19,519 ​ ​ 17,250 High Tech Industries ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corel Inc. (c) ​ L ​ 5.00 % 9.73 % ​ 7/2/2026 ​ 3,600 ​ ​ 3,365 Lightbox Intermediate, L.P. ​ L ​ 5.00 % 9.73 % ​ 5/11/2026 ​ 4,825 ​ ​ 4,656 TGG TS Acquisition Company ​ L ​ 6.50 % 10.88 % ​ 12/12/2025 ​ 3,190 ​ ​ 3,143 ​ ​ ​ ​ ​ ​ ​ ​ 11,615 ​ ​ 11,164 Hotels, Gaming & Leisure ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Excel Fitness Holdings, Inc. ​ SF ​ 5.25 % 10.29 % ​ 4/27/2029 ​ 4,364 ​ ​ 4,102 Excel Fitness Holdings, Inc. (Revolver) (d) ​ SF ​ 5.25 % 9.67 % ​ 4/28/2028 ​ 625 ​ ​ 306 North Haven Spartan US Holdco, LLC ​ SF ​ 6.25 % 10.71 % ​ 6/6/2025 ​ 2,280 ​ ​ 2,202 Tait LLC ​ L ​ 5.00 % 8.75 % ​ 3/28/2025 ​ 4,083 ​ ​ 3,972 Tait LLC (Revolver) (d) ​ P ​ 4.00 % 10.25 % ​ 3/28/2025 ​ 769 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 12,121 ​ ​ 10,582 Media: Advertising, Printing & Publishing ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cadent, LLC ​ L ​ 6.50 % 11.23 % ​ 9/11/2025 ​ 4,237 ​ ​ 4,131 Cadent, LLC (Revolver) (d) ​ L ​ 6.50 % 11.23 % ​ 9/11/2025 ​ 167 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,404 ​ ​ 4,131 Media: Diversified & Production ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Research Now Group, Inc. and Survey Sampling International, LLC ​ L ​ 5.50 % 8.84 % ​ 12/20/2024 ​ 6,650 ​ ​ 5,035 STATS Intermediate Holdings, LLC ​ L ​ 5.25 % 9.90 % ​ 7/10/2026 ​ 4,850 ​ ​ 4,498 TA TT Buyer, LLC ​ SF ​ 5.00 % 8.98 % ​ 3/30/2029 ​ 3,325 ​ ​ 3,242 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 14,825 ​ ​ 12,775 Services: Business ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ AQ Carver Buyer, Inc. ​ L ​ 5.00 % 9.38 % ​ 9/23/2025 ​ 4,838 ​ ​ 4,834 CHA Holdings, Inc ​ L ​ 4.50 % 9.23 % ​ 4/10/2025 ​ 1,960 ​ ​ 1,886 CHA Holdings, Inc ​ L ​ 4.50 % 9.23 % ​ 4/10/2025 ​ 413 ​ ​ 398 Eliassen Group, LLC ​ SF ​ 5.50 % 10.08 % ​ 4/14/2028 ​ 3,251 ​ ​ 3,194 Eliassen Group, LLC (Delayed Draw) (d) ​ SF ​ 5.50 % 8.88 % ​ 4/14/2028 ​ 740 ​ ​ 109 Engage2Excel, Inc. ​ L ​ 7.25 % 11.98 % ​ 3/7/2023 ​ 4,283 ​ ​ 4,242 Engage2Excel, Inc. ​ L ​ 7.25 % 11.98 % ​ 3/7/2023 ​ 773 ​ ​ 766 Engage2Excel, Inc. (Revolver) (d) ​ P ​ 6.25 % 13.75 % ​ 3/7/2023 ​ 554 ​ ​ 509 Orbit Purchaser LLC ​ L ​ 4.50 % 9.23 % ​ 10/21/2024 ​ 2,406 ​ ​ 2,190 Orbit Purchaser LLC ​ L ​ 4.50 % 9.23 % ​ 10/21/2024 ​ 1,858 ​ ​ 1,691 Orbit Purchaser LLC ​ L ​ 4.50 % 9.23 % ​ 10/21/2024 ​ 543 ​ ​ 494 ​ ​ ​ ​ ​ ​ 9.80 % Cash/ ​ ​ ​ ​ ​ ​ ​ Output Services Group, Inc. ​ SF ​ 6.75 % 1.50 % PIK ​ 6/29/2026 ​ 4,807 ​ ​ 3,275 Secretariat Advisors LLC ​ L ​ 4.75 % 9.48 % ​ 12/29/2028 ​ 1,693 ​ ​ 1,634 Secretariat Advisors LLC ​ L ​ 4.75 % 9.48 % ​ 12/29/2028 ​ 270 ​ ​ 260 SIRVA Worldwide Inc. ​ L ​ 5.50 % 10.23 % ​ 8/4/2025 ​ 1,800 ​ ​ 1,606 Teneo Holdings LLC ​ SF ​ 5.25 % 9.67 % ​ 7/11/2025 ​ 4,837 ​ ​ 4,668 The Kleinfelder Group, Inc. ​ L ​ 5.25 % 9.98 % ​ 11/29/2024 ​ 2,362 ​ ​ 2,362 ​ ​ ​ ​ ​ ​ ​ ​ 37,388 ​ ​ 34,118 Services: Consumer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 360Holdco, Inc. ​ SF ​ 5.00 % 9.42 % ​ 8/2/2025 ​ 2,145 ​ ​ 2,145 360Holdco, Inc. (Delayed Draw) (d) ​ SF ​ 5.00 % 9.42 % ​ 8/2/2025 ​ 827 ​ ​ 252 Laseraway Intermediate Holdings II, LLC ​ L ​ 5.75 % 9.76 % ​ 10/14/2027 ​ 2,200 ​ ​ 2,161 McKissock Investment Holdings, LLC ​ SF ​ 5.00 % 8.87 % ​ 3/9/2029 ​ 2,481 ​ ​ 2,322 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,653 ​ ​ 6,880 Telecommunications ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Intermedia Holdings, Inc. ​ L ​ 6.00 % 10.38 % ​ 7/21/2025 ​ 1,760 ​ ​ 1,360 Mavenir Systems, Inc. ​ L ​ 4.75 % 9.42 % ​ 8/18/2028 ​ 1,654 ​ ​ 1,350 Sandvine Corporation ​ L ​ 4.50 % 8.88 % ​ 10/31/2025 ​ 2,000 ​ ​ 1,904 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5,414 ​ ​ 4,614 Transportation: Cargo ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Keystone Purchaser, LLC ​ L ​ 5.50 % 10.60 % ​ 5/7/2027 ​ 4,955 ​ ​ 4,955 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4,955 ​ ​ 4,955 Utilities: Oil & Gas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Dresser Utility Solutions, LLC (fka NGS US Finco, LLC) ​ L ​ 4.25 % 8.63 % ​ 10/1/2025 ​ 1,678 ​ ​ 1,619 Dresser Utility Solutions, LLC (fka NGS US Finco, LLC) ​ L ​ 5.25 % 9.63 % ​ 10/1/2025 ​ 245 ​ ​ 239 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1,923 ​ ​ 1,858 Wholesale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HALO Buyer, Inc. ​ L ​ 4.50 % 8.88 % ​ 6/30/2025 ​ 4,774 ​ ​ 4,219 ​ ​ ​ ​ ​ ​ ​ ​ 4,774 ​ ​ 4,219 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TOTAL INVESTMENTS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 183,150 (a) All investments are U.S. companies unless otherwise noted. (b) The majority of investments bear interest at a rate that may be determined by reference to the London Interbank Offered Rate (“LIBOR” or “L”), Secured Overnight Financing Rate (“SOFR” or “SF”) or Prime (“P”) which reset daily, monthly, quarterly or semiannually. The Company has provided the spread over LIBOR, SOFR or Prime and the current contractual rate of interest in effect at December 31, 2022. Certain investments may be subject to an interest rate floor or cap. Certain investments contain a Payment-in-kind (“PIK”) provision. (c) This is an international company. (d) All or a portion of this commitment was unfunded as of December 31, 2022. As such, interest is earned only on the funded portion of this commitment. Principal reflects the commitment outstanding. (e) This position was on non-accrual status as of December 31, 2022, meaning that the Company has ceased accruing interest income on the position. (f) This is a demand note with no stated maturity.
Schedule of summarized financial information for SLF	​ Below is certain summarized financial information for SLF as of September 30, 2023 and December 31, 2022 and for the three and nine months ended September 30, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 December 31, 2022 ​ ​ (unaudited) ​ ​ ​ Assets ​ ​ Investments, at fair value ​ $ 148,152 ​ $ 183,150 Cash ​ 2,104 ​ 1,608 Restricted cash ​ 5,523 ​ 6,454 Interest receivable ​ 1,246 ​ 1,613 Other assets ​ 1,642 ​ 5 Total assets ​ $ 158,667 ​ $ 192,830 Liabilities ​ ​ ​ Revolving credit facility ​ $ 92,064 ​ $ 122,215 Less: Unamortized deferred financing costs ​ (919) ​ (1,518) Total debt, less unamortized deferred financing costs ​ 91,145 ​ 120,697 Interest payable ​ 621 ​ 769 Accounts payable and accrued expenses ​ 363 ​ 346 Total liabilities ​ 92,129 ​ 121,812 Members’ capital ​ 66,538 ​ 71,018 Total liabilities and members’ capital ​ $ 158,667 ​ $ 192,830 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, ​ Nine months ended September 30, ​ 2023 2022 2023 2022 ​ ​ (unaudited) ​ (unaudited) Investment income: ​ ​ ​ ​ Interest income ​ $ 3,936 ​ $ 4,075 ​ $ 14,017 ​ $ 10,593 Total investment income ​ 3,936 ​ 4,075 ​ 14,017 ​ 10,593 Expenses: ​ ​ ​ ​ ​ ​ ​ ​ Interest and other debt financing expenses ​ 2,194 ​ 1,669 ​ 6,848 ​ 3,866 Professional fees ​ 146 ​ 203 ​ 549 ​ 580 Total expenses ​ 2,340 ​ 1,872 ​ 7,397 ​ 4,446 Net investment income (loss) ​ 1,596 ​ 2,203 ​ 6,620 ​ 6,147 Net gain (loss): ​ ​ ​ ​ ​ ​ ​ ​ Net realized gain (loss) on investments ​ ​ (274) ​ ​ — ​ ​ (814) ​ ​ — Net change in unrealized gain (loss) on investments ​ (2,073) ​ (2,416) ​ (4,886) ​ (10,909) Net gain (loss) ​ (2,347) ​ (2,416) ​ (5,700) ​ (10,909) Net increase (decrease) in members’ capital ​ $ (751) ​ $ (213) ​ $ 920 ​ $ (4,762) ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Measurements
Schedule of fair value measurements of investments and foreign currency forward contracts, by major class according to the fair value hierarchy	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements September 30, 2023 ​ Level 1 ​ Level 2 ​ Level 3 ​ Total Investments: ​ ​ ​ ​ Senior secured loans ​ $ — ​ $ — ​ $ 416,316 ​ $ 416,316 Unitranche secured loans ​ — ​ — ​ 13,548 ​ 13,548 Junior secured loans ​ — ​ — ​ 27,425 ​ 27,425 Equity securities ​ 229 ​ — ​ 27,497 ​ 27,726 Investments measured at NAV (1) (2) ​ — ​ — ​ — ​ 33,269 Total investments ​ $ 229 ​ $ — ​ $ 484,786 ​ $ 518,284 Foreign currency forward contracts asset (liability) ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements December 31, 2022 ​ Level 1 ​ Level 2 ​ Level 3 ​ Total Investments: ​ ​ ​ ​ Senior secured loans ​ $ — ​ $ — ​ $ 434,023 ​ $ 434,023 Unitranche secured loans ​ — ​ — ​ 20,633 ​ 20,633 Junior secured loans ​ — ​ — ​ 22,193 ​ 22,193 Equity securities ​ 294 ​ — ​ 28,388 ​ 28,682 Investments measured at NAV (1) (2) ​ — ​ — ​ — ​ 35,509 Total investments ​ $ 294 ​ $ — ​ $ 505,237 ​ $ 541,040 Foreign currency forward contracts asset (liability) ​ $ — ​ $ 1,507 ​ $ — ​ $ 1,507 (1) Certain investments that are measured at fair value using the NAV have not been categorized in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the consolidated statements of assets and liabilities. (2) Represents the Company’s investment in LLC equity interests in SLF. The fair value of this investment has been determined using the NAV of the Company’s ownership interest in SLF’s members’ capital.
Schedule of reconciliation of beginning and ending balances for investments at fair value that use Level 3 inputs	The following tables provide a reconciliation of the beginning and ending balances for investments at fair value that use Level 3 inputs for the three and nine months ended September 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of June 30, 2023 $ 415,873 $ 13,400 $ 25,307 $ 26,034 $ 480,614 Net realized gain (loss) on investments ​ — ​ — ​ — ​ 6 ​ 6 Net change in unrealized gain (loss) on investments ​ (3,554) ​ (43) ​ (690) ​ (100) ​ (4,387) Purchases of investments and other adjustments to cost (1) ​ 13,259 ​ 210 ​ 1,746 ​ 83 ​ 15,298 Proceeds from principal payments and sales of investments (2) ​ (5,971) ​ (19) ​ (749) ​ (6) ​ (6,745) Reclassifications (3) ​ ​ (3,291) ​ ​ — ​ ​ 1,811 ​ ​ 1,480 ​ ​ — Balance as of September 30, 2023 ​ $ 416,316 ​ $ 13,548 ​ $ 27,425 ​ $ 27,497 ​ $ 484,786 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of December 31, 2022 $ 434,023 $ 20,633 $ 22,193 $ 28,388 $ 505,237 Net realized gain (loss) on investments ​ (9,787) ​ (24,768) ​ — ​ (4,465) ​ (39,020) Net change in unrealized gain (loss) on investments ​ (2,734) ​ 24,746 ​ (1,743) ​ 1,793 ​ 22,062 Purchases of investments and other adjustments to cost (1) ​ 54,107 ​ 295 ​ 4,564 ​ 1,304 ​ 60,270 Proceeds from principal payments and sales of investments (2) ​ (53,234) ​ (7,358) ​ (2,168) ​ (1,003) ​ (63,763) Reclassifications (3) ​ ​ (6,059) ​ ​ — ​ ​ 4,579 ​ ​ 1,480 ​ ​ — Balance as of September 30, 2023 ​ $ 416,316 ​ $ 13,548 ​ $ 27,425 ​ $ 27,497 ​ $ 484,786 (1) Includes purchases of new investments, effects of refinancing and restructurings, premium and discount accretion and amortization and PIK interest. (2) Represents net proceeds from investments sold and principal paydowns received. (3) Represents non-cash reclassification of investment type due to a restructuring. The following tables provide a reconciliation of the beginning and ending balances for investments at fair value that use Level 3 inputs for the three and nine months ended September 30, 2022. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of June 30, 2022 $ 415,244 $ 34,114 $ 19,745 $ 28,837 $ 497,940 Net realized gain (loss) on investments ​ (1,672) ​ — ​ (1) ​ 6 ​ (1,667) Net change in unrealized gain (loss) on investments ​ (3,788) ​ 10 ​ 1,314 ​ (2,604) ​ (5,068) Purchases of investments and other adjustments to cost (1) ​ 52,370 ​ 15 ​ 368 ​ 162 ​ 52,915 Proceeds from principal payments and sales of investments (2) ​ (59,925) ​ (13,096) ​ — ​ (6) ​ (73,027) Balance as of September 30, 2022 ​ $ 402,229 ​ $ 21,043 ​ $ 21,426 ​ $ 26,395 ​ $ 471,093 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments ​ ​ Senior ​ Unitranche ​ Junior ​ Equity ​ Total Level 3 ​ ​ secured loans ​ secured loans ​ secured loans ​ securities ​ investments Balance as of December 31, 2021 $ 423,700 $ 51,494 $ 14,364 $ 29,969 $ 519,527 Net realized gain (loss) on investments ​ (1,693) ​ (94) ​ (1) ​ 38 ​ (1,750) Net change in unrealized gain (loss) on investments ​ (8,838) ​ (5,146) ​ 992 ​ (4,114) ​ (17,106) Purchases of investments and other adjustments to cost (1) ​ 88,950 ​ 3,253 ​ 6,071 ​ 831 ​ 99,105 Proceeds from principal payments and sales of investments (2) ​ (99,890) ​ (28,464) ​ — ​ (329) ​ (128,683) Balance as of September 30, 2022 ​ $ 402,229 ​ $ 21,043 ​ $ 21,426 ​ $ 26,395 ​ $ 471,093 (1) Includes purchases of new investments, effects of refinancing and restructurings, premium and discount accretion and amortization and PIK interest. (2) Represents net proceeds from investments sold and principal paydowns received.
Schedule of valuation techniques and significant unobservable inputs used in recurring Level 3 fair value measurements of assets	The valuation techniques and significant unobservable inputs used in recurring Level 3 fair value measurements of assets as of September 30, 2023 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unobservable ​ Average ​ Range ​ Fair Value Valuation Technique Input Mean Minimum Maximum Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior secured loans ​ $ 270,084 Discounted cash flow EBITDA multiples 10.5 x 5.8 x 22.0 x ​ ​ ​ ​ ​ Market yields ​ 13.7 % 9.5 % 29.3 % Senior secured loans ​ 108,565 Discounted cash flow Revenue multiples 5.5 x 0.8 x 11.5 x ​ ​ ​ ​ ​ Market yields ​ 12.6 % 11.0 % 17.5 % Senior secured loans ​ 18,020 Enterprise value Book value multiples 1.3 x 1.3 x 1.3 x Senior secured loans ​ 9,191 Liquidation Probability weighting of alternative outcomes 95.8 % 32.4 % 100.0 % Senior secured loans ​ ​ 6,752 ​ Enterprise value ​ Revenue multiples ​ 2.0 x 2.0 x 2.0 x Senior secured loans ​ 3,104 Enterprise value EBITDA multiples 8.2 x 5.5 x 8.3 x Unitranche secured loans ​ 9,828 Discounted cash flow EBITDA multiples 9.0 x 9.0 x 9.0 x ​ ​ ​ ​ Market yields 13.1 % 11.8 % 13.5 % Unitranche secured loans ​ 3,720 Discounted cash flow ​ Revenue multiples ​ 9.0 x 6.0 x 12.8 x ​ ​ ​ ​ Market yields 13.0 % 12.6 % 13.4 % Junior secured loans ​ 21,338 Discounted cash flow Market yields 13.7 % 12.9 % 15.6 % Junior secured loans ​ 2,574 Enterprise value Revenue multiples 2.0 x 2.0 x 2.0 x Junior secured loans ​ ​ 2,085 ​ Liquidation ​ Probability weighting of alternative outcomes ​ 250.3 % 0.0 % 250.3 % Junior secured loans ​ ​ 1,428 ​ Discounted cash flow ​ Revenue multiples ​ 0.4 x 0.1 x 0.8 x ​ ​ ​ ​ ​ ​ ​ Market yields ​ 13.3 % 12.0 % 16.1 % Equity securities ​ 18,542 Enterprise value EBITDA multiples 9.2 x 5.5 x 19.3 x Equity securities ​ 5,736 Enterprise value Revenue multiples 2.1 x 0.7 x 11.5 x Equity securities ​ 2,442 Option pricing model Volatility 63.0 % 32.0 % 72.5 % Equity securities ​ 357 Discounted cash flow EBITDA multiples 6.0 x 6.0 x 6.0 x ​ ​ ​ ​ ​ ​ ​ Market yields ​ 27.5 % 27.5 % 27.5 % Total Level 3 Assets ​ $ 483,766 (1) ​ ​ ​ ​ ​ ​ (1) Excludes investments of $ 1,020 at fair value where valuation (unadjusted) is obtained from a third-party pricing service or broker quote for which such disclosure is not required. The valuation techniques and significant unobservable inputs used in recurring Level 3 fair value measurements of assets as of December 31, 2022 were as follows : ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Fair ​ ​ ​ Unobservable ​ Average ​ Range ​ ​ Value ​ Valuation Technique ​ Input ​ Mean ​ Minimum ​ Maximum Assets: ​ ​ Senior secured loans ​ $ 276,433 Discounted cash flow EBITDA multiples 9.3 x 3.8 x 18.6 x ​ ​ Market yields 12.4 % 8.7 % 22.3 % Senior secured loans ​ 130,199 Discounted cash flow Revenue multiples 4.4 x 0.2 x 12.3 x ​ ​ ​ ​ ​ Market yields ​ 13.4 % 10.0 % 22.0 % Senior secured loans ​ 19,546 Enterprise value Book value multiples 1.2 x 1.2 x 1.2 x Senior secured loans ​ 5,706 Enterprise value Revenue multiples 2.5 x 2.5 x 2.5 x Senior secured loans ​ 1,488 Liquidation Probability weighting of alternative outcomes 71.3 % 29.1 % 100.0 % Senior secured loans ​ 80 Enterprise value EBITDA multiples 8.0 x 8.0 x 8.0 x Unitranche secured loans ​ 17,019 Discounted cash flow EBITDA multiples 8.8 x 8.8 x 8.8 x ​ ​ ​ ​ ​ ​ Market yields 11.2 % 9.1 % 13.0 % Unitranche secured loans ​ 3,614 Discounted cash flow Revenue multiples 8.9 x 5.8 x 12.5 x ​ ​ ​ ​ ​ ​ ​ Market yields ​ 11.9 % 11.6 % 12.1 % Junior secured loans ​ 20,311 Discounted cash flow Market yields 13.6 % 12.3 % 20.4 % Junior secured loans ​ 1,882 Liquidation Probability weighting of alternative outcomes 225.8 % 225.8 % 225.8 % Equity securities ​ 16,630 Enterprise value EBITDA multiples 9.0 x 3.8 x 16.0 x Equity securities ​ 7,502 Enterprise value Revenue multiples 2.3 x 0.2 x 12.3 x Equity securities ​ 2,173 Option pricing model Volatility 66.6 % 49.4 % 70.0 % Equity securities ​ 397 Discounted cash flow EBITDA multiples 7.0 x 7.0 x 7.0 x Total Level 3 Assets ​ $ 502,980 (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) Excludes investments of $2,257 at fair value where valuation (unadjusted) is obtained from a third-party pricing service or broker quote for which such disclosure is not required.

Transactions with Affiliated _2

Transactions with Affiliated Companies (Tables)	9 Months Ended
	Sep. 30, 2023
Transactions with Affiliated Companies
Schedule of transactions with affiliated companies	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Sales and ​ PIK ​ ​ ​ ​ ​ ​ ​ Net ​ ​ ​ ​ ​ Fair value at ​ Transfers ​ Purchases ​ paydowns ​ interest ​ Discount ​ Net realized ​ unrealized ​ Fair value at Portfolio Company December 31, 2022 in (out) (cost) (cost) (cost) accretion gain (loss) gain (loss) September 30, 2023 Non-Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ American Community Homes, Inc. ​ $ 8,953 ​ $ — ​ $ — ​ $ — ​ $ 1,165 ​ $ — ​ $ — ​ $ (1,925) ​ $ 8,193 American Community Homes, Inc. ​ ​ 4,258 ​ ​ — ​ ​ — ​ ​ — ​ ​ 757 ​ ​ — ​ ​ — ​ ​ (985) ​ ​ 4,030 American Community Homes, Inc. ​ ​ 543 ​ ​ — ​ ​ — ​ ​ — ​ ​ 70 ​ ​ — ​ ​ — ​ ​ (116) ​ ​ 497 American Community Homes, Inc. ​ ​ 1,996 ​ ​ — ​ ​ — ​ ​ — ​ ​ 259 ​ ​ — ​ ​ — ​ ​ (429) ​ ​ 1,826 American Community Homes, Inc. ​ ​ 3,694 ​ ​ — ​ ​ — ​ ​ — ​ ​ 481 ​ ​ — ​ ​ — ​ ​ (794) ​ ​ 3,381 American Community Homes, Inc. ​ ​ 17 ​ ​ — ​ ​ — ​ ​ — ​ ​ 2 ​ ​ — ​ ​ — ​ ​ (3) ​ ​ 16 American Community Homes, Inc. ​ ​ 85 ​ ​ — ​ ​ — ​ ​ — ​ ​ 11 ​ ​ — ​ ​ — ​ ​ (19) ​ ​ 77 American Community Homes, Inc. (Revolver) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — American Community Homes, Inc. (4,940 shares of common stock) (1) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 19,546 ​ ​ — ​ ​ — ​ ​ — ​ ​ 2,745 ​ ​ — ​ ​ — ​ ​ (4,271) ​ ​ 18,020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ascent Midco, LLC ​ ​ 6,217 ​ — ​ ​ — ​ ​ (6,175) ​ ​ — ​ ​ 16 ​ ​ — ​ ​ (58) ​ ​ — Ascent Midco, LLC (Revolver) ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Ascent Midco, LLC (2,032,258 Class A units) ​ ​ 1,969 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (55) ​ ​ 1,914 ​ ​ ​ 8,186 ​ — ​ ​ — ​ ​ (6,175) ​ ​ — ​ ​ 16 ​ ​ — ​ ​ (113) ​ ​ 1,914 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C Parent Holdings, LLC. ​ 146 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (146) ​ ​ — C Parent Holdings, LLC. (58,779 shares of common stock) (2) ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 146 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (146) ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Familia Dental Group Holdings, LLC (1,212 Class A units) ​ ​ 2,625 ​ — ​ ​ 122 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (396) ​ ​ 2,351 ​ ​ ​ 2,625 ​ — ​ ​ 122 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (396) ​ ​ 2,351 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HFZ Capital Group, LLC ​ ​ 16,159 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 803 ​ ​ 16,962 HFZ Capital Group, LLC ​ ​ 5,805 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 289 ​ ​ 6,094 MC Asset Management (Corporate), LLC ​ ​ 8,421 ​ — ​ ​ — ​ ​ — ​ ​ 1,311 ​ ​ — ​ ​ — ​ ​ — ​ ​ 9,732 MC Asset Management (Corporate), LLC ​ ​ 1,000 ​ — ​ ​ 1,586 ​ ​ — ​ ​ 317 ​ ​ — ​ ​ — ​ ​ — ​ ​ 2,903 MC Asset Management (Corporate), LLC (15.9% of interests) ​ ​ 1,291 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (59) ​ ​ 1,232 ​ ​ ​ 32,676 ​ — ​ ​ 1,586 ​ ​ — ​ ​ 1,628 ​ ​ — ​ ​ — ​ ​ 1,033 ​ ​ 36,923 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mnine Holdings, Inc. ​ ​ — ​ ​ — ​ ​ 105 ​ ​ (52) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 53 Mnine Holdings, Inc. ​ ​ 5,492 ​ — ​ ​ — ​ ​ — ​ ​ 569 ​ ​ 12 ​ ​ — ​ ​ (14) ​ ​ 6,059 Mnine Holdings, Inc. ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Mnine Holdings, Inc. (Revolver) ​ ​ 214 ​ ​ — ​ ​ 308 ​ ​ — ​ ​ 11 ​ ​ — ​ ​ — ​ ​ — ​ ​ 533 Mnine Holdings, Inc. (6,400 Class B units) ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 5,706 ​ — ​ ​ 413 ​ ​ (52) ​ ​ 580 ​ ​ 12 ​ ​ — ​ ​ (14) ​ ​ 6,645 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NECB Collections, LLC (Revolver) ​ ​ 382 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 42 ​ ​ 424 NECB Collections, LLC, LLC (20.8% of LLC units) ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 382 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 42 ​ ​ 424 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Second Avenue SFR Holdings II LLC (Revolver) (3) ​ ​ 4,755 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 4,761 ​ ​ ​ 4,755 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 4,761 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SFR Holdco, LLC (Junior secured loan) ​ ​ 5,850 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 508 ​ ​ 6,358 SFR Holdco, LLC (24.4% of interests) ​ ​ 3,900 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 339 ​ ​ 4,239 ​ ​ ​ 9,750 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 847 ​ ​ 10,597 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TJ Management HoldCo, LLC (Revolver) ​ ​ 80 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 80 TJ Management HoldCo, LLC (16 shares of common stock) ​ ​ 2,766 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 417 ​ ​ 3,183 ​ ​ ​ 2,846 ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 417 ​ ​ 3,263 Total non-controlled affiliate company investments ​ $ 86,618 ​ $ — ​ $ 2,121 ​ $ (6,227) ​ $ 4,953 ​ $ 28 ​ $ — ​ $ (2,595) ​ $ 84,898 Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MRCC Senior Loan Fund I, LLC ​ $ 35,509 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (2,240) ​ $ 33,269 ​ ​ ​ 35,509 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (2,240) ​ ​ 33,269 Total controlled affiliate company investments ​ $ 35,509 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (2,240) ​ $ 33,269 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value at ​ ​ ​ ​ Sales and PIK ​ ​ Net Net Fair value at ​ ​ December 31, ​ Transfers ​ Purchases ​ paydowns ​ interest ​ Discount ​ realized ​ unrealized ​ September Portfolio Company ​ 2021 ​ in (out) ​ (cost) ​ (cost) ​ (cost) ​ accretion ​ gain (loss) ​ gain (loss) ​ 30, 2022 Non-controlled affiliate company investment: ​ ​ ​ ​ ​ ​ ​ ​ ​ American Community Homes, Inc. ​ $ 10,457 ​ $ — ​ $ — ​ $ — ​ $ 466 ​ $ — ​ $ — ​ $ (1,889) ​ $ 9,034 American Community Homes, Inc. ​ 4,753 ​ — ​ — ​ — ​ 384 ​ — ​ — ​ (888) ​ 4,249 American Community Homes, Inc. ​ 634 ​ — ​ — ​ — ​ 28 ​ — ​ — ​ (114) ​ 548 American Community Homes, Inc. ​ 3,164 ​ — ​ — ​ — ​ 104 ​ — ​ — ​ (1,254) ​ 2,014 American Community Homes, Inc. ​ 4,357 ​ — ​ — ​ — ​ 192 ​ — ​ — ​ (821) ​ 3,728 American Community Homes, Inc. ​ 20 ​ — ​ — ​ — ​ 1 ​ — ​ — ​ (3) ​ 18 American Community Homes, Inc. ​ ​ 99 ​ ​ — ​ ​ — ​ ​ — ​ ​ 4 ​ ​ — ​ ​ — ​ ​ (18) ​ ​ 85 American Community Homes, Inc. (Revolver) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — American Community Homes, Inc. (warrant to purchase up to 22.3% of the equity) (1) ​ 264 ​ — ​ — ​ — ​ — ​ — ​ — ​ (264) ​ — ​ ​ 23,748 ​ — ​ — ​ — ​ 1,179 ​ — ​ — ​ (5,251) ​ 19,676 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ascent Midco, LLC ​ 6,392 ​ — ​ — ​ (130) ​ — ​ 19 ​ — ​ (121) ​ 6,160 Ascent Midco, LLC (Revolver) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — Ascent Midco, LLC ( 2,032,258 Class A units) ​ 2,554 ​ — ​ — ​ — ​ — ​ — ​ — ​ (1,136) ​ 1,418 ​ ​ 8,946 ​ — ​ — ​ (130) ​ — ​ 19 ​ — ​ (1,257) ​ 7,578 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Curion Holdings, LLC (2) ​ 4,561 ​ — ​ — ​ (4,497) ​ — ​ — ​ — ​ 82 ​ 146 Curion Holdings, LLC (Revolver) (2) ​ 550 ​ — ​ 92 ​ (620) ​ — ​ — ​ — ​ (22) ​ — Curion Holdings, LLC (Junior secured loan) (2) ​ — ​ — ​ — ​ — ​ — ​ — ​ (1) ​ 1 ​ — Curion Holdings, LLC (Junior secured loan) (2) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — Curion Holdings, LLC ( 58,779 shares of common stock) (2) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 5,111 ​ — ​ 92 ​ (5,117) ​ — ​ — ​ (1) ​ 61 ​ 146 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Familia Dental Group Holdings, LLC ( 1,158 Class A units) ​ 1,919 ​ — ​ 183 ​ — ​ — ​ — ​ — ​ 406 ​ 2,508 ​ ​ 1,919 ​ — ​ 183 ​ — ​ — ​ — ​ — ​ 406 ​ 2,508 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HFZ Capital Group, LLC ​ 15,084 ​ — ​ — ​ — ​ — ​ — ​ — ​ 804 ​ 15,888 HFZ Capital Group, LLC ​ 5,420 ​ — ​ — ​ — ​ — ​ — ​ — ​ 288 ​ 5,708 MC Asset Management (Corporate), LLC ​ 7,154 ​ — ​ — ​ — ​ 903 ​ — ​ — ​ — ​ 8,057 MC Asset Management (Corporate), LLC (Delayed Draw) ​ 850 ​ — ​ — ​ — ​ 107 ​ — ​ — ​ — ​ 957 MC Asset Management (Corporate), LLC ( 15.9% of interests) ​ 644 ​ — ​ — ​ — ​ — ​ — ​ — ​ 107 ​ 751 ​ ​ 29,152 ​ — ​ — ​ — ​ 1,010 ​ — ​ — ​ 1,199 ​ 31,361 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mnine Holdings, Inc. ​ 5,771 ​ — ​ — ​ — ​ 230 ​ 12 ​ — ​ (12) ​ 6,001 Mnine Holdings, Inc. (Revolver) ​ ​ — ​ ​ — ​ ​ 240 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 240 Mnine Holdings, Inc. ( 6,400 Class B units) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 5,771 ​ — ​ 240 ​ — ​ 230 ​ 12 ​ — ​ (12) ​ 6,241 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NECB Collections, LLC (Revolver) ​ 632 ​ — ​ — ​ — ​ — ​ — ​ — ​ (206) ​ 426 NECB Collections, LLC ( 20.8% of LLC units) ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 632 ​ — ​ — ​ — ​ — ​ — ​ — ​ (206) ​ 426 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Second Avenue SFR Holdings II LLC (Revolver) (3) ​ ​ 2,104 ​ ​ — ​ ​ 2,681 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (18) ​ ​ 4,767 ​ ​ ​ 2,104 ​ ​ — ​ ​ 2,681 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (18) ​ ​ 4,767 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SFR Holdco, LLC (Junior secured loan) ​ ​ 5,850 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 5,850 SFR Holdco, LLC ( 24.4% of interests) ​ ​ 3,900 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 3,900 ​ ​ 9,750 ​ — ​ — ​ — ​ — ​ — ​ — ​ — ​ 9,750 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TJ Management HoldCo, LLC (Revolver) ​ — ​ — ​ 80 ​ — ​ — ​ — ​ — ​ — ​ 80 TJ Management HoldCo, LLC ( 16 shares of common stock) ​ 3,148 ​ — ​ — ​ — ​ — ​ — ​ — ​ (407) ​ 2,741 ​ ​ 3,148 ​ — ​ 80 ​ — ​ — ​ — ​ — ​ (407) ​ 2,821 Total non-controlled affiliate company investments ​ $ 90,281 ​ $ — ​ $ 3,276 ​ $ (5,247) ​ $ 2,419 ​ $ 31 ​ $ (1) ​ $ (5,485) ​ $ 85,274 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MRCC Senior Loan Fund I, LLC ​ $ 41,125 ​ $ — ​ $ 500 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (5,081) ​ $ 36,544 ​ ​ 41,125 ​ — ​ 500 ​ — ​ — ​ — ​ — ​ (5,081) ​ 36,544 Total controlled affiliate company investments ​ $ 41,125 ​ $ — ​ $ 500 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (5,081) ​ $ 36,544 (1) On December 29, 2022, the Company exercised the American Community Homes, Inc. (“ACH”) warrants held by the Company. The Company acquired 4,940 shares of ACH’s common stock, or 22.3% of the equity, in exchange for a nominal exercise price in accordance with the terms of the warrant. (2) During the year ended December 31, 2022, C Parent Holdings, LLC (fka Curion Holdings, LLC) (“Curion”) sold the underlying operating company and repaid the Company’s debt investment. The remaining fair value at December 31, 2022, represented the remaining expected escrow proceeds associated with the sale. During 2023, all expected proceeds associated with the sale were received. The Company no longer holds an equity investment in Curion as of September 30, 2023. (3) Second Avenue SFR Holdings II LLC is a related entity to SFR Holdco, LLC and is being presented as a non-controlled affiliate for that reason. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the nine months ended September 30, ​ ​ 2023 ​ 2022 ​ ​ Interest ​ Dividend ​ ​ ​ ​ Interest ​ Dividend ​ ​ ​ Portfolio Company ​ Income Income Fee Income Income Income Fee Income Non-controlled affiliate company investments: ​ ​ ​ ​ ​ ​ American Community Homes, Inc. ​ $ 1,163 ​ $ — ​ $ — ​ $ 878 ​ $ — ​ $ — American Community Homes, Inc. ​ 755 ​ — ​ — ​ 575 ​ — ​ — American Community Homes, Inc. ​ 71 ​ — ​ — ​ 53 ​ — ​ — American Community Homes, Inc. ​ 259 ​ — ​ — ​ 196 ​ — ​ — American Community Homes, Inc. ​ 480 ​ — ​ — ​ 362 ​ — ​ — American Community Homes, Inc. ​ 3 ​ — ​ — ​ 2 ​ — ​ — American Community Homes, Inc. ​ 11 ​ — ​ — ​ 8 ​ — ​ — American Community Homes, Inc. (Revolver) ​ 2 ​ — ​ — ​ 19 ​ — ​ — American Community Homes, Inc. (Common stock) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 2,744 ​ — ​ — ​ 2,093 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ascent Midco, LLC ​ 384 ​ — ​ — ​ 359 ​ — ​ — Ascent Midco, LLC (Revolver) ​ 2 ​ — ​ — ​ 3 ​ — ​ — Ascent Midco, LLC (Class A units) ​ — ​ 152 ​ — ​ — ​ 141 ​ — ​ ​ 386 ​ 152 ​ — ​ 362 ​ 141 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C Parent Holdings, LLC. ​ 172 ​ — ​ — ​ 1,766 ​ — ​ — C Parent Holdings, LLC. (Revolver) ​ ​ — ​ ​ — ​ ​ — ​ ​ 294 ​ ​ — ​ ​ — C Parent Holdings, LLC. (Common stock) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 172 ​ — ​ — ​ 2,060 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Familia Dental Group Holdings, LLC (Class A units) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ HFZ Capital Group, LLC ​ 1,749 ​ — ​ — ​ 1,430 ​ — ​ — HFZ Capital Group, LLC ​ 629 ​ — ​ — ​ 514 ​ — ​ — MC Asset Management (Corporate), LLC ​ 1,417 ​ — ​ — ​ 940 ​ — ​ — MC Asset Management (Corporate), LLC (Delayed Draw) ​ 417 ​ — ​ — ​ 111 ​ — ​ — MC Asset Management (Corporate), LLC (LLC interest) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 4,212 ​ — ​ — ​ 2,995 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mnine Holdings, Inc. ​ 600 ​ — ​ — ​ 567 ​ — ​ — Mnine Holdings, Inc. ​ ​ — ​ ​ — ​ ​ — ​ ​ 2 ​ ​ — ​ ​ — Mnine Holdings, Inc. (Revolver) ​ ​ 47 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Mnine Holdings, Inc. (Class B units) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 647 ​ — ​ — ​ 569 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NECB Collections, LLC (Revolver) ​ — ​ — ​ — ​ — ​ — ​ — NECB Collections, LLC (LLC units) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Second Avenue SFR Holdings II LLC (Revolver) ​ 434 ​ — ​ — ​ 182 ​ — ​ — ​ ​ ​ 434 ​ ​ — ​ ​ — ​ ​ 182 ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SFR Holdco, LLC (Junior secured loan) ​ 351 ​ — ​ — ​ 351 ​ — ​ — SFR Holdco, LLC (LLC interest) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 351 ​ — ​ — ​ 351 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TJ Management HoldCo, LLC (Revolver) ​ 13 ​ — ​ — ​ 9 ​ — ​ — TJ Management HoldCo, LLC (Common stock) ​ — ​ — ​ — ​ — ​ — ​ — ​ ​ 13 ​ — ​ — ​ 9 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total non-controlled affiliate company investments ​ $ 8,959 ​ $ 152 ​ $ — ​ $ 8,621 ​ $ 141 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Controlled affiliate company investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ MRCC Senior Loan Fund I, LLC ​ $ — ​ $ 2,700 ​ $ — ​ $ — ​ $ 2,700 ​ $ — ​ ​ — ​ 2,700 ​ — ​ — ​ 2,700 ​ — Total controlled affiliate company investments ​ $ — ​ $ 2,700 ​ $ — ​ $ — ​ $ 2,700 ​ $ — ​

Transactions with Related Par_2

Transactions with Related Parties (Tables)	9 Months Ended
	Sep. 30, 2023
Transactions with Related Parties
Schedule of composition of the Company's incentive fees	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, Nine months ended September 30, ​ ​ 2023 2022 ​ 2023 2022 Part one incentive fees (1) ​ $ 1,355 ​ $ 1,565 ​ $ 4,493 ​ $ 2,747 Part two incentive fees (2) ​ — ​ — ​ — ​ — Incentive fees, excluding the impact of the incentive fee waiver ​ 1,355 ​ 1,565 ​ 4,493 ​ 2,747 Incentive fee waiver (3) ​ — ​ — ​ — ​ (525) Total incentive fees, net of incentive fee waiver ​ $ 1,355 ​ $ 1,565 ​ $ 4,493 ​ $ 2,222 (1) Based on pre-incentive fee net investment income. (2) Based upon net realized and unrealized gains and losses, or capital gains. The Company accrues, but does not pay, a capital gains incentive fee in connection with any unrealized capital appreciation, as appropriate. If, on a cumulative basis, the sum of net realized gain (loss) plus net unrealized gain (loss) decreases during a period, the Company will reverse any excess capital gains incentive fee previously accrued such that the amount of capital gains incentive fee accrued is no more than 20% of the sum of net realized gain (loss) plus net unrealized gain (loss). (3) Represents part one incentive fees waived by MC Advisors.

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2023
Borrowings
Schedule of components of the Company's interest expense and other debt financing expenses, average debt outstanding balances and average stated interest rates	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, ​ ​ ​ 2023 ​ 2022 Interest expense - revolving credit facility ​ $ 3,989 ​ $ 2,186 ​ Interest expense - 2026 Notes ​ 1,555 ​ 1,555 ​ Amortization of deferred financing costs ​ 330 ​ 522 ​ Total interest and other debt financing expenses ​ $ 5,874 ​ $ 4,263 ​ Average debt outstanding ​ $ 319,759 ​ $ 292,879 ​ Average stated interest rate ​ 6.8 % 5.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, ​ 2023 2022 Interest expense - revolving credit facility ​ $ 11,536 ​ $ 5,391 ​ Interest expense - 2026 Notes ​ 4,665 ​ 4,665 ​ Interest expense - SBA debentures ​ — ​ 292 ​ Amortization of deferred financing costs ​ 977 ​ 1,613 ​ Total interest and other debt financing expenses ​ $ 17,178 ​ $ 11,961 ​ Average debt outstanding ​ $ 322,918 ​ $ 315,166 ​ Average stated interest rate ​ 6.7 % 4.3 % ​

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2023
Derivative Instruments
Schedule of information related to foreign currency forward contracts	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Notional ​ ​ ​ Amount of ​ Amount of ​ ​ ​ ​ Amount to be ​ Settlement ​ Unrealized ​ Unrealized ​ ​ Description ​ Sold Date Gain Loss Balance Sheet location of Net Amounts Foreign currency forward contract AUD 153 1/18/2023 $ 14 $ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 140 2/16/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 132 3/16/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 160 4/20/2023 ​ 14 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 121 5/16/2023 ​ 11 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 156 6/19/2023 ​ 14 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 138 7/18/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 146 8/16/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 146 9/18/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 148 10/18/2023 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 140 11/16/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 142 12/18/2023 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 150 1/17/2024 ​ 13 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 143 2/16/2024 ​ 12 ​ — Unrealized gain on foreign currency forward contracts Foreign currency forward contract AUD 15,410 3/18/2024 ​ 1,329 ​ — Unrealized gain on foreign currency forward contracts ​ ​ ​ ​ ​ ​ ​ $ 1,507 ​ $ — ​ ​

Distributions (Tables)

Distributions (Tables)	9 Months Ended
	Sep. 30, 2023
Distributions
Schedule of distributions declared	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DRIP Shares ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount ​ ​ ​ ​ DRIP ​ DRIP ​ Repurchased ​ Cost of Date ​ Record ​ Payment ​ Per ​ Cash ​ Shares ​ Shares ​ in the Open ​ DRIP Shares Declared Date Date Share Distribution Issued Value Market Repurchased Nine months ended September 30, 2023: March 1, 2023 ​ March 15, 2023 ​ March 31, 2023 ​ $ 0.25 ​ $ 5,417 ​ — ​ $ — ​ 10,380 ​ $ 81 June 2, 2023 ​ June 15, 2023 ​ June 30, 2023 ​ ​ 0.25 ​ ​ 5,417 ​ — ​ ​ — ​ 9,045 ​ ​ 73 September 1, 2023 ​ September 15, 2023 ​ September 29, 2023 ​ ​ 0.25 ​ ​ 5,417 ​ — ​ ​ — ​ 16,514 ​ ​ 123 Total distributions declared ​ ​ ​ ​ $ 0.75 ​ $ 16,251 — ​ $ — 35,939 $ 277 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2022: March 2, 2022 ​ March 16, 2022 ​ March 31, 2022 ​ $ 0.25 ​ $ 5,417 — ​ $ — 25,229 ​ $ 276 June 1, 2022 ​ June 15, 2022 ​ June 30, 2022 ​ ​ 0.25 ​ ​ 5,416 ​ — ​ ​ — ​ 29,655 ​ ​ 280 September 1, 2022 ​ September 15, 2022 ​ September 30, 2022 ​ 0.25 ​ 5,416 — ​ — 20,789 ​ 164 Total distributions declared ​ ​ ​ ​ ​ $ 0.75 ​ $ 16,249 — ​ $ — 75,673 ​ $ 720 ​

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Summary of Significant Accounting Policies
Return of capital distributions	$ 0	$ 0	$ 0	$ 290
Investment, Type [Extensible Enumeration]	mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember	mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember	mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember	mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember
Unamortized discounts and loan origination fees	$ 4,149		$ 4,149		$ 4,701
Upfront loan origination and closing fees received	$ 202	$ 1,126	$ 1,003	$ 1,871

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Components of the Company's investment income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Summary of Significant Accounting Policies
Interest income	$ 12,804	$ 12,491	$ 37,553	$ 30,602
PIK interest income	2,430	1,240	7,193	4,458
Dividend income	1,017	1,051	3,169	3,108
Fee income	(836)	412	(356)	1,604
Prepayment gain (loss)	29	495	378	758
Accretion of discounts and amortization of premiums	199	227	857	872
Total investment income	15,643	15,916	48,794	41,402
PIK dividends	117	$ 124	359	$ 350
Reversal of previously accrued fee income, associated with IT Global Holding, LLC.			1,046
Fair value of the Company's investments on non-accrual status	$ 6,155		$ 6,155		$ 2,835

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2012 D	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) item	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) item
Summary of Significant Accounting Policies
Dividend reinvestment plan minimum time requirement to opt out dividend payment | D	3
Unamortized deferred financing costs		$ 3,566		$ 3,566		$ 4,486
Amortization of deferred financing costs		330	$ 522	977	$ 1,613
Deferred offering costs		262		$ 262		$ 184
Number of investments held in portfolio company that was denominated in Australian dollars | item						1
Number of investments with foreign denomination | item				0
Excise tax accrued (in percent)				4%
Net expense (benefit) for U.S. federal excise tax		95	55	$ 345	64
Payables for excise taxes		106		106		$ 1
U.S. federal and state corporate-level income taxes, Net tax expense		$ 0	$ 923	$ 150	$ 1,225

Investments - Composition of th

Investments - Composition of the Company's investment portfolio, at amortized cost and fair value (with corresponding percentage of total portfolio investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Investments
Amortized Cost	$ 536,795	$ 579,307
Fair Value	$ 518,284	$ 541,040
Amortized Cost, Percentage of total portfolio investments	100%	100%
Fair Value, Percentage of total portfolio investments	100%	100%
Senior Secured Loans
Investments
Amortized Cost	$ 419,994	$ 436,066
Fair Value	$ 416,316	$ 434,023
Amortized Cost, Percentage of total portfolio investments	78.20%	75.30%
Fair Value, Percentage of total portfolio investments	80.30%	80.20%
Unitranche Secured Loans
Investments
Amortized Cost	$ 13,522	$ 45,352
Fair Value	$ 13,548	$ 20,633
Amortized Cost, Percentage of total portfolio investments	2.50%	7.80%
Fair Value, Percentage of total portfolio investments	2.60%	3.80%
Junior Secured Loans
Investments
Amortized Cost	$ 29,215	$ 21,141
Fair Value	$ 27,425	$ 22,193
Amortized Cost, Percentage of total portfolio investments	5.40%	3.60%
Fair Value, Percentage of total portfolio investments	5.30%	4.10%
LLC equity interest in SLF
Investments
Amortized Cost	$ 42,650	$ 42,650
Fair Value	$ 33,269	$ 35,509
Amortized Cost, Percentage of total portfolio investments	8%	7.40%
Fair Value, Percentage of total portfolio investments	6.40%	6.60%
Equity Securities
Investments
Amortized Cost	$ 31,414	$ 34,098
Fair Value	$ 27,726	$ 28,682
Amortized Cost, Percentage of total portfolio investments	5.90%	5.90%
Fair Value, Percentage of total portfolio investments	5.40%	5.30%

Investments - Composition of _2

Investments - Composition of the Company's investment portfolio by geographic region, at amortized cost and fair value (with corresponding percentage of total portfolio investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Investments
Amortized Cost	$ 536,795	$ 579,307
Fair Value	$ 518,284	$ 541,040
Amortized Cost, Percentage of total portfolio investments	100%	100%
Fair Value, Percentage of total portfolio investments	100%	100%
International
Investments
Amortized Cost		$ 11,860
Fair Value		$ 10,405
Amortized Cost, Percentage of total portfolio investments	0%	2.10%
Fair Value, Percentage of total portfolio investments	0%	1.90%
Midwest
Investments
Amortized Cost	$ 163,145	$ 157,558
Fair Value	$ 141,810	$ 143,691
Amortized Cost, Percentage of total portfolio investments	30.40%	27.20%
Fair Value, Percentage of total portfolio investments	27.40%	26.60%
Northeast
Investments
Amortized Cost	$ 106,674	$ 100,961
Fair Value	$ 109,509	$ 104,157
Amortized Cost, Percentage of total portfolio investments	19.90%	17.40%
Fair Value, Percentage of total portfolio investments	21.10%	19.20%
Southeast
Investments
Amortized Cost	$ 158,568	$ 158,548
Fair Value	$ 154,441	$ 155,624
Amortized Cost, Percentage of total portfolio investments	29.50%	27.40%
Fair Value, Percentage of total portfolio investments	29.80%	28.80%
Southwest
Investments
Amortized Cost	$ 25,008	$ 27,348
Fair Value	$ 25,931	$ 28,287
Amortized Cost, Percentage of total portfolio investments	4.70%	4.70%
Fair Value, Percentage of total portfolio investments	5%	5.20%
West
Investments
Amortized Cost	$ 83,400	$ 123,032
Fair Value	$ 86,593	$ 98,876
Amortized Cost, Percentage of total portfolio investments	15.50%	21.20%
Fair Value, Percentage of total portfolio investments	16.70%	18.30%

Investments - Composition of _3

Investments - Composition of the Company's investment portfolio by industry, at amortized cost and fair value (with corresponding percentage of total portfolio investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Investments
Amortized Cost	$ 536,795	$ 579,307
Fair Value	$ 518,284	$ 541,040
Amortized Cost, Percentage of total portfolio investments	100%	100%
Fair Value, Percentage of total portfolio investments	100%	100%
Aerospace & Defense
Investments
Amortized Cost	$ 7,601	$ 7,461
Fair Value	$ 7,578	$ 7,436
Amortized Cost, Percentage of total portfolio investments	1.40%	1.30%
Fair Value, Percentage of total portfolio investments	1.40%	1.40%
Automotive
Investments
Amortized Cost	$ 17,781	$ 16,775
Fair Value	$ 16,626	$ 16,637
Amortized Cost, Percentage of total portfolio investments	3.30%	2.90%
Fair Value, Percentage of total portfolio investments	3.20%	3.10%
Banking
Investments
Amortized Cost	$ 17,031	$ 17,790
Fair Value	$ 16,436	$ 19,817
Amortized Cost, Percentage of total portfolio investments	3.20%	3.10%
Fair Value, Percentage of total portfolio investments	3.20%	3.70%
Beverage, Food & Tobacco
Investments
Amortized Cost	$ 9,924	$ 15,625
Fair Value	$ 11,434	$ 12,470
Amortized Cost, Percentage of total portfolio investments	1.90%	2.70%
Fair Value, Percentage of total portfolio investments	2.20%	2.30%
Capital Equipment
Investments
Amortized Cost	$ 18,442	$ 18,615
Fair Value	$ 18,936	$ 19,012
Amortized Cost, Percentage of total portfolio investments	3.40%	3.20%
Fair Value, Percentage of total portfolio investments	3.60%	3.50%
Chemicals, Plastics & Rubber
Investments
Amortized Cost	$ 2,917	$ 2,924
Fair Value	$ 3,996	$ 4,445
Amortized Cost, Percentage of total portfolio investments	0.50%	0.50%
Fair Value, Percentage of total portfolio investments	0.80%	0.80%
Construction & Building
Investments
Amortized Cost	$ 8,698	$ 6,642
Fair Value	$ 8,800	$ 6,706
Amortized Cost, Percentage of total portfolio investments	1.60%	1.10%
Fair Value, Percentage of total portfolio investments	1.70%	1.20%
Consumer Goods: Durable
Investments
Amortized Cost	$ 8,792	$ 9,333
Fair Value	$ 8,739	$ 9,338
Amortized Cost, Percentage of total portfolio investments	1.60%	1.60%
Fair Value, Percentage of total portfolio investments	1.70%	1.70%
Consumer Goods: Non-Durable
Investments
Amortized Cost	$ 3,415	$ 28,276
Fair Value	$ 3,023	$ 3,508
Amortized Cost, Percentage of total portfolio investments	0.60%	4.90%
Fair Value, Percentage of total portfolio investments	0.60%	0.60%
Environmental Industries
Investments
Amortized Cost	$ 5,434	$ 6,164
Fair Value	$ 5,895	$ 6,558
Amortized Cost, Percentage of total portfolio investments	1%	1.10%
Fair Value, Percentage of total portfolio investments	1.10%	1.20%
FIRE: Finance
Investments
Amortized Cost	$ 14,585	$ 25,021
Fair Value	$ 15,037	$ 23,892
Amortized Cost, Percentage of total portfolio investments	2.70%	4.30%
Fair Value, Percentage of total portfolio investments	2.90%	4.40%
FIRE: Real Estate
Investments
Amortized Cost	$ 86,633	$ 81,922
Fair Value	$ 85,387	$ 82,498
Amortized Cost, Percentage of total portfolio investments	16.10%	14.10%
Fair Value, Percentage of total portfolio investments	16.50%	15.20%
Healthcare & Pharmaceuticals
Investments
Amortized Cost	$ 67,025	$ 59,659
Fair Value	$ 66,309	$ 59,273
Amortized Cost, Percentage of total portfolio investments	12.50%	10.30%
Fair Value, Percentage of total portfolio investments	12.80%	11%
High Tech Industries
Investments
Amortized Cost	$ 41,358	$ 52,385
Fair Value	$ 40,164	$ 52,891
Amortized Cost, Percentage of total portfolio investments	7.70%	9%
Fair Value, Percentage of total portfolio investments	7.70%	9.80%
Hotels, Gaming & Leisure
Investments
Amortized Cost	$ 111	$ 2,702
Fair Value	$ 115	$ 2,720
Amortized Cost, Percentage of total portfolio investments	0%	0.50%
Fair Value, Percentage of total portfolio investments	0%	0.50%
Investment Funds & Vehicles
Investments
Amortized Cost	$ 42,650	$ 42,650
Fair Value	$ 33,269	$ 35,509
Amortized Cost, Percentage of total portfolio investments	8%	7.40%
Fair Value, Percentage of total portfolio investments	6.40%	6.60%
Media: Advertising, Printing & Publishing
Investments
Amortized Cost	$ 18,241	$ 17,470
Fair Value	$ 20,497	$ 19,777
Amortized Cost, Percentage of total portfolio investments	3.40%	3%
Fair Value, Percentage of total portfolio investments	4%	3.70%
Media: Broadcasting & Subscription
Investments
Amortized Cost	$ 3,984	$ 2,747
Fair Value	$ 2,763	$ 2,691
Amortized Cost, Percentage of total portfolio investments	0.70%	0.50%
Fair Value, Percentage of total portfolio investments	0.50%	0.50%
Media: Diversified & Production
Investments
Amortized Cost	$ 41,260	$ 36,018
Fair Value	$ 41,435	$ 36,164
Amortized Cost, Percentage of total portfolio investments	7.70%	6.20%
Fair Value, Percentage of total portfolio investments	8%	6.70%
Retail
Investments
Amortized Cost	$ 2,422	$ 9,247
Fair Value	$ 1,985	$ 9,306
Amortized Cost, Percentage of total portfolio investments	0.50%	1.60%
Fair Value, Percentage of total portfolio investments	0.40%	1.70%
Services: Business
Investments
Amortized Cost	$ 56,224	$ 56,249
Fair Value	$ 57,316	$ 57,308
Amortized Cost, Percentage of total portfolio investments	10.50%	9.70%
Fair Value, Percentage of total portfolio investments	11.10%	10.60%
Services: Consumer
Investments
Amortized Cost	$ 39,028	$ 40,086
Fair Value	$ 30,398	$ 31,324
Amortized Cost, Percentage of total portfolio investments	7.30%	6.90%
Fair Value, Percentage of total portfolio investments	5.90%	5.80%
Telecommunications
Investments
Amortized Cost	$ 7,246	$ 7,502
Fair Value	$ 7,356	$ 7,595
Amortized Cost, Percentage of total portfolio investments	1.40%	1.30%
Fair Value, Percentage of total portfolio investments	1.40%	1.40%
Wholesale
Investments
Amortized Cost	$ 15,993	$ 16,044
Fair Value	$ 14,790	$ 14,165
Amortized Cost, Percentage of total portfolio investments	3%	2.80%
Fair Value, Percentage of total portfolio investments	2.90%	2.60%

Investments - MRCC Senior Loan

Investments - MRCC Senior Loan Fund I, LLC (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) item	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) item	Jun. 09, 2023 USD ($)
Investments
Number of representatives | item			1
Outstanding commitments to fund investments under undrawn revolvers and delayed draw commitments	$ 41,899		$ 41,899		$ 63,450
LSW
Investments
Number of representatives | item			1
SLF
Investments
Percentage of equity interest	50%		50%		50%
Equity commitments	$ 50,000		$ 50,000		$ 50,000
Funded amount	42,650		42,650		42,650
Dividend income		$ 900		$ 2,700
Senior secured loans	$ 166,639		$ 166,639		$ 197,867
Weighted average interest rate	9.70%		9.70%		9.70%
Number of portfolio company investments in SLF | item			53		60
Largest portfolio company investment	$ 6,597		$ 6,597		$ 6,650
Total of five largest portfolio company investments	26,900		26,900		27,026
SLF
Investments
Equity commitments	100,000		100,000		100,000
Funded amount	85,300		85,300
Allocable expenses	45	$ 65	154	$ 175
Total assets at fair value	158,667		$ 158,667		$ 192,830
Number of portfolio company investments on non-accrual status | item			4		1
Investments on non-accrual status with a fair value	5,397		$ 5,397		$ 415
Outstanding commitments to fund investments under undrawn revolvers and delayed draw commitments	3,720		3,720		$ 4,579
SLF | SLF Credit Facility
Investments
Maximum borrowing capacity	$ 110,000		$ 110,000			$ 175,000
SLF | SLF Credit Facility | LIBOR
Investments
Interest rate, basis spread			2.10%

Investments - Schedule of Inves

Investments - Schedule of Investments (Details) - USD ($) $ in Thousands	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2022	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Investments
Investment, Type [Extensible Enumeration]		mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember		mrcc:InvestmentInEquityOfMrccSeniorLoanFundILlcMember
Fair Value		$ 518,284	$ 541,040
Investment, Identifier [Axis]: 360 Holdco, Inc. ( Delayed Draw), Senior Secured Loans, due 8/2/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: 360 Holdco, Inc., Senior Secured Loans, due 8/2/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A P C O Worldwide, Inc, Equity Securities, Class A voting common stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:APCOWorldwideIncMember	mrcc:APCOWorldwideIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Nov. 01, 2017	Nov. 01, 2017
Fair Value		$ 1,098	$ 921
Investment, Non-income Producing [true false]		true	true
Number of shares held		100
Investment, Identifier [Axis]: A Q Carver Buyer, Inc., Senior Secured Loans, due 9/23/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A S G I I, L L C ( Delayed Draw), Unitranche Secured Loans, 5/25/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ASGIILLCMember	mrcc:ASGIILLCMember
Investment, Type [Extensible Enumeration]		Unitranche Debt [Member]	Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.40%	6.25%
Interest Rate		11.77%	10.67%
Acquisition Date		May 25, 2022	May 25, 2022
Maturity		May 25, 2028	May 25, 2028
Principal		$ 285	$ 285
Fair Value		$ 140	$ 51
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: A S G I I, L L C, Unitranche Secured Loans, due 5/25/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ASGIILLCMember	mrcc:ASGIILLCMember
Investment, Type [Extensible Enumeration]		Unitranche Debt [Member]	Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.40%	6.25%
Interest Rate		11.77%	10.67%
Acquisition Date		May 25, 2022	May 25, 2022
Maturity		May 25, 2028	May 25, 2028
Principal		$ 1,900	$ 1,900
Fair Value		$ 1,900	$ 1,900
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Delayed Draw), Senior Secured Loans, due 12/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Revolver), Senior Secured Loans, due 12/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C, Senior Secured Loans, due 12/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Ad Theorent Holding Company, Inc. Equity Securities, common stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AdTheorentHoldingCompanyIncMember	mrcc:AdTheorentHoldingCompanyIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 22, 2016	Dec. 22, 2016
Fair Value		$ 229	$ 294
Investment, Non-income Producing [true false]		true	true
Number of shares held		177,362	177,362
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 12/21/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcDelayedDrawMember	mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		9.26%	10.26%
Interest Rate, Paid in Cash			13.77%
Interest Rate, Paid in Kind		14.65%	1%
Acquisition Date		Dec. 21, 2022	Dec. 21, 2022
Maturity		Dec. 21, 2027	Dec. 21, 2027
Principal		$ 667	$ 667
Fair Value		$ 293
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 3/16/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.10%
Interest Rate, Paid in Kind		13.42%
Acquisition Date		Aug. 29, 2023
Maturity		Mar. 16, 2027
Principal		$ 155
Fair Value		$ 107
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Amelia Holding II, LLC (Revolver), Due 12/21/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcRevolverMember	mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		10.26%	10.26%
Interest Rate, Paid in Cash		14.65%	13.77%
Interest Rate, Paid in Kind		1%	1%
Acquisition Date		Dec. 21, 2022	Dec. 21, 2022
Maturity		Dec. 21, 2027	Dec. 21, 2027
Principal		$ 133	$ 133
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Amelia Holding II, LLC, Due 12/21/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcMember	mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		10.26%	10.26%
Interest Rate, Paid in Cash		14.65%	13.77%
Interest Rate, Paid in Kind		1%	1%
Acquisition Date		Dec. 21, 2022	Dec. 21, 2022
Maturity		Dec. 21, 2027	Dec. 21, 2027
Principal		$ 2,016	$ 2,000
Fair Value		$ 2,016	$ 1,940
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Dec. 21, 2022
Maturity		Dec. 21, 2032
Fair Value		$ 28
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities, Warrant
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmeliaHoldingIiLlcMember
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Dec. 21, 2022
Maturity			Dec. 21, 2032
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Delayed Draw), Senior Secured Loans, due 6/10/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember	mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		12%	12%
Interest Rate, Paid in Cash		18.50%	17.50%
Interest Rate, Paid in Kind		2%	2%
Acquisition Date		Jun. 10, 2022	Jun. 10, 2022
Maturity		Jun. 10, 2025	Jun. 10, 2025
Principal		$ 1,377	$ 1,689
Fair Value		$ 1,293	$ 1,539
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Revolver), Senior Secured Loans, due 6/10/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember	mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		12%	12%
Interest Rate, Paid in Cash		18.50%	17.50%
Interest Rate, Paid in Kind		2%	2%
Acquisition Date		Jun. 10, 2022	Jun. 10, 2022
Maturity		Jun. 10, 2025	Jun. 10, 2025
Principal		$ 500	$ 500
Fair Value		$ 123	$ 118
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C, Equity Securities, Warrants
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember	mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 10, 2022	Jun. 10, 2022
Maturity		Jun. 10, 2032	Jun. 10, 2032
Fair Value		$ 56	$ 69
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: American Community Homes, Inc. ( Revolver), Senior Secured Loans Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.11%	8.11%
Interest Rate, Paid in Kind		13.43%	12.44%
Acquisition Date		Mar. 30, 2020	Mar. 30, 2020
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 2,500	$ 2,500
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities Due 12/18/2024, Warrants
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value					$ 264
Number of shares held		4,940
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities, Common Stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 29, 2022	Dec. 29, 2022
Principal		$ 0
Investment, Non-income Producing [true false]		true	false
Number of shares held			4,940
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Acquisition Date 3/29/2019
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 3,381	$ 3,694	$ 3,728	4,357
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.11%	8.11%
Interest Rate, Paid in Kind		13.43%	12.44%
Acquisition Date		Mar. 29, 2019	Mar. 29, 2019
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 5,121	$ 4,640
Fair Value		$ 3,381	$ 3,694
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Acquisition Date 8/10/2018
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 1,826	$ 1,996	2,014	3,164
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.11%	8.11%
Interest Rate, Paid in Kind		13.43%	12.44%
Acquisition Date		Aug. 10, 2018	Aug. 10, 2018
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 2,766	$ 2,507
Fair Value		$ 1,826	$ 1,996
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Acquisition Date 7/22/2014
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 8,193	$ 8,953	9,034	10,457
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.11%	8.11%
Interest Rate			12.44%
Interest Rate, Paid in Kind		13.43%
Acquisition Date		Jul. 22, 2014	Jul. 22, 2014
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 12,411	$ 11,246
Fair Value		$ 8,193	$ 8,953
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Acquisition Date 12/30/2019
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]
Fair Value		$ 77	$ 85	85	99
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.11%	8.11%
Interest Rate, Paid in Kind		13.43%	12.44%
Acquisition Date		Dec. 30, 2019	Dec. 30, 2019
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 117	$ 106
Fair Value		$ 77	$ 85
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Acquisition Date 9/30/2019
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 16	$ 17	18	20
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.11%	8.11%
Interest Rate, Paid in Kind		13.43%	12.44%
Acquisition Date		Sep. 30, 2019	Sep. 30, 2019
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 24	$ 22
Fair Value		$ 16	$ 17
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Acquisition Date 5/24/2017
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 497	$ 543	548	634
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.11%	8.11%
Interest Rate, Paid in Kind		13.43%	12.44%
Acquisition Date		May 24, 2017	May 24, 2017
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 752	$ 682
Fair Value		$ 497	$ 543
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Acquisition Date 7/22/2014
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Fair Value		$ 4,030	$ 4,258	4,249	4,753
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Due 12/31/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		12.61%	14.61%
Interest Rate, Paid in Kind		17.93%	18.94%
Acquisition Date		Jul. 22, 2014	Jul. 22, 2014
Maturity		Dec. 31, 2026	Dec. 31, 2026
Principal		$ 6,105	$ 5,348
Fair Value		$ 4,030	$ 4,258
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Aras Corporation ( Revolver), Senior Secured Loans, due 4/13/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArasCorporationMember	mrcc:ArasCorporationMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.50%	6.50%
Interest Rate		14%
Interest Rate, Paid in Cash			9.50%
Acquisition Date		Apr. 13, 2021	Apr. 13, 2021
Maturity		Apr. 13, 2027	Apr. 13, 2027
Principal		$ 150	$ 150
Fair Value		$ 110	$ 50
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Aras Corporation, Senior Secured Loans, due 4/13/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArasCorporationMember	mrcc:ArasCorporationMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.90%	7%
Interest Rate, Paid in Cash		8.95%	7.16%
Interest Rate, Paid in Kind		3.25%	3.75%
Acquisition Date		Apr. 13, 2021	Apr. 13, 2021
Maturity		Apr. 13, 2027	Apr. 13, 2027
Principal		$ 2,214	$ 2,155
Fair Value		$ 2,231	$ 2,167
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, One, due 3/16/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.85%
Interest Rate, Paid in Kind		13.17%
Acquisition Date		Mar. 16, 2021
Maturity		Mar. 16, 2027
Principal		$ 4,572
Fair Value		$ 2,419
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, Two, due 3/16/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.10%
Interest Rate		13.42%
Acquisition Date		Jul. 14, 2023
Maturity		Mar. 16, 2027
Principal		$ 155
Fair Value		$ 155
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Arcstor Midco, LLC, Due 3/16/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ArcstorMidcoLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.60%
Interest Rate, Paid in Cash			8.17%
Interest Rate, Paid in Kind			3.75%
Acquisition Date			Mar. 16, 2021
Maturity			Mar. 16, 2027
Principal			$ 4,528
Fair Value			$ 4,122
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Ascent Midco, L L C ( Revolver), Senior Secured Loans Due 2/5/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.75%
Interest Rate			10.14%
Acquisition Date			Feb. 05, 2020
Maturity			Feb. 05, 2025
Principal			$ 1,129
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Ascent Midco, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread			0%
Interest Rate, Paid in Kind		8%	8%
Acquisition Date		Feb. 05, 2020	Feb. 05, 2020
Principal		$ 0
Fair Value		$ 1,914	$ 1,969	$ 1,418	2,554
Investment, Non-income Producing [true false]		false	false
Number of shares held				2,032,258
Investment, Identifier [Axis]: Ascent Midco, L L C, Senior Secured Loans Due 2/5/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.75%
Interest Rate			10.14%
Acquisition Date			Feb. 05, 2020
Maturity			Feb. 05, 2025
Principal			$ 6,217
Fair Value			$ 6,217	$ 6,160	6,392
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jan. 04, 2019	Jan. 04, 2019
Fair Value		$ 418	$ 522
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Five, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.25%
Interest Rate		11.93%	11.39%
Acquisition Date		Dec. 22, 2022	Dec. 22, 2022
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 399	$ 400
Fair Value		$ 394	$ 399
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Four, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Aug. 04, 2022	Aug. 04, 2022
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 790	$ 796
Fair Value		$ 779	$ 794
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, One, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jan. 04, 2019	Jan. 04, 2019
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 1,905	$ 1,920
Fair Value		$ 1,878	$ 1,915
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Three, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jul. 01, 2021	Jul. 01, 2021
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 274	$ 276
Fair Value		$ 270	$ 275
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Two, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jun. 25, 2020	Jun. 25, 2020
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 464	$ 468
Fair Value		$ 458	$ 467
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Attom Intermediate Holdco, LLC (Revolver), Senior Secured Loans, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember	mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.25%
Interest Rate		11.93%	10.69%
Acquisition Date		Jan. 04, 2019	Jan. 04, 2019
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 320	$ 320
Fair Value		$ 118
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Avalara, Inc. (Revolver), Senior Secured Loans, due 10/19/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AvalaraInc.Member	mrcc:AvalaraInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember	mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.25%	7.25%
Interest Rate		12.64%	11.83%
Acquisition Date		Oct. 19, 2022	Oct. 19, 2022
Maturity		Oct. 19, 2028	Oct. 19, 2028
Principal		$ 400	$ 400
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Avalara, Inc. Senior Secured Loans, due 10/19/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AvalaraInc.Member	mrcc:AvalaraInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember	mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.25%	7.25%
Interest Rate		12.64%	11.83%
Acquisition Date		Oct. 19, 2022	Oct. 19, 2022
Maturity		Oct. 19, 2028	Oct. 19, 2028
Principal		$ 4,000	$ 4,000
Fair Value		$ 4,040	$ 3,900
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Avison Young ( U S A) Inc., Senior Secured Loans, due 1/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BLSTOperatingCompanyLLCMember	mrcc:BLSTOperatingCompanyLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Retail	Retail
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 28, 2020	Aug. 28, 2020
Fair Value		$ 420	$ 420
Investment, Non-income Producing [true false]		true	true
Number of shares held		139,883
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Senior Secured Loans, due 8/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BLSTOperatingCompanyLLCMember	mrcc:BLSTOperatingCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Retail
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		9.50%	8.50%
Interest Rate			12.62%
Interest Rate, Paid in Cash		5.44%
Interest Rate, Paid in Kind		12.94%
Acquisition Date		Aug. 28, 2020	Aug. 28, 2020
Maturity		Aug. 28, 2025	Aug. 28, 2025
Principal		$ 639	$ 588
Fair Value		$ 600	$ 571
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Bluesight, Inc (Revolver) Senior Secured Loans 7/17/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.25%
Interest Rate		12.57%
Acquisition Date		Jul. 17, 2023
Maturity		Jul. 17, 2029
Principal		$ 174
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bluesight, Inc Senior Secured Loans, 7/17/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.25%
Interest Rate		12.57%
Acquisition Date		Jul. 17, 2023
Maturity		Jul. 17, 2029
Principal		$ 2,000
Fair Value		$ 1,940
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Class B Common Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jul. 17, 2023
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Preferred units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BluesightIncMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate, Paid in Kind		9%
Acquisition Date		Jul. 17, 2023
Fair Value		$ 21
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Delayed Draw) , Senior Secured Loans, due 9/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.25%
Interest Rate			10.98%
Acquisition Date			Sep. 08, 2021
Maturity			Sep. 08, 2027
Principal			$ 1,906
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Revolver), Senior Secured Loans, due 9/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.25%
Interest Rate			10.98%
Acquisition Date			Sep. 08, 2021
Maturity			Sep. 08, 2027
Principal			$ 1,069
Fair Value			$ 389
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings), Senior Secured Loans, due 9/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.25%
Interest Rate			10.98%
Acquisition Date			Sep. 08, 2021
Maturity			Sep. 08, 2027
Principal			$ 13,195
Fair Value			$ 12,898
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Bonterra, LLC (Revolver), Senior Secured Loans, Due 9/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.25%
Interest Rate		12.64%
Acquisition Date		Sep. 08, 2021
Maturity		Sep. 08, 2027
Principal		$ 1,069
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, One, Due 9/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.25%
Interest Rate		12.64%
Acquisition Date		Sep. 08, 2021
Maturity		Sep. 08, 2027
Principal		$ 13,437
Fair Value		$ 13,135
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, Two, Due 9/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8%
Interest Rate, Paid in Kind		13.39%
Acquisition Date		Sep. 28, 2023
Maturity		Sep. 08, 2027
Principal		$ 1,902
Fair Value		$ 1,902
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Born To Run, L L C ( Delayed Draw) Senior Secured Loans, due 4/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			10.73%
Acquisition Date			Apr. 01, 2021
Maturity			Apr. 01, 2027
Principal			$ 470
Fair Value			$ 452
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Born To Run, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BornToRunLLCMember	mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Apr. 01, 2021	Apr. 01, 2021
Fair Value			$ 233
Investment, Non-income Producing [true false]		false	true
Number of shares held		269,438
Investment, Identifier [Axis]: Born To Run, L L C, Senior Secured Loans, due 4/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BornToRunLLCMember	mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.26%	6%
Interest Rate		11.63%	10.73%
Acquisition Date		Apr. 01, 2021	Apr. 01, 2021
Maturity		Apr. 01, 2027	Apr. 01, 2027
Principal		$ 3,430	$ 3,448
Fair Value		$ 2,662	$ 3,318
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Born To Run, LLC, Senior Secured Loans, Two, Due 4/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BornToRunLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.26%
Interest Rate		11.63%
Acquisition Date		Apr. 01, 2021
Maturity		Apr. 01, 2027
Principal		$ 467
Fair Value		$ 363
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Brickell Bay Acquisition Corp, Senior Secured Loans, due 2/12/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BrickellBayAcquisitionCorpMember	mrcc:BrickellBayAcquisitionCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.65%	6.50%
Interest Rate		11.90%	10.24%
Acquisition Date		Feb. 12, 2021	Feb. 12, 2021
Maturity		Feb. 12, 2026	Feb. 12, 2026
Principal		$ 1,866	$ 1,880
Fair Value		$ 1,866	$ 1,847
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, One, due 11/5/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, Two, due 11/5/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Burroughs, Inc. ( Revolver), Senior Secured Loans, due 12/22/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.72%
Acquisition Date			Dec. 22, 2017
Maturity			Dec. 22, 2023
Principal			$ 1,215
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Burroughs, Inc. (Revolver), Senior Secured Loans, due 12/22/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.60%
Interest Rate		11.93%
Acquisition Date		Dec. 22, 2017
Maturity		Dec. 20, 2024
Principal		$ 1,215
Fair Value		$ 1,020
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, One, due 12/22/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.60%
Interest Rate		11.93%
Acquisition Date		Dec. 22, 2017
Maturity		Dec. 20, 2024
Principal		$ 4,976
Fair Value		$ 4,976
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, due 12/22/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BurroughsInc.Member
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate, Paid in Kind			10.72%
Acquisition Date			Dec. 22, 2017
Maturity			Dec. 22, 2023
Principal			$ 5,201
Fair Value			$ 5,201
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, One, due 4/10/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, Two, due 4/10/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC) (Revolver), Senior Secured Loans
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Fair Value					550
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Equity Securities, Common Stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Number of shares held		58,779		58,779
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, One
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, Two
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Senior Secured Loans
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			May 02, 2017
Fair Value			$ 146	$ 146	4,561
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, One, due 12/17/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CgiAutomatedManufacturingLlcMember	mrcc:CgiAutomatedManufacturingLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.11%	6.50%
Interest Rate		12.43%	11.34%
Acquisition Date		Sep. 09, 2022	Sep. 09, 2022
Maturity		Dec. 17, 2026	Dec. 17, 2026
Principal		$ 3,900	$ 3,975
Fair Value		$ 3,846	$ 3,975
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, Two, due 12/17/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:CgiAutomatedManufacturingLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.11%	6.50%
Interest Rate		12.43%	11.34%
Acquisition Date		Sep. 30, 2022	Sep. 30, 2022
Maturity		Dec. 17, 2026	Dec. 17, 2026
Principal		$ 1,119	$ 1,141
Fair Value		$ 1,104	$ 1,141
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Cadent, L L C ( Revolver), Senior Secured Loans, due 9/11/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Cadent, L L C, Senior Secured Loans, due 9/11/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Calabrio, Inc. ( Revolver), Senior Secured Loans, due 4/16/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CalabrioIncMember	mrcc:CalabrioIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.13%	7%
Interest Rate		12.45%	11.75%
Acquisition Date		Apr. 16, 2021	Apr. 16, 2021
Maturity		Apr. 16, 2027	Apr. 16, 2027
Principal		$ 409	$ 409
Fair Value		$ 234	$ 233
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Calabrio, Inc., Senior Secured Loans, due 4/16/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CalabrioIncMember	mrcc:CalabrioIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.13%	7%
Interest Rate		12.44%	11.73%
Acquisition Date		Apr. 16, 2021	Apr. 16, 2021
Maturity		Apr. 16, 2027	Apr. 16, 2027
Principal		$ 3,400	$ 3,400
Fair Value		$ 3,400	$ 3,379
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: California Pizza Kitchen, Inc., Equity Securities, Common units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CaliforniaPizzaKitchenInc.Member
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Beverage, Food & Tobacco
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Aug. 19, 2016
Fair Value			$ 1,266
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: Cano Health, L L C, Senior Secured Loans, due 11/23/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Caravel Autism Health LLC One Senior Secured Loans due 6/30/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		5.76%
Interest Rate		11.01%
Acquisition Date		Jun. 30, 2021
Maturity		Jun. 30, 2027
Principal		$ 1,396
Fair Value		$ 1,368
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Delayed Draw), Senior Secured Loans, due 6/30/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			8.75%
Interest Rate, Paid in Cash			8.97%
Interest Rate, Paid in Kind			3%
Acquisition Date			Jun. 30, 2021
Maturity			Jun. 30, 2027
Principal			$ 3,750
Fair Value			$ 173
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Revolver), Senior Secured Loans, due 6/30/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CaravelAutismHealthLLCMember	mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.76%	8.75%
Interest Rate		11.01%
Interest Rate, Paid in Kind			3%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2027	Jun. 30, 2027
Principal		$ 1,269	$ 1,260
Fair Value		$ 484	$ 1,048
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Caravel Autism Health, L L C, Senior Secured Loans, due 6/30/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CaravelAutismHealthLLCMember	mrcc:CaravelAutismHealthLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.76%	8.75%
Interest Rate		11.01%
Interest Rate, Paid in Cash			8.97%
Interest Rate, Paid in Kind			3%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2027	Jun. 30, 2027
Principal		$ 5,024	$ 5,016
Fair Value		$ 4,923	$ 4,630
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Cassavant Holdings, L L C, Unitranche Secured Loans, due 9/8/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CassavantHoldingsLLCMember	mrcc:CassavantHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Unitranche Debt [Member]	Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]		Aerospace & Defense	Aerospace & Defense
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.36%	6.50%
Interest Rate		13.69%	10.62%
Acquisition Date		Sep. 08, 2021	Sep. 08, 2021
Maturity		Sep. 08, 2026	Sep. 08, 2026
Principal		$ 7,697	$ 7,580
Fair Value		$ 7,578	$ 7,436
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Delayed Draw), Senior Secured Loans, due 4/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember	mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE Real Estate Sector [Member]	FIRE Real Estate Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.25%	8.25%
Interest Rate		13.58%	12.43%
Acquisition Date		May 03, 2022	May 03, 2022
Maturity		Apr. 30, 2025	Apr. 30, 2025
Principal		$ 285	$ 337
Fair Value		$ 286	$ 337
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Revolver), Senior Secured Loans, due 4/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember	mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE Real Estate Sector [Member]	FIRE Real Estate Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.25%	8.25%
Interest Rate		13.57%	12.43%
Acquisition Date		May 03, 2022	May 03, 2022
Maturity		Apr. 30, 2025	Apr. 30, 2025
Principal		$ 1,395	$ 1,653
Fair Value		$ 870	$ 719
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C, Senior Secured Loans, due 4/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember	mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE Real Estate Sector [Member]	FIRE Real Estate Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.25%	8.25%
Interest Rate		13.58%	12.43%
Acquisition Date		May 03, 2022	May 03, 2022
Maturity		Apr. 30, 2025	Apr. 30, 2025
Principal		$ 2,784	$ 3,300
Fair Value		$ 2,798	$ 3,296
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Chess.com, L L C ( Revolver), Senior Secured Loans, due 12/31/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Chess.comLLCMember	mrcc:Chess.comLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		11.99%	11.23%
Acquisition Date		Dec. 31, 2021	Dec. 31, 2021
Maturity		Dec. 31, 2027	Dec. 31, 2027
Principal		$ 652	$ 652
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Chess.com, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Chess.comLLCMember	mrcc:Chess.comLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 31, 2021	Dec. 31, 2021
Fair Value		$ 55	$ 50
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Chess.com, L L C, Senior Secured Loans, due 12/31/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Chess.comLLCMember	mrcc:Chess.comLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		11.99%	11.23%
Acquisition Date		Dec. 31, 2021	Dec. 31, 2021
Maturity		Dec. 31, 2027	Dec. 31, 2027
Principal		$ 5,910	$ 5,955
Fair Value		$ 5,866	$ 5,866
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Corel Inc., Senior Secured Loans, due 7/2/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Crownpeak Technology Inc. (Revolver) Senior Secured Loans, Due 2/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.35%	7.25%
Interest Rate		12.67%	11.47%
Acquisition Date		Feb. 28, 2019	Feb. 28, 2019
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 500	$ 500
Fair Value		$ 67
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Four, Due 2/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.25%	7.25%
Interest Rate		12.68%	11.41%
Acquisition Date		Sep. 27, 2022	Sep. 27, 2022
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 3,333	$ 3,333
Fair Value		$ 3,333	$ 3,333
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans One, Due 2/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.25%	7.25%
Interest Rate		12.68%	11.47%
Acquisition Date		Feb. 28, 2019	Feb. 28, 2019
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 4,000	$ 4,000
Fair Value		$ 4,000	$ 4,000
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Three, Due 2/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.25%	7.25%
Interest Rate		12.68%	11.47%
Acquisition Date		Feb. 28, 2019	Feb. 28, 2019
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 60	$ 60
Fair Value		$ 60	$ 60
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Two, Due 2/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CrownpeakTechnologyIncMember	mrcc:CrownpeakTechnologyIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.25%	7.25%
Interest Rate		12.37%	11.47%
Acquisition Date		Sep. 27, 2022	Sep. 27, 2022
Maturity		Feb. 28, 2025	Feb. 28, 2025
Principal		$ 1,273	$ 1,273
Fair Value		$ 1,273	$ 1,273
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Curion Holdings, L L C, Equity Securities, Common stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Curion Holdings, L L C [ Member]
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Aug. 17, 2018
Investment, Non-income Producing [true false]			true
Number of shares held			58,779
Investment, Identifier [Axis]: D S Parent, Inc., Senior Secured Loans, due 12/8/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Destination Media, Inc. ( Revolver), Senior Secured Loans, due 4/7/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.50%
Interest Rate			9.94%
Acquisition Date			Apr. 07, 2017
Maturity			Apr. 07, 2023
Principal			$ 542
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Destination Media, Inc. (Delayed Draw), Senior Secured Loans, due 6/21/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread		7.15%
Interest Rate		12.56%
Acquisition Date		Jun. 21, 2023
Maturity		Jun. 21, 2028
Principal		$ 500
Fair Value		$ 29
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Destination Media, Inc. (Revolver), Senior Secured Loans, due 6/21/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.15%
Interest Rate		12.56%
Acquisition Date		Jun. 21, 2023
Maturity		Jun. 21, 2028
Principal		$ 103
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 4/7/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.50%
Interest Rate			9.94%
Acquisition Date			Apr. 07, 2017
Maturity			Apr. 07, 2023
Principal			$ 377
Fair Value			$ 377
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 6/21/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DestinationMediaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.25%
Interest Rate		12.54%
Acquisition Date		Jun. 21, 2023
Maturity		Jun. 21, 2028
Principal		$ 998
Fair Value		$ 1,001
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, One, Class A-1 units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionIncMember	mrcc:DoradoAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Fair Value		$ 209	$ 215
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, Two, Class A-2 units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionIncMember	mrcc:DoradoAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Fair Value		$ 207	$ 224
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Delayed Draw) , Senior Secured Loans, due 6/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.72%
Acquisition Date			Jun. 30, 2021
Maturity			Jun. 30, 2026
Principal			$ 216
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Revolver) , Senior Secured Loans, due 6/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionInc.Member	mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		11.93%	10.92%
Interest Rate, Paid in Cash			8.08%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2026	Jun. 30, 2026
Principal		$ 596	$ 596
Fair Value			$ 596
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, One, due 6/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionInc.Member	mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		11.93%	10.72%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 30, 2026	Jun. 30, 2026
Principal		$ 4,900	$ 4,938
Fair Value		$ 4,778	$ 4,928
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, Two, Due 6/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DoradoAcquisitionInc.Member	mrcc:DoradoAcquisitionInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.65%	6.76%
Interest Rate		11.90%	11.34%
Acquisition Date		Nov. 27, 2022	Nov. 27, 2022
Maturity		Jun. 30, 2026	Jun. 30, 2026
Principal		$ 4,061	$ 4,082
Fair Value		$ 3,960	$ 4,074
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Delayed Draw), Senior Secured Loans, due 9/1/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.39%
Interest Rate, Paid in Kind			11.56%
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Maturity		Sep. 01, 2028	Sep. 01, 2028
Principal		$ 874	$ 330
Fair Value		$ 389	$ 102
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Revolver), Senior Secured Loans, due 9/1/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.39%	11.56%
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Maturity		Sep. 01, 2028	Sep. 01, 2028
Principal		$ 522	$ 522
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Equity Securities, Class A Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Fair Value		$ 132	$ 126
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Senior Secured Loans, due 9/1/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrawbridgePartnersLlcMember	mrcc:DrawbridgePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.39%
Interest Rate, Paid in Kind			11.56%
Acquisition Date		Sep. 01, 2022	Sep. 01, 2022
Maturity		Sep. 01, 2028	Sep. 01, 2028
Principal		$ 3,000	$ 3,000
Fair Value		$ 2,978	$ 2,971
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, One, due 10/1/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, Two, due 10/1/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Drilling Info Holdings, Inc., Senior Secured Loans, due 7/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Education Corporation of America, Equity Securities, Series G Preferred Stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EducationCorporationofAmericaMember	mrcc:EducationCorporationofAmericaMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		12%	12%
Acquisition Date		Sep. 03, 2015	Sep. 03, 2015
Investment, Non-income Producing [true false]		false	false
Number of shares held		8,333	8,333
Investment, Identifier [Axis]: Education Corporation of America, Junior Secured Loans
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EducationCorporationofAmericaMember	mrcc:EducationCorporationofAmericaMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]	Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		11%	11%
Interest Rate, Paid in Cash		14%	10.23%
Interest Rate, Paid in Kind		5.50%	5.50%
Acquisition Date		Sep. 03, 2015	Sep. 03, 2015
Principal		$ 833	$ 833
Fair Value		$ 2,085	$ 1,882
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Elevate Textiles, Inc. (fka International Textile Group, Inc.), Senior Secured Loans, due 9/30/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C ( Delayed Draw), Senior Secured Loans, due 4/14/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C, Senior Secured Loans, due 4/14/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc. ( Revolver), Senior Secured Loans, due 3/7/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, One, due 3/7/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, Two,due 3/7/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Equine Network, L L C, (Delayed Draw), Senior Secured Loans, due 12/31/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			10.24%
Acquisition Date			Dec. 31, 2020
Maturity			Dec. 31, 2025
Principal			$ 427
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Equine Network, L L C, (Revolver), Senior Secured Loans, due 12/31/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			10.30%
Acquisition Date			Dec. 31, 2020
Maturity			Dec. 31, 2025
Principal			$ 171
Fair Value			$ 127
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Equine Network, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EquineNetworkLLCMember	mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Hotels, Gaming & Leisure	Hotels, Gaming & Leisure
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Fair Value		$ 115	$ 109
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, One, due 12/31/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			10.24%
Acquisition Date			Dec. 31, 2020
Maturity			Dec. 31, 2025
Principal			$ 1,719
Fair Value			$ 1,709
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, Two, due 12/31/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			10.24%
Acquisition Date			Jan. 29, 2021
Maturity			Dec. 31, 2025
Principal			$ 780
Fair Value			$ 775
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc. ( Revolver), Senior Secured Loans, due 4/28/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc., Senior Secured Loans, due 4/27/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Express Wash Acquisition Company, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		8%	8%
Acquisition Date		Dec. 28, 2020	Dec. 28, 2020
Fair Value		$ 75	$ 118
Investment, Non-income Producing [true false]		false	false
Number of shares held		121,311
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC (Revolver), Senior Secured Loans, due 7/14/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	10.83%
Acquisition Date		Jul. 14, 2022	Jul. 14, 2022
Maturity		Jul. 14, 2028	Jul. 14, 2028
Principal		$ 379	$ 379
Fair Value		$ 209	$ 208
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, One, Due 7/14/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Jul. 14, 2022	Jul. 14, 2022
Maturity		Jul. 14, 2028	Jul. 14, 2028
Principal		$ 7,067	$ 8,160
Fair Value		$ 7,067	$ 8,119
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, Two, Due 7/14/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExpressWashAcquisitionCompanyLLCMember	mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	10.43%
Acquisition Date		Jul. 14, 2022	Jul. 14, 2022
Maturity		Jul. 14, 2028	Jul. 14, 2028
Principal		$ 1,517	$ 1,528
Fair Value		$ 1,517	$ 1,521
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Familia Dental Group Holdings, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Familia Dental Group Holdings, L L C [ Member]	Familia Dental Group Holdings, L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Apr. 08, 2016	Apr. 08, 2016
Principal		$ 0
Fair Value		$ 2,351	$ 2,625	2,508	1,919
Investment, Non-income Producing [true false]		true	true
Number of shares held		1,212
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Junior Secured Loans, due 6/28/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:FloridaEastCoastIndustriesLLCMember	mrcc:FloridaEastCoastIndustriesLLCMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]	Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		16%	16%
Acquisition Date		Aug. 09, 2021	Aug. 09, 2021
Maturity		Jun. 28, 2024	Jun. 28, 2024
Principal		$ 845	$ 1,778
Fair Value		$ 845	$ 1,784
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Senior Secured Loans, due 6/28/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FloridaEastCoastIndustriesLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			10.50%
Acquisition Date			Aug. 09, 2021
Maturity			Jun. 28, 2024
Principal			$ 617
Fair Value			$ 619
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Forman Mills, Inc, Equity Securities, Warrants
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FormanMillsInc.Member
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Jan. 14, 2020
Maturity			Jan. 14, 2029
Fair Value			$ 155
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, One, due 4/30/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FormanMillsIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			9.50%
Interest Rate, Paid in Cash			11.94%
Interest Rate, Paid in Kind			2%
Acquisition Date			Jan. 14, 2020
Maturity			Apr. 30, 2024
Principal			$ 1,275
Fair Value			$ 1,253
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, Two, due 4/30/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FormanMillsIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			9.50%
Interest Rate, Paid in Cash			11.94%
Interest Rate, Paid in Kind			2%
Acquisition Date			Oct. 04, 2016
Maturity			Apr. 30, 2024
Principal			$ 6,909
Fair Value			$ 6,698
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Forman Mills, Inc., Senior Secured Loans, due 6/20/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:FormanMillsInc.Member
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Retail
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		3.90%
Interest Rate, Paid in Kind		3.90%
Acquisition Date		Apr. 27, 2023
Maturity		Jun. 20, 2028
Principal		$ 1,308
Fair Value		$ 965
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: GC Champion Acquisition LLC (Delayed Draw), Senior Notes, Due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.75%
Interest Rate			11.15%
Acquisition Date			Aug. 19, 2022
Maturity			Aug. 18, 2028
Principal			$ 704
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.75%
Interest Rate			11.15%
Acquisition Date			Aug. 19, 2022
Maturity			Aug. 18, 2028
Principal			$ 2,528
Fair Value			$ 2,503
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, One, Due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.75%
Interest Rate		11.78%
Acquisition Date		Aug. 19, 2022
Maturity		Aug. 18, 2028
Principal		$ 2,535
Fair Value		$ 2,513
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Two, Due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.25%
Interest Rate		11.28%
Acquisition Date		Aug. 19, 2022
Maturity		Aug. 18, 2028
Principal		$ 704
Fair Value		$ 698
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: GC Champion Acquisition Llc Senior Notes Three Due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:GCChampionAcquisitionLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.50%
Interest Rate		11.87%
Acquisition Date		Aug. 01, 2023
Maturity		Aug. 18, 2028
Principal		$ 2,112
Fair Value		$ 2,112
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: H A H Group Holding Company L L C, Senior Secured Loans, due 10/29/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H A L O Buyer, Inc., Senior Secured Loans, due 6/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans , Two
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		9.46%	12.50%
Interest Rate, Paid in Kind		17.96%	16.62%
Acquisition Date		Oct. 20, 2017	Oct. 20, 2017
Principal		$ 4,758	$ 4,758
Fair Value		$ 6,094	$ 5,805	5,708	5,420
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans, One
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		9.46%	12.50%
Interest Rate, Paid in Kind		17.96%	16.62%
Acquisition Date		Oct. 20, 2017	Oct. 20, 2017
Principal		$ 13,242	$ 13,242
Fair Value		$ 16,962	$ 16,159	15,888	15,084
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc. ( Revolver), Senior Secured Loans, due 7/9/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HS4AcquisitioncoIncMember	mrcc:HS4AcquisitioncoIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.85%	6.75%
Interest Rate		12.17%	11.14%
Acquisition Date		Jul. 09, 2019	Jul. 09, 2019
Maturity		Jul. 09, 2025	Jul. 09, 2025
Principal		$ 817	$ 817
Fair Value		$ 530	$ 407
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc., Senior Secured Loans, due 7/9/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HS4AcquisitioncoIncMember	mrcc:HS4AcquisitioncoIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.85%	6.75%
Interest Rate		12.17%	11.14%
Acquisition Date		Jul. 09, 2019	Jul. 09, 2019
Maturity		Jul. 09, 2025	Jul. 09, 2025
Principal		$ 9,824	$ 9,899
Fair Value		$ 9,804	$ 9,855
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, One, due 12/13/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, Two, due 12/13/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Hastings Manufacturing Company (Revolver), Senior Secured Loans, Due 12/31/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.60%
Interest Rate		12.92%
Acquisition Date		Mar. 29, 2023
Maturity		Dec. 31, 2024
Principal		$ 691
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, One, Due 12/31/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.60%
Interest Rate		12.92%
Acquisition Date		Apr. 24, 2018
Maturity		Dec. 31, 2024
Principal		$ 1,858
Fair Value		$ 1,858
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, Two, Due 12/31/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]		us-gaap:SeniorSubordinatedLoansMember
Investment, Industry Sector [Extensible Enumeration]		Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.60%
Interest Rate		12.92%
Acquisition Date		Mar. 29, 2023
Maturity		Dec. 31, 2024
Principal		$ 665
Fair Value		$ 665
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Hastings Manufacturing Company, Senior Secured Loans, due 4/24/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HastingsManufacturingCompanyMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.25%
Interest Rate			11.64%
Acquisition Date			Apr. 24, 2018
Maturity			Apr. 24, 2023
Principal			$ 2,026
Fair Value			$ 2,026
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: I D I G Parent, L L C, Equity Securities, Common stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		I D I G Parent, L L C [ Member]	I D I G Parent, L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jan. 04, 2021	Jan. 04, 2021
Fair Value		$ 287	$ 324
Investment, Non-income Producing [true false]		true	true
Number of shares held			245,958
Investment, Identifier [Axis]: I N H Buyer, Inc., Senior Secured Loans, due 6/28/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:INHBuyerInc.Member	mrcc:INHBuyerInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate, Paid in Cash		8.99%
Interest Rate, Paid in Kind		3.50%	3.50%
Acquisition Date		Jun. 30, 2021	Jun. 30, 2021
Maturity		Jun. 28, 2028	Jun. 28, 2028
Principal		$ 3,006	$ 2,950
Fair Value		$ 2,925	$ 2,832
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: In Mobi Pte, Ltd, Media: Equity Securities, due 9/18/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:InMobiPteLtdMember	mrcc:InMobiPteLtdMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		International	International
Acquisition Date		Sep. 18, 2015	Sep. 18, 2015
Maturity		Sep. 18, 2025	Sep. 18, 2025
Fair Value		$ 1,965	$ 1,816
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Independence Buyer, Inc, Senior Secured Loans, due 8/3/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IndependenceBuyerInc.Member	mrcc:IndependenceBuyerInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.90%	5.50%
Interest Rate		11.27%	9.74%
Acquisition Date		Aug. 03, 2021	Aug. 03, 2021
Maturity		Aug. 03, 2026	Aug. 03, 2026
Principal		$ 5,513	$ 5,940
Fair Value		$ 5,417	$ 5,866
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Independence Buyer, Inc. ( Revolver), Senior Secured Loans, due 8/3/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IndependenceBuyerInc.Member	mrcc:IndependenceBuyerInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.90%	5.50%
Interest Rate		11.27%	9.74%
Acquisition Date		Aug. 03, 2021	Aug. 03, 2021
Maturity		Aug. 03, 2026	Aug. 03, 2026
Principal		$ 1,423	$ 1,423
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Independence Buyer, Inc., Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IndependenceBuyerInc.Member	mrcc:IndependenceBuyerInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 03, 2021	Aug. 03, 2021
Fair Value		$ 68	$ 102
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Intermedia Holdings, Inc., Senior Secured Loans, due 7/21/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: J2 B W A Funding L L C, Equity Securities
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:J2BWAFundingLLCMember	mrcc:J2BWAFundingLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 24, 2020	Dec. 24, 2020
Fair Value		$ 27
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: J2 BWA Funding LLC (Delayed Draw), Senior Notes, Due 12/24/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:J2BWAFundingLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			9%
Acquisition Date			Dec. 24, 2020
Maturity			Dec. 24, 2026
Principal			$ 2,750
Fair Value			$ 1,298
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: J2 Bwa Funding Llc Revolver Senior Notes Due 12/24/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:J2BWAFundingLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate, Paid in Kind		10%
Acquisition Date		Dec. 24, 2020
Maturity		Dec. 24, 2026
Principal		$ 2,750
Fair Value		$ 1,550
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Revolver) Senior Secured Loans Due
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7%
Interest Rate		12.37%
Acquisition Date		Feb. 01, 2023
Maturity		Feb. 01, 2029
Principal		$ 813
Fair Value		$ 244
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) Senior Secured Loans Due 2/1/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7%
Interest Rate		12.37%
Acquisition Date		Feb. 01, 2023
Maturity		Feb. 01, 2029
Principal		$ 4,988
Fair Value		$ 4,988
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: KL Moon Acquisition, LLC (fka Spectrum Science Communications, LLC), Equity Securities, Common Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jan. 31, 2023
Fair Value		$ 500
Investment, Identifier [Axis]: Kar Wash Holdings LLC Equity Securities Series A Preferred Stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jun. 27, 2023
Fair Value		$ 11
Investment, Non-income Producing [true false]		true
Number of shares held		8,619
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6%
Interest Rate		12.04%	10.77%
Acquisition Date		Aug. 03, 2022	Aug. 03, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 2,653	$ 2,667
Fair Value		$ 2,229	$ 1,782
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Revolver), Senior Secured Loans, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6%
Interest Rate		12.04%	10.77%
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 571	$ 572
Fair Value			$ 303
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kar Wash Holdings, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Fair Value		$ 61	$ 111
Investment, Non-income Producing [true false]		true	true
Number of shares held		99,807
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, One, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6%
Interest Rate		12.01%	9.82%
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 1,580	$ 1,592
Fair Value		$ 1,576	$ 1,585
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, Two, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KarWashHoldingsLLCMember	mrcc:KarWashHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6%
Interest Rate		12.01%	10.35%
Acquisition Date		Feb. 28, 2022	Feb. 28, 2022
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 1,132	$ 1,140
Fair Value		$ 1,129	$ 1,135
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Keystone Purchaser, L L C, Senior Secured Loans, due 5/7/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, One, Due 12/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.65%
Interest Rate			11.12%
Acquisition Date			Dec. 09, 2022
Maturity			Dec. 11, 2028
Principal			$ 720
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, Two, Due 12/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember	mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.15%	6.65%
Interest Rate		11.48%	11.12%
Acquisition Date		Dec. 09, 2022	Dec. 09, 2022
Maturity		Dec. 11, 2028	Dec. 11, 2028
Principal		$ 600	$ 600
Fair Value		$ 131
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Revolver), Senior Secured Loans, Due 12/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember	mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.15%	6.65%
Interest Rate		11.48%	11.12%
Acquisition Date		Dec. 09, 2022	Dec. 09, 2022
Maturity		Dec. 11, 2028	Dec. 11, 2028
Principal		$ 240	$ 240
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, , Senior Secured Loans, Due 12/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.65%
Interest Rate			11.12%
Acquisition Date			Dec. 09, 2022
Maturity			Dec. 11, 2028
Principal			$ 600
Fair Value			$ 588
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, One Due 12/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.15%
Interest Rate		11.40%
Acquisition Date		Dec. 09, 2022
Maturity		Dec. 11, 2028
Principal		$ 597
Fair Value		$ 591
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, Two, Due 12/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KingsleyGatePartnersLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.15%
Interest Rate		11.40%
Acquisition Date		Dec. 09, 2022
Maturity		Dec. 11, 2028
Principal		$ 192
Fair Value		$ 190
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Kl Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Delayed Draw) Senior Secured Loans Due
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KlMoonAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7%
Interest Rate		12.37%
Acquisition Date		Feb. 01, 2023
Maturity		Feb. 01, 2029
Principal		$ 1,702
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: L S C S Holdings, Inc., Senior Secured Loans, due 12/15/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: L V F Holdings, Inc. ( Revolver), Senior Secured Loans, due 6/10/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LXJTIntermediateHoldingsIncMember	mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.15%	6.25%
Interest Rate		11.54%	10.98%
Acquisition Date		Jun. 10, 2021	Jun. 10, 2021
Maturity		Jun. 10, 2027	Jun. 10, 2027
Principal		$ 238	$ 238
Fair Value			$ 152
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, ( Delayed Draw) due 6/10/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.25%
Interest Rate			8.45%
Acquisition Date			Jun. 10, 2021
Maturity			Jun. 10, 2027
Principal			$ 344
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, One, due 6/10/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LVFHoldingsIncMember	mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.15%	6.25%
Interest Rate		11.54%	8.45%
Acquisition Date		Jun. 10, 2021	Jun. 10, 2021
Maturity		Jun. 10, 2027	Jun. 10, 2027
Principal		$ 1,470	$ 1,481
Fair Value		$ 1,433	$ 1,437
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, Two, due 6/10/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LVFHoldingsIncMember	mrcc:LVFHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.15%	6.25%
Interest Rate		11.54%	8.45%
Acquisition Date		Jun. 10, 2021	Jun. 10, 2021
Maturity		Jun. 10, 2027	Jun. 10, 2027
Principal		$ 1,407	$ 1,418
Fair Value		$ 1,372	$ 1,375
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc. ( Revolver), Senior Secured Loans, due 3/11/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LXJTIntermediateHoldingsIncMember	mrcc:LXJTIntermediateHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Mar. 11, 2020	Mar. 11, 2020
Maturity		Mar. 11, 2025	Mar. 11, 2025
Principal		$ 833	$ 833
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc., Senior Secured Loans, due 3/11/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LXJTIntermediateHoldingsIncMember	mrcc:LXJTIntermediateHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Mar. 11, 2020	Mar. 11, 2020
Maturity		Mar. 11, 2025	Mar. 11, 2025
Principal		$ 5,393	$ 5,468
Fair Value		$ 5,366	$ 5,394
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Laseraway Intermediate Holdings I I, L L C, Senior Secured Loans, due 10/14/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 8/2/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.75%
Interest Rate			9.49%
Acquisition Date			Aug. 02, 2021
Maturity			Aug. 02, 2027
Principal			$ 1,400
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Revolver), Senior Secured Loans, due 8/2/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftedTrucksHoldingsLLCMember	mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.75%	5.75%
Interest Rate		11.14%	9.49%
Acquisition Date		Aug. 02, 2021	Aug. 02, 2021
Maturity		Aug. 02, 2027	Aug. 02, 2027
Principal		$ 1,667	$ 1,667
Fair Value		$ 544
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftedTrucksHoldingsLLCMember	mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 02, 2021	Aug. 02, 2021
Fair Value		$ 74	$ 78
Investment, Non-income Producing [true false]		false	true
Number of shares held		111,111
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Senior Secured Loans, due 8/2/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftedTrucksHoldingsLLCMember	mrcc:LiftedTrucksHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.85%	5.75%
Interest Rate		11.10%	9.49%
Acquisition Date		Aug. 02, 2021	Aug. 02, 2021
Maturity		Aug. 02, 2027	Aug. 02, 2027
Principal		$ 6,878	$ 6,930
Fair Value		$ 6,740	$ 6,840
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Liftforward SPV II LLC Senior Secured Loans Due 9/29/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LiftforwardSPVIILLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate, Paid in Kind		16.18%
Acquisition Date		Nov. 10, 2016
Maturity		Mar. 31, 2024
Principal		$ 243
Fair Value		$ 223
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Liftforward SPV II, LLC, Senior Secured Loans, due 3/31/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftforwardSPVIILLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			10.75%
Interest Rate			15.14%
Acquisition Date			Nov. 10, 2016
Maturity			Mar. 31, 2023
Principal			$ 413
Fair Value			$ 403
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Lightbox Intermediate, L. P., Senior Secured Loans, due 5/11/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Luxury Optical Holdings Co., Equity Securities
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LuxuryOpticalHoldingsCo.Member
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			Retail
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Sep. 12, 2014
Fair Value			$ 209
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C ( Delayed Draw), Senior Secured Loans Due 1/26/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		15%	15%
Interest Rate, Paid in Kind		20.25%	18.74%
Acquisition Date		Apr. 26, 2021	Apr. 26, 2021
Maturity		Jan. 26, 2024	Jan. 26, 2024
Principal		$ 2,903	$ 1,793
Fair Value		$ 2,903	$ 1,000	957	850
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securites
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 11, 2019	Jun. 11, 2019
Principal		$ 0
Fair Value		$ 1,232	$ 1,291
Investment, Non-income Producing [true false]		true	false
Percentage of equity interest			15.90%
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securities
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Fair Value		$ 1,232	$ 1,291	$ 751	644
Percentage of equity interest		15.90%		15.90%
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Senior Secured Loans Due 1/26/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	mrcc:HFZCapitalGroupLLCMember	mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		London Interbank Offered Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		15%	15%
Interest Rate, Paid in Kind		20.53%	18.74%
Acquisition Date		Jan. 26, 2021	Jan. 26, 2021
Maturity		Jan. 26, 2024	Jan. 26, 2024
Principal		$ 9,732	$ 8,421
Fair Value		$ 9,732	$ 8,421	$ 8,057	7,154
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C ( Revolver), Senior Secured Loans, due 11/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Feb. 28, 2020	Feb. 28, 2020
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 1,784	$ 1,784
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C , Equity Securities, Class A-2 units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Feb. 28, 2020	Feb. 28, 2020
Fair Value		$ 432	$ 204
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, One, due 11/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Dec. 29, 2021	Feb. 28, 2020
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 968	$ 9,722
Fair Value		$ 973	$ 9,736
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, Two, due 11/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Dec. 29, 2021	Dec. 29, 2021
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 2,943	$ 2,972
Fair Value		$ 2,957	$ 2,977
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: M R C C Senior Loan Fund I, L L C, Equity Securities
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Controlled affiliate company investments	Controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		MRCC Senior Loan Fund I, LLC	MRCC Senior Loan Fund I, LLC
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		mrcc:InvestmentFundsVehiclesMember	mrcc:InvestmentFundsVehiclesMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 31, 2017	Oct. 31, 2017
Principal		$ 0
Fair Value		$ 33,269	$ 35,509	36,544	41,125
Investment, Non-income Producing [true false]		false	false
Percentage of equity interest		50%	50%
Investment, Identifier [Axis]: M V Receivables I I, L L C ( Delayed Draw), Senior Secured Loans, due 7/29/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			9.75%
Interest Rate			13.87%
Acquisition Date			Jul. 29, 2021
Maturity			Jul. 29, 2026
Principal			$ 8,115
Fair Value			$ 7,968
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Common units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MVReceivablesIILLCMember	mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jul. 29, 2021	Jul. 29, 2021
Fair Value			$ 1,154
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Due 7/28/2031, Warrants
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MVReceivablesIILLCMember	mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jul. 28, 2021	Jul. 28, 2021
Maturity		Jul. 28, 2031	Jul. 28, 2031
Fair Value			$ 1,655
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: M V Receivables I I, L L C, Senior Secured Loans, due 7/29/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MVReceivablesIILLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		9.75%
Interest Rate		15.08%
Acquisition Date		Jul. 29, 2021
Maturity		Jul. 29, 2026
Principal		$ 8,100
Fair Value		$ 8,017
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: MC Asset Management (Corporate), LLC, Senior Secured Loans, Two, Due 1/26/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCAssetManagementCorporateLLCMember
Fair Value		$ 2,903	$ 1,000
Investment, Identifier [Axis]: MCP Shaw Acquisitionco, LLC, Senior Secured Loans, Three, due 11/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCPShawAcquisitioncoLLCMember	mrcc:MCPShawAcquisitioncoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.26%	6.50%
Interest Rate		11.65%	11.06%
Acquisition Date		Feb. 28, 2020	Dec. 29, 2021
Maturity		Nov. 28, 2025	Nov. 28, 2025
Principal		$ 9,624	$ 978
Fair Value		$ 9,624	$ 979
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: MEI Buyer LLC (Delayed Draw), Senior Secured Loans, due 6/29/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.50%
Interest Rate		11.82%
Acquisition Date		Jun. 30, 2023
Maturity		Jun. 29, 2029
Principal		$ 317
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: MEI Buyer LLC (Revolver), Senior Secured Loans, due 6/29/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.50%
Interest Rate		11.82%
Acquisition Date		Jun. 30, 2023
Maturity		Jun. 29, 2029
Principal		$ 410
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: MEI Buyer LLC, Equity Securities, Common Stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jun. 30, 2023
Fair Value		$ 138
Investment, Non-income Producing [true false]		true
Number of shares held		155
Investment, Identifier [Axis]: MEI Buyer LLC, Senior Secured Loans, due 6/29/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MeiBuyerLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.50%
Interest Rate		11.82%
Acquisition Date		Jun. 30, 2023
Maturity		Jun. 29, 2029
Principal		$ 2,000
Fair Value		$ 2,015
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Delayed Draw), Senior Secured Loans, due 1/7/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Revolver), Senior Secured Loans, due 1/7/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C, Senior Secured Loans, due 1/7/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mammoth Holdings, LLC (Revolver), Senior Secured Loans, Due, 10/16/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MammothHoldingsLLCMember	mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6%
Interest Rate		12.01%	9.82%
Acquisition Date		Oct. 16, 2018	Oct. 16, 2018
Maturity		Oct. 16, 2024	Oct. 16, 2024
Principal		$ 657	$ 657
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Due 10/16/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.76%
Interest Rate		12.01%
Acquisition Date		Jan. 25, 2023
Maturity		Oct. 16, 2024
Principal		$ 13,770
Fair Value		$ 13,728
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Four, due 10/16/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			9.82%
Acquisition Date			Jun. 15, 2021
Maturity			Oct. 16, 2024
Principal			$ 1,633
Fair Value			$ 1,630
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, One, due 10/16/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			9.82%
Acquisition Date			Oct. 16, 2018
Maturity			Oct. 16, 2024
Principal			$ 1,920
Fair Value			$ 1,917
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Three, due 10/16/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			9.82%
Acquisition Date			Mar. 12, 2021
Maturity			Oct. 16, 2024
Principal			$ 6,291
Fair Value			$ 6,282
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Two, due 10/16/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate			9.82%
Acquisition Date			Oct. 16, 2018
Maturity			Oct. 16, 2024
Principal			$ 4,031
Fair Value			$ 4,025
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation ( Revolver), Senior Secured Loans, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.85%
Acquisition Date			Oct. 20, 2020
Maturity			Oct. 20, 2025
Principal			$ 269
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Four, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.85%
Acquisition Date			Nov. 23, 2021
Maturity			Oct. 20, 2025
Principal			$ 214
Fair Value			$ 213
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, One, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.85%
Acquisition Date			Oct. 20, 2020
Maturity			Oct. 20, 2025
Principal			$ 3,430
Fair Value			$ 3,414
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Three, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.85%
Acquisition Date			May 10, 2022
Maturity			Oct. 20, 2025
Principal			$ 2,669
Fair Value			$ 2,656
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Two, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.85%
Acquisition Date			Nov. 23, 2021
Maturity			Oct. 20, 2025
Principal			$ 320
Fair Value			$ 318
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: MarkLogic Corporation, Equity Securities, Class A Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MarkLogicCorporationMember
Investment, Type [Extensible Enumeration]			Equity Securities
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Oct. 20, 2020
Fair Value			$ 426
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: Mavenir Systems, Inc., Senior Secured Loans, due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mc Kissock Investment Holdings, L L C, Senior Secured Loans, due 3/9/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Medallia, Inc, Senior Secured Loans, due 10/27/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MedalliaIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6.50%
Interest Rate, Paid in Kind		11.42%	10.88%
Acquisition Date		Aug. 15, 2022	Aug. 15, 2022
Maturity		Oct. 27, 2028	Oct. 27, 2028
Principal		$ 2,140	$ 2,049
Fair Value		$ 2,150	$ 2,041
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mindbody, Inc. ( Revolver) (f), Senior Secured Loans, due 2/14/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MindbodyIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.15%	7%
Interest Rate			11.73%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Feb. 14, 2025	Feb. 14, 2025
Principal		$ 667	$ 667
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, One, due 2/14/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MindbodyIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.15%	7%
Interest Rate		12.52%	11.73%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Feb. 14, 2025	Feb. 14, 2025
Principal		$ 6,536	$ 6,536
Fair Value		$ 6,526	$ 6,526
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, Two, due 2/14/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MindbodyIncMember	mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.15%	7%
Interest Rate		12.52%	11.73%
Acquisition Date		Sep. 22, 2021	Sep. 22, 2021
Maturity		Feb. 14, 2025	Feb. 14, 2025
Principal		$ 474	$ 674
Fair Value		$ 473	$ 673
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Minotaur Acquisition, Inc., Senior Secured Loans, due 3/27/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, One 12/30/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.26%
Interest Rate, Paid in Cash		8.65%
Interest Rate, Paid in Kind		5%
Acquisition Date		Nov. 02, 2018
Maturity		Dec. 30, 2024
Principal		$ 6,059
Fair Value		$ 6,059
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, Two 12/30/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.26%
Interest Rate, Paid in Kind		5%
Acquisition Date		Jul. 27, 2023
Maturity		Dec. 30, 2024
Principal		$ 53
Fair Value		$ 53
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mnine Holdings, Inc (Revolver), Senior Secured Loans, Due 12/30/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.26%
Interest Rate		12.65%
Interest Rate, Paid in Cash		8.62%
Acquisition Date		Aug. 09, 2022
Maturity		Dec. 30, 2024
Principal		$ 533
Fair Value		$ 533
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Mnine Holdings, Inc, Senior Secured Loans, Due 12/30/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			8%
Interest Rate, Paid in Cash			7.84%
Interest Rate, Paid in Kind			5%
Acquisition Date			Nov. 02, 2018
Maturity			Dec. 30, 2023
Principal			$ 5,492
Fair Value			$ 5,492
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mnine Holdings, Inc. (Revolver), Senior Secured Loans, due 12/30/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Spread			8%
Interest Rate, Paid in Cash			7.84%
Interest Rate, Paid in Kind			5%
Acquisition Date			Aug. 09, 2022
Maturity			Dec. 30, 2023
Principal			$ 533
Fair Value		$ 533	$ 214	240
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Mnine Holdings, Inc., Equity Securities, Class B units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 30, 2020	Jun. 30, 2020
Principal		$ 0
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due 12/30/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Fair Value		$ 53		6,001	5,771
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due Two 12/30/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Fair Value		$ 6,059	$ 5,492
Investment, Identifier [Axis]: Money Lion, Inc. ( Delayed Draw), Junior Secured Loans, due 3/24/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]			Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]			Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			9.25%
Interest Rate			14.07%
Acquisition Date			Mar. 25, 2022
Maturity			Mar. 24, 2026
Principal			$ 1,500
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 10/16/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		5.75%
Interest Rate		14.25%
Acquisition Date		Aug. 27, 2021
Maturity		Oct. 16, 2023
Principal		$ 375
Fair Value		$ 379
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 3/24/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MoneyLionIncMember	mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]	Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		9.51%	9.25%
Interest Rate		14.90%	14.07%
Acquisition Date		Mar. 25, 2022	Mar. 25, 2022
Maturity		Mar. 24, 2026	Mar. 24, 2026
Principal		$ 5,250	$ 5,250
Fair Value		$ 5,275	$ 5,165
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 5/1/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MoneyLionIncMember
Investment, Type [Extensible Enumeration]			Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]			Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]			us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.75%
Interest Rate			13.25%
Acquisition Date			Aug. 27, 2021
Maturity			May 01, 2023
Principal			$ 1,500
Fair Value			$ 1,498
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: N C B P Property, L L C, Senior Secured Loans, due 12/16/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NCBPPropertyLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			FIRE Real Estate Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			9.50%
Interest Rate			13.62%
Acquisition Date			Dec. 18, 2020
Maturity			Jun. 16, 2023
Principal			$ 1,950
Fair Value			$ 1,955
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: N E C B Collections, L L C ( Revolver), Senior Secured Loans
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		London Interbank Offered Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		11%	11%
Interest Rate, Paid in Kind		16.94%	14.61%
Acquisition Date		Jun. 25, 2019	Jun. 25, 2019
Principal		$ 1,356	$ 1,356
Fair Value		$ 424	$ 382	426	632
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: N E C B Collections, L L C, Equity Securities
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jun. 21, 2019	Jun. 21, 2019
Principal		$ 0
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Delayed Draw), Senior Secured Loans, Due 10/4/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.65%	6%
Interest Rate		11.04%	10.59%
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Maturity		Oct. 04, 2028	Oct. 04, 2028
Principal		$ 778	$ 778
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Revolver), Senior Secured Loans, Due 10/4/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread			6%
Interest Rate			10.59%
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Maturity		Oct. 04, 2028	Oct. 04, 2028
Principal		$ 438	$ 438
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Equity Securities, Common Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Fair Value		$ 370	$ 327
Investment, Non-income Producing [true false]			true
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Senior Secured Loans, Due 10/4/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NqPeProjectColosseumMidcoInc.Member	mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.65%	6%
Interest Rate		11.04%	10.59%
Acquisition Date		Oct. 04, 2022	Oct. 04, 2022
Maturity		Oct. 04, 2028	Oct. 04, 2028
Principal		$ 3,474	$ 3,500
Fair Value		$ 3,508	$ 3,430
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, One, Due 8/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.43%	11.22%
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 3,930	$ 3,960
Fair Value		$ 3,962	$ 4,039
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, Two, Due 8/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.43%	11.22%
Acquisition Date		Aug. 26, 2022	Aug. 26, 2022
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 4,684	$ 4,719
Fair Value		$ 4,721	$ 4,813
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits LLC Delayed Draw, Senior Secured Loans Due 8/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.43%	11.22%
Acquisition Date		Aug. 26, 2022	Aug. 26, 2022
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 5,078	$ 5,089
Fair Value		$ 5,119	$ 961
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits, L L C (Revolver), Senior Secured Loans, Due 8/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.43%	11.42%
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Maturity		Aug. 26, 2027	Aug. 26, 2027
Principal		$ 2,222	$ 2,222
Fair Value		$ 889	$ 889
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, One, Series B units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		5%	5%
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Fair Value		$ 730	$ 934
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, Two, common units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NationsBenefitsLLCMember	mrcc:NationsBenefitsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 20, 2021	Aug. 20, 2021
Fair Value			$ 66
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Natus Medical Incorporated, Senior Secured Loans, due 7/20/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Nearly Natural Inc. Senior Secured Loans One due 3/29/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		11.50%
Interest Rate, Paid in Cash		12.89%
Acquisition Date		Dec. 15, 2017
Maturity		Mar. 29, 2024
Principal		$ 6,545
Fair Value		$ 6,134
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Four, due 3/29/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		11.50%
Interest Rate, Paid in Cash		12.89%
Interest Rate, Paid in Kind		4%
Acquisition Date		Aug. 28, 2019
Maturity		Mar. 29, 2024
Principal		$ 1,847
Fair Value		$ 1,731
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Three, due 3/29/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		11.50%
Interest Rate, Paid in Cash		12.89%
Acquisition Date		Feb. 16, 2021
Maturity		Mar. 29, 2024
Principal		$ 3,084
Fair Value		$ 2,890
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Two, due 3/29/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		11.50%
Interest Rate, Paid in Cash		12.89%
Interest Rate, Paid in Kind		4%
Acquisition Date		Sep. 22, 2020
Maturity		Mar. 29, 2024
Principal		$ 1,696
Fair Value		$ 1,589
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, One, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalIncMember	mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Wholesale	Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 15, 2017	Dec. 15, 2017
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, Two, Class A A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalIncMember	mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Wholesale	Wholesale
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 27, 2021	Aug. 27, 2021
Fair Value		$ 2
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Nearly Natural, Inc. (Revolver), Senior Secured Loans, due 3/29/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NearlyNaturalInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		11.50%
Interest Rate, Paid in Cash		12.89%
Acquisition Date		Dec. 15, 2017
Maturity		Mar. 29, 2024
Principal		$ 2,608
Fair Value		$ 2,444
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Nearly Natural, Inc.( Revolver), Senior Secured loans, due 12/15/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			11.50%
Interest Rate, Paid in Cash			12.32%
Interest Rate, Paid in Kind			4%
Acquisition Date			Dec. 15, 2017
Maturity			Mar. 31, 2024
Principal			$ 2,505
Fair Value			$ 2,241
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Four, due 12/15/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			11.50%
Interest Rate, Paid in Cash			12.32%
Interest Rate, Paid in Kind			4%
Acquisition Date			Aug. 28, 2019
Maturity			Mar. 31, 2024
Principal			$ 1,868
Fair Value			$ 1,672
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, One, due 12/15/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			11.50%
Interest Rate, Paid in Cash			12.32%
Interest Rate, Paid in Kind		4%	4%
Acquisition Date			Dec. 15, 2017
Maturity			Mar. 31, 2024
Principal			$ 6,628
Fair Value			$ 5,931
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Three, due 12/15/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			11.50%
Interest Rate, Paid in Cash			12.32%
Interest Rate, Paid in Kind		4%	4%
Acquisition Date			Feb. 16, 2021
Maturity			Mar. 31, 2024
Principal			$ 3,115
Fair Value			$ 2,787
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Two, due 12/15/2022
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			11.50%
Interest Rate, Paid in Cash			12.32%
Interest Rate, Paid in Kind		4%	4%
Acquisition Date			Sep. 22, 2020
Maturity			Mar. 31, 2024
Principal			$ 1,714
Fair Value			$ 1,534
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Newforma, Inc. ( Revolver) (f), Senior Secured Loans, due 3/31/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.50%
Interest Rate			10.23%
Acquisition Date			Jun. 30, 2017
Maturity			Mar. 31, 2023
Principal			$ 1,250
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Newforma, Inc., Senior Secured Loans, due 3/31/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MedalliaIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.50%
Interest Rate			10.23%
Acquisition Date			Jun. 30, 2017
Maturity			Mar. 31, 2023
Principal			$ 938
Fair Value			$ 938
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: North Haven Spartan U S Holdco, L L C, Senior Secured Loans, due 6/6/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Delayed Draw), Senior Secured Loans, due, 10/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.50%
Interest Rate		11.44%	11.18%
Acquisition Date		Jul. 29, 2022	Jul. 29, 2022
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 1,056	$ 1,056
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Revolver), Senior Secured Loans, due, 10/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		12%	11.13%
Acquisition Date		Oct. 30, 2020	Oct. 30, 2020
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 416	$ 416
Fair Value		$ 409	$ 187
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, One, 10/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		11.99%	11.18%
Acquisition Date		Oct. 30, 2020	Oct. 30, 2020
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 2,431	$ 2,450
Fair Value		$ 2,390	$ 2,448
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, Two, 10/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.44%	10.41%
Acquisition Date		Jul. 29, 2022	Jul. 29, 2022
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 2,572	$ 2,592
Fair Value		$ 2,518	$ 2,575
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Four, due 10/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		11.99%	11.18%
Acquisition Date		Sep. 03, 2021	Sep. 03, 2021
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 1,423	$ 1,434
Fair Value		$ 1,399	$ 1,433
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Three, due 10/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenUSHCAcquisitionIncMember	mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	6.50%
Interest Rate		11.99%	11.18%
Acquisition Date		Mar. 12, 2021	Mar. 12, 2021
Maturity		Oct. 30, 2025	Oct. 30, 2025
Principal		$ 704	$ 710
Fair Value		$ 692	$ 709
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, One, due 6/29/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:OceanaAustralianFixedIncomeTrustMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			10.75%
Acquisition Date			Jun. 29, 2021
Maturity			Jun. 29, 2026
Principal			$ 3,084
Fair Value			$ 3,084
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, Two, due 2/25/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:OceanaAustralianFixedIncomeTrustMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			11.50%
Acquisition Date			Feb. 25, 2021
Maturity			Feb. 25, 2026
Principal			$ 7,321
Fair Value			$ 7,321
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, One, due 6/22/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, Two, due 6/22/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Onit, Inc., Unitranche Secured Loans, due 5/2/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:OnitInc.Member	mrcc:OnitInc.Member
Investment, Type [Extensible Enumeration]		Unitranche Debt [Member]	Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.50%	7.25%
Interest Rate		12.84%	12.30%
Acquisition Date		Dec. 20, 2021	Dec. 20, 2021
Maturity		May 02, 2025	May 02, 2025
Principal		$ 1,680	$ 1,680
Fair Value		$ 1,680	$ 1,663
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, One, due 10/21/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Three, due 10/21/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Two, due 10/21/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Output Services Group Inc. Senior Secured Loans Due 6/29/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P H Beauty Holdings I I I, I N C., Senior Secured Loans, due 9/26/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Four, Preferred units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Fair Value		$ 42	$ 46
Investment, Non-income Producing [true false]		false	false
Number of shares held		916
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, One, Preferred units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Fair Value		$ 268	$ 298
Investment, Non-income Producing [true false]		false	false
Number of shares held		5,680
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Three, Preferred units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Fair Value		$ 6	$ 7
Investment, Non-income Producing [true false]		false	false
Number of shares held		132
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Two, Preferred units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PKSHoldingsLLCMember	mrcc:PKSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		12%	12%
Acquisition Date		Nov. 30, 2017	Nov. 30, 2017
Fair Value		$ 41	$ 46
Investment, Non-income Producing [true false]		false	false
Number of shares held		5,714
Investment, Identifier [Axis]: P V H C Holding Corp, Senior Secured Loans, due 2/17/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Panda Acquisition, LLC, Senior Secured Loans, due 10/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PandaAcquisitionLlcMember	mrcc:PandaAcquisitionLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.35%	6.35%
Interest Rate		11.74%	10.28%
Acquisition Date		Dec. 20, 2022	Dec. 20, 2022
Maturity		Oct. 18, 2028	Oct. 18, 2028
Principal		$ 4,416	$ 4,500
Fair Value		$ 3,720	$ 3,690
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Paragon Healthcare Inc. Senior Secured Loan Due 1/19/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Delayed Draw Senior Secured Loans due 1/19/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Revolver Senior Secured Loan Due 1/19/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group), Senior Secured Loan due 8/2/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Five, due 12/28/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.76%
Interest Rate		12.01%
Acquisition Date		Apr. 05, 2023
Maturity		Dec. 28, 2026
Principal		$ 707
Fair Value		$ 708
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Four, due 12/28/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Feb. 11, 2022	Feb. 11, 2022
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 884	$ 884
Fair Value		$ 884	$ 878
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/28/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Dec. 28, 2018	Dec. 28, 2018
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 9,500	$ 9,500
Fair Value		$ 9,500	$ 9,443
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 03, 2023
Fair Value		$ 19
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Three, due 12/28/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Jan. 11, 2021	Jan. 11, 2021
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 1,326	$ 1,325
Fair Value		$ 1,326	$ 1,318
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Two, due 12/28/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	9.90%
Acquisition Date		Sep. 12, 2022	Sep. 12, 2022
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 530	$ 530
Fair Value		$ 530	$ 527
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc. ( Revolver), Senior Secured Loans, due 12/28/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.76%	6.50%
Interest Rate		12.01%	10.32%
Acquisition Date		Dec. 28, 2018	Dec. 28, 2018
Maturity		Dec. 28, 2026	Dec. 28, 2026
Principal		$ 442	$ 442
Fair Value		$ 442	$ 439
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc., Equity Securities, Class A Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PlanfulInc.Member	mrcc:PlanfulInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		8%	8%
Acquisition Date		Dec. 28, 2018	Dec. 28, 2018
Fair Value		$ 860	$ 563
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Planful, Inc., Equity Securities, Class B Units
Investments
Number of shares held		35,791
Investment, Identifier [Axis]: Polychem Acquisition, L L C, Senior Secured Loans, due 3/17/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Prototek LLC (Delayed Draw), Senior Secured Loans, Due 12/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PrototekLlcMember	mrcc:PrototekLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	6.50%
Interest Rate		12.32%	10.83%
Acquisition Date		Dec. 08, 2022	Dec. 08, 2022
Maturity		Dec. 08, 2027	Dec. 08, 2027
Principal		$ 768	$ 768
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Prototek LLC (Revolver), Senior Secured Loans, Due 12/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PrototekLlcMember	mrcc:PrototekLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	6.50%
Interest Rate		12.32%	10.83%
Acquisition Date		Dec. 08, 2022	Dec. 08, 2022
Maturity		Dec. 08, 2027	Dec. 08, 2027
Principal		$ 576	$ 576
Fair Value		$ 90
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Prototek LLC, Senior Secured Loans, Due 12/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PrototekLlcMember	mrcc:PrototekLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.10%	6.50%
Interest Rate		12.43%	10.83%
Acquisition Date		Dec. 08, 2022	Dec. 08, 2022
Maturity		Dec. 08, 2027	Dec. 08, 2027
Principal		$ 2,488	$ 2,500
Fair Value		$ 2,432	$ 2,425
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C ( Delayed Draw), Senior Secured Loans, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Environmental Industries
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.62%
Acquisition Date			Dec. 07, 2021
Maturity			Oct. 20, 2025
Principal			$ 1,772
Fair Value			$ 381
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securites, Two, Warrants
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 19, 2021	Oct. 19, 2021
Maturity		Mar. 17, 2028	Mar. 19, 2028
Fair Value		$ 185	$ 147
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securities, One, Warrants
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Oct. 19, 2020	Oct. 19, 2020
Maturity		Mar. 17, 2028	Mar. 19, 2028
Fair Value		$ 264	$ 210
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, One, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.50%
Interest Rate		11.94%	10.62%
Acquisition Date		Oct. 19, 2020	Oct. 19, 2020
Maturity		Oct. 20, 2025	Oct. 20, 2025
Principal		$ 854	$ 972
Fair Value		$ 854	$ 972
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Three, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.50%
Interest Rate		11.94%	10.62%
Acquisition Date		Dec. 07, 2021	Dec. 07, 2021
Maturity		Oct. 20, 2025	Oct. 20, 2025
Principal		$ 3,335	$ 3,796
Fair Value		$ 3,319	$ 3,781
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Two, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember	mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries	Environmental Industries
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.50%
Interest Rate		11.94%	10.62%
Acquisition Date		Oct. 19, 2020	Oct. 19, 2020
Maturity		Oct. 20, 2025	Oct. 20, 2025
Principal		$ 938	$ 1,068
Fair Value		$ 938	$ 1,067
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Quest Resource Management Group, LLC, Senior Secured Loans, Four, Due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:QuestResourceManagementGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Environmental Industries
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.61%
Interest Rate		11.94%
Acquisition Date		Dec. 07, 2021
Maturity		Oct. 20, 2025
Principal		$ 336
Fair Value		$ 335
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Radiology Partners, Inc., Senior Secured Loans, due 7/9/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Recorded Future, Inc, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Recorded Future, Inc [ Member]	Recorded Future, Inc [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Jul. 03, 2019	Jul. 03, 2019
Fair Value		$ 281	$ 225
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C ( Revolver), Senior Secured Loans, due 8/4/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RecycledPlasticsIndustriesLLCMember	mrcc:RecycledPlasticsIndustriesLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.85%	6.75%
Interest Rate		12.18%	10.87%
Acquisition Date		Aug. 04, 2021	Aug. 04, 2021
Maturity		Aug. 04, 2026	Aug. 04, 2026
Principal		$ 473	$ 473
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C, Senior Secured Loans, due 8/4/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RecycledPlasticsIndustriesLLCMember	mrcc:RecycledPlasticsIndustriesLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.85%	6.75%
Interest Rate		12.18%	10.87%
Acquisition Date		Aug. 04, 2021	Aug. 04, 2021
Maturity		Aug. 04, 2026	Aug. 04, 2026
Principal		$ 3,308	$ 3,456
Fair Value		$ 3,254	$ 3,370
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relativity O D A L L C ( Revolver), Senior Secured Loans, due 5/12/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelativityODALLCMember	mrcc:RelativityODALLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	7.50%
Interest Rate, Paid in Kind		11.92%	11.89%
Acquisition Date		May 12, 2021	May 12, 2021
Maturity		May 12, 2027	May 12, 2027
Principal		$ 180	$ 180
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relativity O D A L L C, Senior Secured Loans, due 5/12/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelativityODALLCMember	mrcc:RelativityODALLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.60%	7.50%
Interest Rate, Paid in Kind		11.92%	11.89%
Acquisition Date		May 12, 2021	May 12, 2021
Maturity		May 12, 2027	May 12, 2027
Principal		$ 2,107	$ 2,061
Fair Value		$ 2,110	$ 2,060
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Delayed Draw), Senior Secured Loans, due, 11/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.75%
Interest Rate			9.97%
Acquisition Date			Nov. 20, 2020
Maturity			Nov. 20, 2025
Principal			$ 778
Fair Value			$ 648
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Revolver), Senior Secured Loans, due, 11/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6%	5.75%
Interest Rate		11.43%	9.97%
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
Maturity		Nov. 20, 2025	Nov. 20, 2025
Principal		$ 316	$ 316
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, Class B common units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, preferred units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		12%	12%
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
Fair Value		$ 39	$ 36
Investment, Non-income Producing [true false]		true	false
Investment, Identifier [Axis]: Relevate Health Group, L L C, Senior Secured Loans, due, 11/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember	mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6%	5.75%
Interest Rate		11.43%	9.97%
Acquisition Date		Nov. 20, 2020	Nov. 20, 2020
Maturity		Nov. 20, 2025	Nov. 20, 2025
Principal		$ 654	$ 1,474
Fair Value		$ 652	$ 1,449
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Relevate Health Group, LLC, Senior Secured Loans, Two, Due 11/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RelevateHealthGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6%
Interest Rate		11.43%
Acquisition Date		Nov. 20, 2020
Maturity		Nov. 20, 2025
Principal		$ 1,463
Fair Value		$ 1,458
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Research Now Group, Inc. and Survey Sampling International, L L C, Senior Secured Loans, due 12/20/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Rockdale Blackhawk, L L C, Senior Secured Loans, no stated maturity
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RockdaleBlackhawkLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Acquisition Date			Mar. 31, 2015
Fair Value			$ 557
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Rockdale Blackhawk, LLC, Senior Secured Loans, due, 11/30/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RockdaleBlackhawkLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Mar. 31, 2015
Fair Value		$ 527
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Runner Buyer I N C., Senior Secured Loans, due 10/23/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S F R Holdco, L L C Equity Securities
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	S F R Holdco, L L C [ Member]	S F R Holdco, L L C [ Member]
Fair Value				3,900	3,900
Percentage of equity interest		24.40%
Investment, Identifier [Axis]: S F R Holdco, L L C, Junior Secured Loans Due 7/28/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		S F R Holdco, L L C [ Member]
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		mrcc:FinanceInsuranceAndRealEstateSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate		8%
Acquisition Date		Aug. 06, 2021
Maturity		Jul. 28, 2028
Principal		$ 5,850
Fair Value		$ 6,358	$ 5,850	5,850	5,850
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: S I R V A Worldwide Inc., Senior Secured Loans, due 8/4/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S T A T S Intermediate Holdings, L L C, Senior Secured Loans, due 7/10/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S W Ingredients Holdings, L L C, Senior Secured Loans, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: SFR Holdco, LLC, Equity Securities, 24.4% of Interest
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		S F R Holdco, L L C [ Member]	mrcc:SfrHoldcoLlcEquitySecurities24.4OfInterestMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Aug. 06, 2021	Aug. 06, 2021
Principal		$ 0
Fair Value		$ 4,239	$ 3,900
Investment, Non-income Producing [true false]		true	false
Percentage of equity interest			24.40%
Investment, Identifier [Axis]: Sandvine Corporation, Senior Secured Loans, due 10/31/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C ( Revolver), Senior Secured Loans, Due 8/9/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Second Avenue S F R Holdings I I L L C [ Member]	Second Avenue S F R Holdings I I L L C [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7%	7%
Interest Rate		12.33%	11.12%
Acquisition Date		Aug. 11, 2021	Aug. 11, 2021
Maturity		Aug. 09, 2024	Aug. 09, 2024
Principal		$ 4,875	$ 4,875
Fair Value		$ 4,761	$ 4,755	4,767	2,104
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C, Junior Secured Loans, Due 7/28/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Second Avenue S F R Holdings I I L L C [ Member]
Investment, Type [Extensible Enumeration]			Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]			FIRE Real Estate Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate			8%
Acquisition Date			Aug. 06, 2021
Maturity			Jul. 28, 2028
Principal			$ 5,850
Fair Value			$ 5,850
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Secretariat Advisors L L C, Senior Secured Loans, due 12/29/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Secretariat Advisors LLC, Senior Secured Loans, Two, due 12/29/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Five, due 9/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6%
Interest Rate		11.42%	10.40%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 1,524	$ 1,535
Fair Value		$ 1,524	$ 1,532
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Four, due 9/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 2,119	$ 2,135
Fair Value		$ 2,119	$ 2,131
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, One, due 9/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 3,353	$ 3,378
Fair Value		$ 3,353	$ 3,372
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Three, due 9/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Sep. 30, 2021	Sep. 30, 2021
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 7,840	$ 7,900
Fair Value		$ 7,840	$ 7,884
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Two, due 9/30/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecurityServicesAcquisitionSubCorpMember	mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.10%	6%
Interest Rate		11.42%	10.42%
Acquisition Date		Feb. 15, 2019	Feb. 15, 2019
Maturity		Sep. 30, 2026	Sep. 30, 2026
Principal		$ 2,412	$ 2,430
Fair Value		$ 2,412	$ 2,425
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran Bio Science, L L C ( Revolver), Senior Secured Loans, due 7/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.50%	9.96%
Interest Rate, Paid in Cash			7.86%
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Maturity		Jul. 08, 2027	Jul. 08, 2027
Principal		$ 444	$ 444
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran Bio Science, L L C, Equity Securities, common units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals	Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Fair Value		$ 737	$ 537
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Seran Bio Science, L L C, Senior Secured Loans, due 7/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.50%	9.96%
Acquisition Date		Dec. 31, 2020	Dec. 31, 2020
Maturity		Jul. 08, 2027	Jul. 08, 2027
Principal		$ 2,438	$ 2,456
Fair Value		$ 2,425	$ 2,435
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran BioScience, LLC (Delayed Draw), Senior Secured Loans, Due 7/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember	mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.70%	10.67%
Acquisition Date		Jul. 08, 2022	Jul. 08, 2022
Maturity		Jul. 08, 2027	Jul. 08, 2027
Principal		$ 2,762	$ 2,776
Fair Value		$ 2,527	$ 1,320
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Seran Bioscience Llc (Delayed Draw) One Senior Secured Loans Due 7/8/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SeranBioScienceLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.25%
Interest Rate		11.70%
Acquisition Date		Aug. 21, 2023
Maturity		Jul. 08, 2027
Principal		$ 1,444
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Service Max, Inc. ( Revolver) , Senior Secured Loans, due 11/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ServiceMaxIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6%
Interest Rate, Paid in Kind			10.27%
Acquisition Date			Nov. 01, 2021
Maturity			Nov. 01, 2027
Principal			$ 350
Fair Value			$ 175
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Service Max, Inc., Senior Secured Loans, due 11/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ServiceMaxIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7%
Interest Rate, Paid in Kind			11.12%
Acquisition Date			Nov. 01, 2021
Maturity			Nov. 01, 2027
Principal			$ 3,846
Fair Value			$ 3,884
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Sparq Holdings Inc. Delayed Draw Senior Secured Loans Due 6/15/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.25%
Interest Rate		11.64%
Acquisition Date		Jun. 16, 2023
Maturity		Jun. 15, 2029
Principal		$ 222
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Sparq Holdings Inc. Revolver Senior Secured Loans Due 6/15/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.25%
Interest Rate		11.64%
Acquisition Date		Jun. 16, 2023
Maturity		Jun. 15, 2029
Principal		$ 205
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Sparq Holdings Inc. Senior Secured Loans Due 6/15/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.25%
Interest Rate		11.64%
Acquisition Date		Jun. 16, 2023
Maturity		Jun. 15, 2029
Principal		$ 998
Fair Value		$ 998
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Sparq Holdings, Inc. Senior Secured Loans
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SparqHoldingsInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jun. 15, 2023
Fair Value		$ 305
Investment, Non-income Producing [true false]		false
Number of shares held		300,000
Investment, Identifier [Axis]: Spectrum Science Communications, L L C ( Revolver), Senior Secured Loans, due 1/25/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SpectrumScienceCommunicationsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.25%
Interest Rate			10.92%
Acquisition Date			Jan. 25, 2022
Maturity			Jan. 25, 2027
Principal			$ 200
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Spectrum Science Communications, L L C, Senior Secured Loans, due 1/25/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SpectrumScienceCommunicationsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.25%
Interest Rate			10.92%
Acquisition Date			Jan. 25, 2022
Maturity			Jan. 25, 2027
Principal			$ 995
Fair Value			$ 1,005
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Spherix Global Inc, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SpherixGlobalIncMember	mrcc:SpherixGlobalInc.Member
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Dec. 22, 2021	Dec. 22, 2021
Fair Value		$ 54	$ 63
Investment, Non-income Producing [true false]		true	true
Investment, Identifier [Axis]: Spherix Global Inc. ( Revolver), Senior Secured Loans, due, 12/22/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SpherixGlobalInc.Member	mrcc:SpherixGlobalIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.36%	6%
Interest Rate		13.69%	10.24%
Acquisition Date		Dec. 22, 2021	Dec. 22, 2021
Maturity		Dec. 22, 2026	Dec. 22, 2026
Principal		$ 122	$ 122
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Spherix Global Inc. , Senior Secured Loans, due, 12/22/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SpherixGlobalInc.Member	mrcc:SpherixGlobalIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.36%	6%
Interest Rate		13.69%	10.24%
Acquisition Date		Dec. 22, 2021	Dec. 22, 2021
Maturity		Dec. 22, 2026	Dec. 22, 2026
Principal		$ 1,084	$ 1,092
Fair Value		$ 1,058	$ 1,088
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Delayed Draw), Due 11/3/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SportsOperatingHoldingsIiLlcMember	mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.85%	5.75%
Interest Rate		11.17%	10.17%
Acquisition Date		Nov. 03, 2022	Nov. 03, 2022
Maturity		Nov. 03, 2027	Nov. 03, 2027
Principal		$ 2,399	$ 2,400
Fair Value		$ 243
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Revolver), Due, 11/3/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SportsOperatingHoldingsIiLlcMember	mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Retail	Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.85%	5.75%
Interest Rate		11.17%	10.17%
Acquisition Date		Nov. 03, 2022	Nov. 03, 2022
Maturity		Nov. 03, 2027	Nov. 03, 2027
Principal		$ 519	$ 519
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC, Due, 11/3/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SportsOperatingHoldingsIiLlcMember	mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.85%	5.75%
Interest Rate		11.17%	10.17%
Acquisition Date		Nov. 03, 2022	Nov. 03, 2022
Maturity		Nov. 03, 2027	Nov. 03, 2027
Principal		$ 2,970	$ 2,993
Fair Value		$ 2,985	$ 2,918
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, ( Revolver), Senior Secured Loans, due 1/12/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember	mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.85%	6.75%
Interest Rate		12.24%	11.14%
Acquisition Date		Jan. 12, 2021	Jan. 12, 2021
Maturity		Jan. 12, 2027	Jan. 12, 2027
Principal		$ 323	$ 322
Fair Value		$ 189	$ 79
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, One, due 1/12/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember	mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.85%	6.75%
Interest Rate		12.24%	11.48%
Acquisition Date		Jan. 12, 2021	Jan. 12, 2021
Maturity		Jan. 12, 2027	Jan. 12, 2027
Principal		$ 2,000	$ 2,000
Fair Value		$ 1,988	$ 1,968
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Three, due 1/12/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.85%
Interest Rate		12.24%
Acquisition Date		May 31, 2023
Maturity		Jan. 12, 2027
Principal		$ 256
Fair Value		$ 255
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Two, due 1/12/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:StarComplianceMidCoLLCMember	mrcc:StarComplianceMidCoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Banking	Banking
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.85%	6.75%
Interest Rate		12.24%	11.48%
Acquisition Date		Oct. 12, 2021	Oct. 12, 2021
Maturity		Jan. 12, 2027	Jan. 12, 2027
Principal		$ 335	$ 336
Fair Value		$ 333	$ 330
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T A T T Buyer, L L C, Senior Secured Loans, due 3/30/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, One, due 4/17/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TCFIIIOWLBuyerLLCMember	mrcc:TCFIIIOWLBuyerLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building	Construction & Building
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.61%	5.50%
Interest Rate		10.93%	9.94%
Acquisition Date		Apr. 19, 2021	Apr. 19, 2021
Maturity		Apr. 17, 2026	Apr. 17, 2026
Principal		$ 2,004	$ 2,019
Fair Value		$ 2,004	$ 2,022
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Three, due 4/17/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TCFIIIOWLBuyerLLCMember	mrcc:TCFIIIOWLBuyerLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building	Construction & Building
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.61%	5.50%
Interest Rate		10.93%	9.94%
Acquisition Date		Dec. 17, 2021	Dec. 17, 2021
Maturity		Apr. 17, 2026	Apr. 17, 2026
Principal		$ 2,196	$ 2,213
Fair Value		$ 2,196	$ 2,215
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Two, due 4/17/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TCFIIIOWLBuyerLLCMember	mrcc:TCFIIIOWLBuyerLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building	Construction & Building
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.61%	5.50%
Interest Rate		10.93%	9.94%
Acquisition Date		Apr. 19, 2021	Apr. 19, 2021
Maturity		Apr. 17, 2026	Apr. 17, 2026
Principal		$ 2,447	$ 2,466
Fair Value		$ 2,447	$ 2,469
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T E A M Public Choices, L L C, Senior Secured Loans, due 12/17/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T G G T S Acquisition Company, Senior Secured Loans, due 12/12/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J C Spartech Acquisition Corp., Senior Secured Loans, due 5/5/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J Management Hold Co L L C ( Revolver), Senior Secured Loans, Due 6/28/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	Beverage, Food & Tobacco
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.61%	5.50%
Interest Rate		10.93%	9.89%
Acquisition Date		Sep. 09, 2020	Sep. 09, 2020
Maturity		Jun. 28, 2024	Jun. 28, 2024
Principal		$ 477	$ 477
Fair Value		$ 80	$ 80	80
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: T J Management Hold Co L L C, Equity Securities, Common stock
Investments
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments	Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]	T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Acquisition Date		Sep. 09, 2020	Sep. 09, 2020
Principal		$ 0
Fair Value		$ 3,183	$ 2,766	$ 2,741	$ 3,148
Investment, Non-income Producing [true false]		true	false
Number of shares held		16		16
Investment, Identifier [Axis]: TJ Management HoldCo LLC, Equity Securities, due 9/9/2020
Investments
Number of shares held			16
Investment, Identifier [Axis]: Tait L L C ( Revolver), Senior Secured Loans, due 3/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Tait L L C, Senior Secured Loans, due 3/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Teneo Holdings L L C, Senior Secured Loans, due 7/11/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Cook & Boardman Group L L C, Senior Secured Loans, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kleinfelder Group, Inc., Senior Secured Loans, due 11/29/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kyjen Company, L L C ( Revolver), Senior Secured Loans, due 4/3/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TheKyjenCompanyLLCMember	mrcc:TheKyjenCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.75%	7.10%
Interest Rate, Paid in Cash		12.21%
Interest Rate, Paid in Kind		1%	0.50%
Acquisition Date		May 14, 2021	May 14, 2021
Maturity		Apr. 03, 2026	Apr. 03, 2026
Principal		$ 105	$ 105
Fair Value			$ 88
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior SEcured Loans, Two, Due 4/3/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TheKyjenCompanyLLCMember	mrcc:TheKyjenCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.50%	7%
Interest Rate, Paid in Cash			10.92%
Interest Rate, Paid in Kind		12.96%	11.42%
Acquisition Date		Sep. 13, 2022	Sep. 13, 2022
Maturity		Apr. 03, 2026	Apr. 03, 2026
Principal		$ 1
Fair Value		$ 1
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior Secured Loans, due 4/3/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TheKyjenCompanyLLCMember	mrcc:TheKyjenCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.75%	7.15%
Interest Rate, Paid in Cash		12.21%	11.15%
Interest Rate, Paid in Kind		1%	0.50%
Acquisition Date		May 14, 2021	May 14, 2021
Maturity		Apr. 03, 2026	Apr. 03, 2026
Principal		$ 988	$ 986
Fair Value		$ 979	$ 975
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Thrasio, L L C, Senior Secured Loans, due 12/18/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ThrasioLLCMember	mrcc:ThrasioLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.26%	7%
Interest Rate		12.65%	11.73%
Acquisition Date		Dec. 18, 2020	Dec. 18, 2020
Maturity		Dec. 18, 2026	Dec. 18, 2026
Principal		$ 2,433	$ 2,445
Fair Value		$ 2,043	$ 2,445
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Delayed Draw), Senior Secured Loans, due 2/16/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TigerConnectIncMember	mrcc:TigerConnectIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.75%	7.25%
Interest Rate		12.27%
Interest Rate, Paid in Kind			3.63%
Acquisition Date		Feb. 16, 2022	Feb. 16, 2022
Maturity		Feb. 16, 2028	Feb. 16, 2028
Principal		$ 225	$ 124
Fair Value		$ 106	$ 27
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Revolver), Senior Secured Loans, due 2/16/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TigerConnectIncMember	mrcc:TigerConnectIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.75%	7.25%
Interest Rate		12.27%	11.49%
Acquisition Date		Feb. 16, 2022	Feb. 16, 2022
Maturity		Feb. 16, 2028	Feb. 16, 2028
Principal		$ 429	$ 429
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Tiger Connect, Inc., Senior Secured Loans, due 2/16/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TigerConnectIncMember	mrcc:TigerConnectIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.75%	7.25%
Interest Rate		12.27%
Interest Rate, Paid in Cash			7.86%
Interest Rate, Paid in Kind			3.63%
Acquisition Date		Feb. 16, 2022	Feb. 16, 2022
Maturity		Feb. 16, 2028	Feb. 16, 2028
Principal		$ 3,000	$ 3,000
Fair Value		$ 2,940	$ 2,963
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Trident Maritime Systems, Inc ( Revolver), Senior Secured Loans, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, One, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, Two, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, One, due 12/14/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, Two, due 12/14/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck-Lite Co., LLC, Senior Secured Loans, Three, due 12/14/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: V B E1, L L C ( Delayed Draw), Unitranche Secured Loans, due 11/18/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VBE1LLCMember
Investment, Type [Extensible Enumeration]		Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]		Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.75%
Interest Rate		13.14%
Acquisition Date		Nov. 18, 2020
Maturity		Nov. 18, 2026
Principal		$ 2,250
Fair Value		$ 2,250
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: V B E1, L L C, Unitranche Secured Loans, due 11/18/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VBE1LLCMember
Investment, Type [Extensible Enumeration]			Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]			Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.65%
Interest Rate			12.38%
Acquisition Date			Nov. 18, 2020
Maturity			Nov. 18, 2026
Principal			$ 2,250
Fair Value			$ 2,257
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: V P S Holdings, L L C ( Revolver), Senior Secured Loans, due 10/4/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VPSHoldingsLLCMember	mrcc:VPSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.11%	9%
Interest Rate		12.43%
Interest Rate, Paid in Cash			11.39%
Interest Rate, Paid in Kind			2%
Acquisition Date		Oct. 05, 2018	Oct. 05, 2018
Maturity		Oct. 04, 2024	Oct. 04, 2024
Principal		$ 1,003	$ 1,002
Fair Value		$ 703	$ 102
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, One, due 10/4/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VPSHoldingsLLCMember	mrcc:VPSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.11%	9%
Interest Rate		12.43%
Interest Rate, Paid in Cash			11.39%
Interest Rate, Paid in Kind			2%
Acquisition Date		Oct. 05, 2018	Oct. 05, 2018
Maturity		Oct. 04, 2024	Oct. 04, 2024
Principal		$ 2,565	$ 3,246
Fair Value		$ 2,570	$ 3,252
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, Two, due 10/4/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VPSHoldingsLLCMember	mrcc:VPSHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.11%	9%
Interest Rate		12.43%
Interest Rate, Paid in Cash			11.39%
Interest Rate, Paid in Kind			2%
Acquisition Date		Oct. 05, 2018	Oct. 05, 2018
Maturity		Oct. 04, 2024	Oct. 04, 2024
Principal		$ 2,107	$ 2,656
Fair Value		$ 2,112	$ 2,661
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: V10 Entertainment, Inc, Equity Securities, Common Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		V10 Entertainment, Inc. [Member]
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jan. 12, 2023
Fair Value		$ 185
Investment, Non-income Producing [true false]		true
Number of shares held		392,157
Investment, Identifier [Axis]: V10 Entertainment, Inc. (Revolver), Senior Secured Loans, Due 1/12/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		V10 Entertainment, Inc. [Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Retail
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.10%
Interest Rate		12.35%
Acquisition Date		Jan. 12, 2023
Maturity		Jan. 12, 2028
Principal		$ 458
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: V10 Entertainment, Inc., Senior Secured Loans, Due 1/12/2028
Investments
Investment, Issuer Name [Extensible Enumeration]		V10 Entertainment, Inc. [Member]
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Retail
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.10%
Interest Rate		12.35%
Acquisition Date		Jan. 12, 2023
Maturity		Jan. 12, 2028
Principal		$ 3,990
Fair Value		$ 4,016
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products L L C ( Revolver), Senior Secured Loans, due 6/19/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			9.50%
Interest Rate			13.89%
Acquisition Date			Jun. 18, 2018
Maturity			Jun. 19, 2023
Principal			$ 1,095
Fair Value			$ 55
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products L L C , Equity Securities, Class A-1 units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember	mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber	Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		10%	10%
Acquisition Date		Jun. 18, 2018	Jun. 18, 2018
Fair Value		$ 402	$ 555
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, One, due 6/19/2023,
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.50%
Interest Rate, Paid in Cash			10.39%
Interest Rate, Paid in Kind			1.50%
Acquisition Date			Jun. 18, 2018
Maturity			Jun. 19, 2023
Principal			$ 1,609
Fair Value			$ 1,958
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Three, due 6/19/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.50%
Interest Rate, Paid in Kind			11.89%
Acquisition Date			Dec. 22, 2021
Maturity			Jun. 19, 2023
Principal			$ 502
Fair Value			$ 1,565
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Two, due 6/19/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.50%
Interest Rate			11.89%
Acquisition Date			Jun. 18, 2018
Maturity			Jun. 19, 2023
Principal			$ 260
Fair Value			$ 312
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Valudor Products LLC (Revolver), Senior Secured Loans, due 9/15/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.61%
Interest Rate		12.93%
Acquisition Date		Jun. 18, 2018
Maturity		Dec. 29, 2023
Principal		$ 1,095
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, One, due 9/15/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.61%
Interest Rate, Paid in Cash		11.43%
Interest Rate, Paid in Kind		1.50%
Acquisition Date		Jun. 18, 2018
Maturity		Dec. 29, 2023
Principal		$ 1,628
Fair Value		$ 1,895
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Three, due 9/15/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.61%
Interest Rate		12.93%
Acquisition Date		Dec. 22, 2021
Maturity		Dec. 29, 2023
Principal		$ 502
Fair Value		$ 1,423
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Two, due 9/15/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ValudorProductsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.50%
Interest Rate, Paid in Cash		1%
Interest Rate, Paid in Kind		12.93%
Acquisition Date		Jun. 18, 2018
Maturity		Dec. 29, 2023
Principal		$ 286
Fair Value		$ 276
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Delayed Draw), Senior Secured Loans, due 6/8/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VhagarPurchaserLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7%
Interest Rate		12.37%
Acquisition Date		Jun. 09, 2023
Maturity		Jun. 08, 2029
Principal		$ 667
Fair Value		$ 150
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Revolver), Senior Secured Loans, due, 6/8/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VhagarPurchaserLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7%
Interest Rate		12.24%
Acquisition Date		Jun. 09, 2023
Maturity		Jun. 08, 2029
Principal		$ 333
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vhagar Purchaser, LLC, Senior Secured Loans, due 6/8/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:VhagarPurchaserLlcMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7%
Interest Rate		12.24%
Acquisition Date		Jun. 09, 2023
Maturity		Jun. 08, 2029
Principal		$ 3,000
Fair Value		$ 3,000
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Equity Securities, Class A Units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Jul. 31, 2023
Fair Value		$ 1,342
Investment, Non-income Producing [true false]		true
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Five, due 1/31/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.26%
Interest Rate		13.63%
Acquisition Date		Jul. 31, 2023
Maturity		Jan. 31, 2028
Principal		$ 511
Fair Value		$ 463
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Four, No Maturity Date
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 02, 2019
Principal		$ 76
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, One, No Maturity Date
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 02, 2019
Principal		$ 637
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Three, No Maturity Date
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		May 02, 2019
Principal		$ 200
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Two, No Maturity Date
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Acquisition Date		Nov. 04, 2019
Principal		$ 122
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, One, due 1/31/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.26%
Interest Rate		13.63%
Acquisition Date		Jul. 31, 2023
Maturity		Jan. 31, 2028
Principal		$ 196
Fair Value		$ 196
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Three, due 1/31/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.26%
Interest Rate		13.63%
Acquisition Date		Jul. 31, 2023
Maturity		Jan. 31, 2028
Principal		$ 648
Fair Value		$ 648
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Two, due 12/12/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.26%
Interest Rate		13.66%
Acquisition Date		Sep. 08, 2023
Maturity		Dec. 12, 2028
Principal		$ 114
Fair Value		$ 114
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Four, due 5/12/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			12%
Interest Rate, Paid in Cash			4.25%
Interest Rate, Paid in Kind			12%
Acquisition Date			May 02, 2019
Maturity			May 12, 2023
Principal			$ 200
Fair Value			$ 196
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, One, due 5/12/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			12%
Interest Rate, Paid in Cash			4.51%
Interest Rate, Paid in Kind			12%
Acquisition Date			May 02, 2019
Maturity			May 12, 2023
Principal			$ 1,691
Fair Value			$ 1,657
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Three, due 5/12/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			12%
Interest Rate, Paid in Cash			4.42%
Interest Rate, Paid in Kind			12%
Acquisition Date			May 02, 2019
Maturity			May 12, 2023
Principal			$ 531
Fair Value			$ 520
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Two, due 5/12/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Broadcasting & Subscription
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			12%
Interest Rate, Paid in Cash			4.51%
Interest Rate, Paid in Kind			12%
Acquisition Date			Nov. 04, 2019
Maturity			May 12, 2023
Principal			$ 325
Fair Value			$ 318
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Four, due 2/6/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate, Paid in Kind			2%
Acquisition Date			Dec. 26, 2014
Maturity			Feb. 06, 2024
Principal			$ 1,149
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, One, due 2/6/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate, Paid in Kind			2%
Acquisition Date			Jul. 06, 2018
Maturity			Feb. 06, 2024
Principal			$ 7,026
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Three, due 2/6/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate, Paid in Kind			2%
Acquisition Date			Dec. 26, 2014
Maturity			Feb. 06, 2024
Principal			$ 13,552
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Two, due 2/6/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VinciBrandsLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Non-Durable
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate, Paid in Kind			2%
Acquisition Date			Mar. 09, 2018
Maturity			Feb. 06, 2024
Principal			$ 3,065
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: W3 Monroe R E Debt L L C, Senior Secured Loans, due 2/4/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:W3MonroeREDebtLLCMember	mrcc:W3MonroeREDebtLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember	mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate			10%
Interest Rate, Paid in Kind		10%
Acquisition Date		Feb. 05, 2021	Feb. 05, 2021
Maturity		Feb. 04, 2028	Feb. 04, 2028
Principal		$ 3,456	$ 3,210
Fair Value		$ 3,437	$ 3,210
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: W3 Monroe RE Debt LLC (Delayed Draw), Senior Secured Loans, Due 2/4/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:W3MonroeREDebtLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		mrcc:FireFinanceMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate, Paid in Kind		10%
Acquisition Date		Mar. 31, 2023
Maturity		Feb. 04, 2028
Principal		$ 134
Fair Value		$ 80
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Wheel Pros, Inc., Senior Secured Loans, due 5/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Delayed Draw), Senior Secured Loans, due 6/2/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.75%
Interest Rate			11.17%
Acquisition Date			Jun. 03, 2022
Maturity			Jun. 02, 2028
Principal			$ 1,406
Fair Value			$ 56
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Revolver), Senior Secured Loans, due 6/2/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WhistlerParentHoldingsIIIIncMember	mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.90%	6.75%
Interest Rate			11.17%
Interest Rate, Paid in Cash		9.52%
Interest Rate, Paid in Kind		4.75%
Acquisition Date		Jun. 03, 2022	Jun. 03, 2022
Maturity		Jun. 02, 2028	Jun. 02, 2028
Principal		$ 563	$ 563
Fair Value		$ 557	$ 84
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc., Senior Secured Loans, due 6/2/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WhistlerParentHoldingsIIIIncMember	mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		8.90%	6.75%
Interest Rate			11.17%
Interest Rate, Paid in Cash		9.52%
Interest Rate, Paid in Kind		4.75%
Acquisition Date		Jun. 03, 2022	Jun. 03, 2022
Maturity		Jun. 02, 2028	Jun. 02, 2028
Principal		$ 4,500	$ 4,500
Fair Value		$ 4,457	$ 4,457
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Whistler Parent Holdings III Inc. One Senior Secured Loans due 6/2/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		8.90%
Interest Rate, Paid in Cash		9.52%
Interest Rate, Paid in Kind		4.75%
Acquisition Date		Jun. 03, 2022
Maturity		Jun. 02, 2028
Principal		$ 56
Fair Value		$ 56
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: WillowTree, LLC, Unitranche Secured Loans, due 10/9/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WillowTreeLLCMember
Investment, Type [Extensible Enumeration]			Unitranche Debt [Member]
Investment, Industry Sector [Extensible Enumeration]			High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5%
Interest Rate			9.39%
Acquisition Date			Oct. 09, 2018
Maturity			Oct. 09, 2023
Principal			$ 7,326
Fair Value			$ 7,326
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C ( Delayed Draw), Junior Secured Loans, due 7/2/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember	mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]	Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Cash		8%	8%
Interest Rate, Paid in Kind		4%	4%
Acquisition Date		Sep. 25, 2023	Jul. 02, 2021
Maturity		Jul. 22, 2026	Jul. 02, 2026
Principal		$ 2,141	$ 6,708
Fair Value		$ 603	$ 6,014
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Equity Securities, Preferred units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember	mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Cash		8%	8%
Interest Rate, Paid in Kind		4%	4%
Acquisition Date		Jul. 02, 2021	Jul. 02, 2021
Fair Value		$ 1,806	$ 1,047
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, One, due 7/2/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate, Paid in Cash		8%
Interest Rate, Paid in Kind		4%
Acquisition Date		Jul. 02, 2021
Maturity		Jul. 02, 2026
Principal		$ 6,832
Fair Value		$ 6,716
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, Two, due 7/2/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WitkoffMonroe700JVLLCMember
Investment, Type [Extensible Enumeration]		Junior Loans [Member]
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate, Paid in Cash		8%
Interest Rate, Paid in Kind		4%
Acquisition Date		May 16, 2023
Maturity		Jul. 02, 2026
Principal		$ 1,182
Fair Value		$ 1,162
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc, Equity Securities, Class A units
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember	mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Equity Securities	Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Interest Rate, Paid in Kind		8%	8%
Acquisition Date		Jan. 28, 2020	Jan. 28, 2020
Fair Value		$ 243	$ 223
Investment, Non-income Producing [true false]		true	false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc. ( Revolver), Senior Secured Loans, due, 1/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember	mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6%	6.50%
Interest Rate		11.43%	10.94%
Acquisition Date		Jan. 28, 2020	Jan. 28, 2020
Maturity		Jan. 28, 2025	Jan. 28, 2025
Principal		$ 742	$ 742
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, One, due, 1/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember	mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing	Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6%	6.50%
Interest Rate		11.43%	10.94%
Acquisition Date		Jan. 28, 2020	Aug. 31, 2022
Maturity		Jan. 28, 2025	Jan. 28, 2025
Principal		$ 4,549	$ 1,822
Fair Value		$ 4,549	$ 1,829
Investment, Non-income Producing [true false]		false	false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, Two, due, 1/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6%
Interest Rate		11.43%
Acquisition Date		Aug. 31, 2022
Maturity		Jan. 28, 2025
Principal		$ 1,808
Fair Value		$ 1,812
Investment, Non-income Producing [true false]		false
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, due, 1/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:XanEduPublishingIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			10.94%
Acquisition Date			Jan. 28, 2020
Maturity			Jan. 28, 2025
Principal			$ 4,584
Fair Value			$ 4,602
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: Y S W H 4, L L C (Revolver), Senior Secured Loans, Due 11/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:YSWH4LLCRevolverMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7%
Interest Rate			11.44%
Acquisition Date			Jul. 20, 2022
Maturity			Nov. 20, 2025
Principal			$ 5,250
Fair Value			$ 1,776
Investment, Non-income Producing [true false]			false
Investment, Identifier [Axis]: iCIMS, Inc., Senior Secured Loans, Due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments	Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IcimsIncMember	mrcc:IcimsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		7.25%	7.25%
Interest Rate		12.63%	11.52%
Acquisition Date		Oct. 24, 2022	Oct. 24, 2022
Maturity		Aug. 18, 2028	Aug. 18, 2028
Principal		$ 2,500	$ 2,500
Fair Value		$ 2,500	$ 2,456
Investment, Non-income Producing [true false]		false	false
International
Investments
Fair Value			$ 10,405
Automotive
Investments
Fair Value		$ 16,626	16,637
Banking
Investments
Fair Value		16,436	19,817
Beverage, Food & Tobacco
Investments
Fair Value		11,434	12,470
Capital Equipment
Investments
Fair Value		18,936	19,012
Chemicals, Plastics & Rubber
Investments
Fair Value		3,996	4,445
Construction & Building
Investments
Fair Value		8,800	6,706
Environmental Industries
Investments
Fair Value		5,895	6,558
Hotels, Gaming & Leisure
Investments
Fair Value		115	2,720
Media: Advertising, Printing & Publishing
Investments
Fair Value		20,497	19,777
Media: Broadcasting & Subscription
Investments
Fair Value		2,763	2,691
Media: Diversified & Production
Investments
Fair Value		41,435	36,164
Retail
Investments
Fair Value		1,985	9,306
Telecommunications
Investments
Fair Value		7,356	7,595
Wholesale
Investments
Fair Value		14,790	14,165
Aerospace & Defense
Investments
Fair Value		7,578	7,436
Senior Secured Loans
Investments
Fair Value		416,316	434,023
Equity Securities
Investments
Fair Value		27,726	28,682
Non-controlled/non-affiliate company investments
Investments
Fair Value		$ 400,117	418,913
Non-controlled/non-affiliate company investments | Senior Secured Loans
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Principal		$ 390,734	425,065
Fair Value		$ 350,695	365,806
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Automotive
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 20,072	20,441
Fair Value		$ 16,552	16,326
Non-controlled/non-affiliate company investments | Senior Secured Loans | Banking
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 11,014	10,773
Fair Value		$ 10,782	10,345
Non-controlled/non-affiliate company investments | Senior Secured Loans | Beverage, Food & Tobacco
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 9,341	9,782
Fair Value		$ 8,171	8,358
Non-controlled/non-affiliate company investments | Senior Secured Loans | Capital Equipment
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 20,338	20,572
Fair Value		$ 18,504	18,808
Non-controlled/non-affiliate company investments | Senior Secured Loans | Chemicals, Plastics & Rubber
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 3,511	3,466
Fair Value		$ 3,594	3,890
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Construction & Building
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 9,374	6,698
Fair Value		$ 8,662	6,706
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Consumer Goods: Durable
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 10,717	11,292
Fair Value		$ 8,671	9,236
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Consumer Goods: Non-Durable
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 3,527	3,536
Fair Value		$ 3,023	3,508
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Environmental Industries
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 5,463	7,608
Fair Value		$ 5,446	6,201
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | FIRE: Finance
Investments
Principal		$ 16,334	29,660
Fair Value		$ 14,653	23,495
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | FIRE: Real Estate
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 4,464	7,857
Fair Value		$ 3,954	6,926
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Healthcare & Pharmaceuticals
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 68,260	61,092
Fair Value		$ 59,270	46,159
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | High Tech Industries
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 31,998	42,877
Fair Value		$ 29,320	38,519
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Hotels, Gaming & Leisure
Investments
Principal			3,097
Fair Value			2,611
Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Advertising, Printing & Publishing
Investments
Principal		$ 20,941	20,507
Fair Value		$ 17,967	17,345
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Broadcasting & Subscription
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 958	2,747
Fair Value		$ 958	2,691
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Diversified & Production
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 46,624	43,230
Fair Value		$ 40,777	35,592
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Retail
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IcimsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 639	8,772
Fair Value		$ 600	8,522
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Services: Business
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 56,367	58,660
Fair Value		$ 52,498	52,627
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Services: Consumer
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 29,326	30,570
Fair Value		$ 27,455	28,507
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Telecommunications
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 5,686	5,998
Fair Value		$ 5,050	5,269
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Senior Secured Loans | Wholesale
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Principal		$ 15,780	15,830
Fair Value		$ 14,788	14,165
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Equity Securities
Investments
Fair Value		$ 14,807	16,131
Non-controlled/non-affiliate company investments | Equity Securities | Automotive
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Fair Value		$ 74	311
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Banking
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Fair Value			$ 2,809
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Beverage, Food & Tobacco
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Fair Value			$ 1,266
Non-controlled/non-affiliate company investments | Equity Securities | Capital Equipment
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 432	$ 204
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Chemicals, Plastics & Rubber
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 402	$ 555
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Equity Securities | Construction & Building
Investments
Fair Value		$ 138
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Consumer Goods: Durable
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 68	$ 102
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Environmental Industries
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 449	$ 357
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | FIRE: Finance
Investments
Investment, Industry Sector [Extensible Enumeration]			FIRE: Finance
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 384	$ 397
Non-controlled/non-affiliate company investments | Equity Securities | FIRE: Real Estate
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 1,806	$ 1,047
Investment, Non-income Producing [true false]		false
Non-controlled/non-affiliate company investments | Equity Securities | Healthcare & Pharmaceuticals
Investments
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 2,774	$ 2,303
Non-controlled/non-affiliate company investments | Equity Securities | High Tech Industries
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 1,625	$ 1,340
Non-controlled/non-affiliate company investments | Equity Securities | Hotels, Gaming & Leisure
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 115	$ 109
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Media: Advertising, Printing & Publishing
Investments
Fair Value		$ 2,530	$ 2,432
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Media: Broadcasting & Subscription
Investments
Fair Value		$ 1,342
Non-controlled/non-affiliate company investments | Equity Securities | Media: Diversified & Production
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 658	$ 572
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Retail
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 420	$ 784
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Services: Business
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 1,098	$ 921
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Services: Consumer
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 434	$ 553
Non-controlled/non-affiliate company investments | Equity Securities | Telecommunications
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Fair Value		$ 56	$ 69
Investment, Non-income Producing [true false]		true
Non-controlled/non-affiliate company investments | Equity Securities | Wholesale
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Fair Value		$ 2
Investment, Non-income Producing [true false]		true
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: 360 Holdco, Inc. ( Delayed Draw), Senior Secured Loans, due 8/2/2025
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ThreeSixty360HoldcoIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5%
Interest Rate			9.42%
Maturity			Aug. 02, 2025
Principal			$ 827
Fair Value			$ 252
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: 360 Holdco, Inc., Senior Secured Loans, Two, due 8/1/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ThreeSixty360HoldcoIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		5.60%
Interest Rate		10.92%
Maturity		Aug. 01, 2025
Principal		$ 823
Fair Value		$ 823
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: 360 Holdco, Inc., Senior Secured Loans, due 8/1/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ThreeSixty360HoldcoIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		5.60%
Interest Rate		10.92%
Maturity		Aug. 01, 2025
Principal		$ 2,130
Fair Value		$ 2,130
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: 360 Holdco, Inc., Senior Secured Loans, due 8/2/2025
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ThreeSixty360HoldcoIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5%
Interest Rate			9.42%
Maturity			Aug. 02, 2025
Principal			$ 2,145
Fair Value			$ 2,145
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: A Q Carver Buyer, Inc., Senior Secured Loans, due 9/23/2025
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AQCarverBuyerIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5%
Interest Rate			9.38%
Maturity			Sep. 23, 2025
Principal			$ 4,838
Fair Value			$ 4,834
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Delayed Draw), Senior Secured Loans, due 12/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AccelerateAutoWorksIntermediateLLCMember	mrcc:AccelerateAutoWorksIntermediateLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.15%	4.50%
Interest Rate		10.57%	9.23%
Maturity		Dec. 01, 2027	Dec. 01, 2027
Principal		$ 388	$ 388
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Revolver), Senior Secured Loans, due 12/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AccelerateAutoWorksIntermediateLLCMember	mrcc:AccelerateAutoWorksIntermediateLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.15%	4.50%
Interest Rate		10.57%	9.23%
Maturity		Dec. 01, 2027	Dec. 01, 2027
Principal		$ 132	$ 132
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C, Senior Secured Loans, due 12/1/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AccelerateAutoWorksIntermediateLLCMember	mrcc:AccelerateAutoWorksIntermediateLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.15%	4.50%
Interest Rate		10.57%	9.23%
Maturity		Dec. 01, 2027	Dec. 01, 2027
Principal		$ 1,358	$ 1,391
Fair Value		$ 1,344	$ 1,386
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Analogic Corporation, Senior Secured Loans, due 6/24/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AnalogicCorporationMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.25%
Interest Rate			9.66%
Maturity			Jun. 24, 2024
Principal			$ 4,703
Fair Value			$ 4,433
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Avison Young ( U S A) Inc., Senior Secured Loans, due 1/30/2026
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:AvisonYoungUSAIncMember	mrcc:AvisonYoungUSAIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Real Estate	FIRE: Real Estate
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		International	International
Spread		6.76%	5.75%
Interest Rate		12.15%	10.19%
Maturity		Jan. 30, 2026	Jan. 30, 2026
Principal		$ 4,775	$ 4,800
Fair Value		$ 1,892	$ 4,020
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, One, due 11/5/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BromfordIndustriesLimitedMember	mrcc:BromfordIndustriesLimitedMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Aerospace & Defense	Aerospace & Defense
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]		International	International
Spread		5.25%	5.25%
Interest Rate		13.75%	12.75%
Maturity		Nov. 05, 2025	Nov. 05, 2025
Principal		$ 2,744	$ 2,744
Fair Value		$ 971	$ 2,581
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, Two, due 11/5/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:BromfordIndustriesLimitedMember	mrcc:BromfordIndustriesLimitedMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Aerospace & Defense	Aerospace & Defense
Investment, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember	us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]		International	International
Spread		5.25%	5.25%
Interest Rate		13.75%	12.75%
Maturity		Nov. 05, 2025	Nov. 05, 2025
Principal		$ 1,829	$ 1,829
Fair Value		$ 648	$ 1,720
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, One, due 4/10/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CHAHoldingsIncMember	mrcc:CHAHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.76%	4.50%
Interest Rate		10.15%	9.23%
Maturity		Apr. 10, 2025	Apr. 10, 2025
Principal		$ 1,944	$ 1,960
Fair Value		$ 1,913	$ 1,886
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, Two, due 4/10/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CHAHoldingsIncMember	mrcc:CHAHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.76%	4.50%
Interest Rate		10.15%	9.23%
Maturity		Apr. 10, 2025	Apr. 10, 2025
Principal		$ 410	$ 413
Fair Value		$ 403	$ 398
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: CBC Restaurant Corp. Senior Secured Loans
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CBCRestaurantCorpMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Interest Rate, Paid in Kind			5%
Principal			$ 1,066
Fair Value			$ 415
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Cadent, L L C ( Revolver), Senior Secured Loans, due 9/11/2025
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CadentLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			11.23%
Maturity			Sep. 11, 2025
Principal			$ 167
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Cadent, L L C, Senior Secured Loans, due 9/11/2025
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CadentLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Media: Advertising, Printing & Publishing
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.50%
Interest Rate			11.23%
Maturity			Sep. 11, 2025
Principal			$ 4,237
Fair Value			$ 4,131
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Cano Health, L L C, Senior Secured Loans, due 11/23/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CanoHealthLLMember	mrcc:CanoHealthLLMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.10%	4%
Interest Rate		9.42%	8.42%
Maturity		Nov. 23, 2027	Nov. 23, 2027
Principal		$ 1,955	$ 1,970
Fair Value		$ 1,272	$ 1,572
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Corel Inc., Senior Secured Loans, due 7/2/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:CorelIncMember	mrcc:CorelIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		International	country:US
Spread		5.10%	5%
Interest Rate		10.52%	9.73%
Maturity		Jul. 02, 2026	Jul. 02, 2026
Principal		$ 3,450	$ 3,600
Fair Value		$ 3,324	$ 3,365
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: D S Parent, Inc., Senior Secured Loans, due 12/8/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DSParentIncMember	mrcc:DSParentIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.75%	5.75%
Interest Rate		11.34%	9.92%
Maturity		Dec. 08, 2028	Dec. 08, 2028
Principal		$ 2,738	$ 2,850
Fair Value		$ 2,714	$ 2,725
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, One, due 10/1/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DresserUtilitySolutionsLLCfkaNGSUSFincoLLCMember	mrcc:DresserUtilitySolutionsLLCfkaNGSUSFincoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Utilities: Oil & Gas	Utilities: Oil & Gas
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.10%	4.25%
Interest Rate		9.42%	8.63%
Maturity		Oct. 01, 2025	Oct. 01, 2025
Principal		$ 1,664	$ 1,678
Fair Value		$ 1,631	$ 1,619
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, Two, due 10/1/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DresserUtilitySolutionsLLCfkaNGSUSFincoLLCMember	mrcc:DresserUtilitySolutionsLLCfkaNGSUSFincoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Utilities: Oil & Gas	Utilities: Oil & Gas
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.35%	5.25%
Interest Rate		10.67%	9.63%
Maturity		Oct. 01, 2025	Oct. 01, 2025
Principal		$ 243	$ 245
Fair Value		$ 239	$ 239
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Drilling Info Holdings, Inc., Senior Secured Loans, due 7/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:DrillingInfoHoldingsIncMember	mrcc:DrillingInfoHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		us-gaap:EnergySectorMember	Utilities: Oil & Gas
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.35%	4.25%
Interest Rate		9.67%	8.63%
Maturity		Jul. 30, 2025	Jul. 30, 2025
Principal		$ 4,434	$ 4,469
Fair Value		$ 4,299	$ 4,313
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Elevate Textiles, Inc. (fka International Textile Group, Inc.), Senior Secured Loans, due 9/30/2027
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ElevateTextilesIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		6.65%
Interest Rate		11.89%
Maturity		Sep. 30, 2027
Principal		$ 800
Fair Value		$ 800
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Elevate Textiles, Inc. (fka International Textile Group, Inc., Equity Securities, Common Units
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ElevateTextilesIncMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Fair Value		$ 75
Investment, Non-income Producing [true false]		true
Number of shares held		25,524
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Eliassen Group, L L C ( Delayed Draw), Senior Secured Loans, due 4/14/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EliassenGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.50%	5.50%
Interest Rate		10.82%
Interest Rate, Paid in Cash			8.88%
Maturity		Apr. 14, 2028	Apr. 14, 2028
Principal		$ 740	$ 740
Fair Value		$ 228	$ 109
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Eliassen Group, L L C, Senior Secured Loans, due 4/14/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:EliassenGroupLLCMember	mrcc:EliassenGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.50%	5.50%
Interest Rate		10.84%	10.08%
Maturity		Apr. 14, 2028	Apr. 14, 2028
Principal		$ 3,227	$ 3,251
Fair Value		$ 3,173	$ 3,194
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Engage2 Excel, Inc. ( Revolver), Senior Secured Loans, due 3/7/2023
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:Engage2ExcelIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.25%
Interest Rate, Paid in Kind			13.75%
Maturity			Mar. 07, 2023
Principal			$ 554
Fair Value			$ 509
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Engage2 Excel, Inc. (Revolver), Senior Secured Loans, One, due 12/31/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Engage2ExcelIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.35%
Interest Rate		12.69%
Maturity		Dec. 31, 2023
Principal		$ 550
Fair Value		$ 550
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, One, due 12/31/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Engage2ExcelIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.35%
Interest Rate		12.21%
Maturity		Dec. 31, 2023
Principal		$ 4,282
Fair Value		$ 4,270
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, One, due 3/7/2023
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:Engage2ExcelIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.25%
Interest Rate, Paid in Kind			11.98%
Maturity			Mar. 07, 2023
Principal			$ 4,283
Fair Value			$ 4,242
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, Two, due 12/31/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Engage2ExcelIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.35%
Interest Rate		12.21%
Maturity		Dec. 31, 2023
Principal		$ 773
Fair Value		$ 771
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, Two,due 3/7/2023
Investments
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7.25%
Interest Rate, Paid in Cash			11.98%
Maturity			Mar. 07, 2023
Principal			$ 773
Fair Value			$ 766
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Excel Fitness Holdings, Inc. ( Revolver), Senior Secured Loans, due 4/28/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExcelFitnessHoldingsIncMember	mrcc:ExcelFitnessHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Hotels, Gaming & Leisure	Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.40%	5.25%
Interest Rate		10.79%	9.67%
Maturity		Apr. 28, 2028	Apr. 28, 2028
Principal		$ 625	$ 625
Fair Value			$ 306
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Excel Fitness Holdings, Inc., Senior Secured Loans, due 4/27/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ExcelFitnessHoldingsIncMember	mrcc:ExcelFitnessHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Hotels, Gaming & Leisure	Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.40%	5.25%
Interest Rate		10.79%	10.29%
Maturity		Apr. 27, 2029	Apr. 27, 2029
Principal		$ 4,331	$ 4,364
Fair Value		$ 4,108	$ 4,102
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: H A H Group Holding Company L L C, Senior Secured Loans, due 10/29/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HAHGroupHoldingCompanyLLCMember	mrcc:HAHGroupHoldingCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5%	5%
Interest Rate		10.42%	9.43%
Maturity		Oct. 29, 2027	Oct. 29, 2027
Principal		$ 2,958	$ 2,978
Fair Value		$ 2,928	$ 2,847
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: H A L O Buyer, Inc., Senior Secured Loans, due 6/30/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HALOBuyerIncMember	mrcc:BMCAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Wholesale	Wholesale
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.60%	4.50%
Interest Rate		9.92%	8.88%
Maturity		Jun. 30, 2025	Jun. 30, 2025
Principal		$ 4,736	$ 4,774
Fair Value		$ 3,658	$ 4,219
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, One, due 12/13/2024
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HarbourBenefitHoldingsIncMember	mrcc:HarbourBenefitHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.15%	5.25%
Interest Rate		10.54%	9.98%
Maturity		Dec. 13, 2024	Dec. 13, 2024
Principal		$ 2,865	$ 2,901
Fair Value		$ 2,865	$ 2,898
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, Two, due 12/13/2024
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HarbourBenefitHoldingsIncMember	mrcc:HarbourBenefitHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.10%	5.25%
Interest Rate		10.42%	9.63%
Maturity		Dec. 13, 2024	Dec. 13, 2024
Principal		$ 61	$ 61
Fair Value		$ 61	$ 61
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Intermedia Holdings, Inc., Senior Secured Loans, due 7/21/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:IntermediaHoldingsIncMember	mrcc:IntermediaHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.11%	6%
Interest Rate		11.43%	10.38%
Maturity		Jul. 21, 2025	Jul. 21, 2025
Principal		$ 1,746	$ 1,760
Fair Value		$ 1,665	$ 1,360
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: International Textile Group, Inc., Senior Secured Loans, due 5/1/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:InternationalTextileGroupIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Consumer Goods: Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5%
Interest Rate			9.21%
Maturity			May 01, 2024
Principal			$ 1,664
Fair Value			$ 1,166
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Keystone Purchaser, L L C, Senior Secured Loans, due 5/7/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:KeystonePurchaserLLCMember	mrcc:KeystonePurchaserLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Transportation: Cargo	Transportation: Cargo
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.75%	5.50%
Interest Rate		10.96%	10.60%
Maturity		May 07, 2027	May 07, 2027
Principal		$ 4,917	$ 4,955
Fair Value		$ 4,880	$ 4,955
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: L S C S Holdings, Inc., Senior Secured Loans, due 12/15/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LSCSHoldingsIncMember	mrcc:LSCSHoldingsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.61%	4.50%
Interest Rate		9.93%	8.88%
Maturity		Dec. 15, 2028	Dec. 15, 2028
Principal		$ 1,814	$ 1,828
Fair Value		$ 1,792	$ 1,751
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Laseraway Intermediate Holdings I I, L L C, Senior Secured Loans, due 10/14/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LaserawayIntermediateHoldingsIILLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.75%	5.75%
Interest Rate		11.32%	9.76%
Maturity		Oct. 14, 2027	Oct. 14, 2027
Principal		$ 2,183	$ 2,200
Fair Value		$ 2,153	$ 2,161
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Lightbox Intermediate, L. P., Senior Secured Loans, due 5/11/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:LightboxIntermediateL.PMember	mrcc:LightboxIntermediateL.PMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.26%	5%
Interest Rate		10.65%	9.73%
Maturity		May 11, 2026	May 11, 2026
Principal		$ 4,788	$ 4,825
Fair Value		$ 4,644	$ 4,656
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Liqui- Box Holdings, Inc., Senior Secured Loans, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:Liqui-BoxHoldingsIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Containers, Packaging & Glass
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			4.50%
Interest Rate			9.23%
Maturity			Feb. 26, 2027
Principal			$ 4,225
Fair Value			$ 4,186
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Delayed Draw), Senior Secured Loans, due 1/7/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MacQueenEquipmentLLCMember	mrcc:MacQueenEquipmentLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.51%	5.25%
Interest Rate		10.90%	9.98%
Maturity		Jan. 07, 2028	Jan. 07, 2028
Principal		$ 591	$ 592
Fair Value		$ 78	$ 69
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Revolver), Senior Secured Loans, due 1/7/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MacQueenEquipmentLLCMember	mrcc:MacQueenEquipmentLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.51%	5.25%
Interest Rate		10.90%	9.98%
Maturity		Jan. 07, 2028	Jan. 07, 2028
Principal		$ 296	$ 296
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Mac Queen Equipment, L L C, Senior Secured Loans, due 1/7/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MacQueenEquipmentLLCMember	mrcc:MacQueenEquipmentLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Capital Equipment	Capital Equipment
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.51%	5.25%
Interest Rate		10.90%	9.98%
Maturity		Jan. 07, 2028	Jan. 07, 2028
Principal		$ 2,080	$ 2,096
Fair Value		$ 2,080	$ 2,096
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Mavenir Systems, Inc., Senior Secured Loans, due 8/18/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MavenirSystemsIncMember	mrcc:MavenirSystemsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.11%	4.75%
Interest Rate		10.49%	9.42%
Maturity		Aug. 18, 2028	Aug. 18, 2028
Principal		$ 1,642	$ 1,654
Fair Value		$ 1,310	$ 1,350
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Mc Kissock Investment Holdings, L L C, Senior Secured Loans, due 3/9/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:McKissockInvestmentHoldingsLLCMember	mrcc:LaserawayIntermediateHoldingsIILLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Consumer	Services: Consumer
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5%	5%
Interest Rate		10.43%	8.87%
Maturity		Mar. 09, 2029	Mar. 09, 2029
Principal		$ 2,463	$ 2,481
Fair Value		$ 2,435	$ 2,322
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Minotaur Acquisition, Inc., Senior Secured Loans, due 3/27/2026
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MinotaurAcquisitionIncMember	mrcc:MinotaurAcquisitionIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.85%	4.75%
Interest Rate		10.17%	9.17%
Maturity		Mar. 27, 2026	Mar. 27, 2026
Principal		$ 4,819	$ 4,857
Fair Value		$ 4,808	$ 4,656
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Natus Medical Incorporated, Senior Secured Loans, due 7/20/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NatusMedicalIncorporatedMember	mrcc:NatusMedicalIncorporatedMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.50%	5.50%
Interest Rate		11.04%	8.68%
Maturity		Jul. 20, 2029	Jul. 20, 2029
Principal		$ 4,962	$ 5,000
Fair Value		$ 4,665	$ 4,650
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: North Haven Spartan U S Holdco, L L C, Senior Secured Loans, due 6/6/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:NorthHavenSpartanUSHoldcoLLCMember	mrcc:NorthHavenSpartanUSHoldcoLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Hotels, Gaming & Leisure	Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.65%	10.71%
Maturity		Jun. 06, 2025	Jun. 06, 2025
Principal		$ 2,256	$ 2,280
Fair Value		$ 2,242	$ 2,202
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, One, due 6/22/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:OffenIncMember	mrcc:OffenIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		us-gaap:EnergySectorMember	Utilities: Oil & Gas
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.43%	5%
Interest Rate		10.46%	9.38%
Maturity		Jun. 22, 2026	Jun. 22, 2026
Principal		$ 2,249	$ 2,249
Fair Value		$ 2,249	$ 2,249
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, Two, due 6/22/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:OffenIncMember	mrcc:OffenIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		us-gaap:EnergySectorMember	Utilities: Oil & Gas
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.43%	5%
Interest Rate		10.46%	9.38%
Maturity		Jun. 22, 2026	Jun. 22, 2026
Principal		$ 861	$ 867
Fair Value		$ 861	$ 867
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, One, due 10/21/2024
Investments
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			4.50%
Interest Rate, Paid in Cash			9.23%
Maturity			Oct. 21, 2024
Principal			$ 2,406
Fair Value			$ 2,190
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Three, due 10/21/2024
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:OrbitPurchaserLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			4.50%
Interest Rate			9.23%
Maturity			Oct. 21, 2024
Principal			$ 543
Fair Value			$ 494
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Two, due 10/21/2024
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:Engage2ExcelIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			4.50%
Interest Rate, Paid in Kind			9.23%
Maturity			Oct. 21, 2024
Principal			$ 1,858
Fair Value			$ 1,691
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Output Services Group Inc. Senior Secured Loans Due 6/29/2026
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:OrbitPurchaserLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			6.75%
Interest Rate, Paid in Cash			9.80%
Interest Rate, Paid in Kind			1.50%
Maturity			Jun. 29, 2026
Principal			$ 4,807
Fair Value			$ 3,275
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Output Services Group, Inc., Senior Secured Loans, due 3/27/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:OutputServicesGroupIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		5.25%
Interest Rate, Paid in Cash		10.82%
Interest Rate, Paid in Kind		1.50%
Maturity		Jun. 29, 2026
Principal		$ 4,812
Fair Value		$ 1,011
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: P H Beauty Holdings I I I, I N C., Senior Secured Loans, due 9/26/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PHBeautyHoldingsIIIINCMember	mrcc:PHBeautyHoldingsIIIINCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Non-Durable	Consumer Goods: Non-Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5%	5%
Interest Rate		10.68%	9.73%
Interest Rate, Paid in Kind		0.75%
Maturity		Sep. 26, 2025	Sep. 26, 2025
Principal		$ 2,374	$ 2,393
Fair Value		$ 2,018	$ 1,950
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: P V H C Holding Corp, Senior Secured Loans, due 2/17/2027
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PVHCHoldingCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Containers, Packaging & Glass
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Interest Rate, Paid in Cash		11.04%
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: P V H C Holding Corp, Senior Secured Loans, due 8/5/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PVHCHoldingCorpMember	mrcc:PVHCHoldingCorpMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Containers, Packaging & Glass
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread		5.65%	4.75%
Interest Rate			9.48%
Maturity		Feb. 17, 2027	Aug. 05, 2024
Principal		$ 1,897	$ 3,184
Fair Value		$ 1,830	$ 3,072
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Paragon Healthcare Inc. Senior Secured Loan Due 1/19/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ParagonHealthcareIncMember	mrcc:ParagonHealthcareIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.85%	5.75%
Interest Rate		11.17%	9.81%
Maturity		Jan. 19, 2027	Jan. 19, 2027
Principal		$ 2,111	$ 2,127
Fair Value		$ 2,081	$ 2,109
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Paragon HealthcareInc. Delayed Draw Senior Secured Loans due 1/19/2027
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ParagonHealthcareIncMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]			Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.75%
Interest Rate			10.06%
Maturity			Jan. 19, 2027
Principal			$ 366
Fair Value			$ 242
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Paragon HealthcareInc. Revolver Senior Secured Loan Due 1/19/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ParagonHealthcareIncMember	mrcc:ParagonHealthcareIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.75%	5.75%
Interest Rate		11.12%	10.26%
Maturity		Jan. 19, 2027	Jan. 19, 2027
Principal		$ 490	$ 490
Fair Value			$ 61
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Paragon HealthcareInc., Senior Secured Loan, Two, Due 1/19/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ParagonHealthcareIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		5.75%
Interest Rate		11.12%
Maturity		Jan. 19, 2027
Principal		$ 364
Fair Value		$ 359
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group), Senior Secured Loan due 6/15/2023
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PhoenixChemicalHoldingCompanyLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			7%
Interest Rate			11.39%
Maturity			Jun. 15, 2023
Principal			$ 1,139
Fair Value			$ 1,132
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group), Senior Secured Loan due 8/2/2024
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PhoenixChemicalHoldingCompanyLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Spread		7.11%
Interest Rate		12.43%
Maturity		Aug. 02, 2024
Principal		$ 1,131
Fair Value		$ 1,030
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Polychem Acquisition, L L C, Senior Secured Loans, due 3/17/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PolychemAcquisitionLLCMember	mrcc:PolychemAcquisitionLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Containers, Packaging & Glass	Containers, Packaging & Glass
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.11%	5%
Interest Rate		10.43%	9.38%
Maturity		Mar. 17, 2025	Mar. 17, 2025
Principal		$ 2,865	$ 2,888
Fair Value		$ 2,865	$ 2,888
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Polyventive Lender Holding Company LLC, Equity Securities
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:PolyventiveLenderHoldingCompanyLlcMember
Investment, Type [Extensible Enumeration]		Equity Securities
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US
Percentage of equity interest		0.84%
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Radiology Partners, Inc., Senior Secured Loans, due 7/9/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RadiologyPartnersIncMember	mrcc:RadiologyPartnersIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Healthcare & Pharmaceuticals Sector [Member]	Healthcare & Pharmaceuticals Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.68%	4.25%
Interest Rate		10.18%	8.64%
Maturity		Jul. 09, 2025	Jul. 09, 2025
Principal		$ 4,750	$ 4,760
Fair Value		$ 3,599	$ 4,018
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Research Now Group, Inc. and Survey Sampling International, L L C, Senior Secured Loans, due 12/20/2024
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:ResearchNowGroupInc.andSurveySamplingInternationalLLCMember	mrcc:ResearchNowGroupInc.andSurveySamplingInternationalLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Diversified & Production
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.76%	5.50%
Interest Rate		11.13%	8.84%
Maturity		Dec. 20, 2024	Dec. 20, 2024
Principal		$ 6,597	$ 6,650
Fair Value		$ 4,823	$ 5,035
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Runner Buyer I N C., Senior Secured Loans, due 10/23/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:RunnerBuyerINCMember	mrcc:RunnerBuyerINCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Consumer Goods: Durable	Consumer Goods: Durable
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.61%	5.50%
Interest Rate		11.04%	10.23%
Maturity		Oct. 23, 2028	Oct. 23, 2028
Principal		$ 2,955	$ 2,978
Fair Value		$ 2,352	$ 2,114
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: S I R V A Worldwide Inc., Senior Secured Loans, due 8/4/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SIRVAWorldwideIncMember	mrcc:SecretariatAdvisorsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.61%	5.50%
Interest Rate		10.93%	10.23%
Maturity		Aug. 04, 2025	Aug. 04, 2025
Principal		$ 1,763	$ 1,800
Fair Value		$ 1,589	$ 1,606
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: S T A T S Intermediate Holdings, L L C, Senior Secured Loans, due 7/10/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:STATSIntermediateHoldingsLLCMember	mrcc:STATSIntermediateHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Diversified & Production
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.51%	5.25%
Interest Rate		10.89%	9.90%
Maturity		Jul. 10, 2026	Jul. 10, 2026
Principal		$ 4,813	$ 4,850
Fair Value		$ 4,548	$ 4,498
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: S W Ingredients Holdings, L L C, Senior Secured Loans, due 7/3/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SWIngredientsHoldingsLLCMember	mrcc:SWIngredientsHoldingsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Beverage, Food & Tobacco	mrcc:BeverageFoodAndTobaccoSectorMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.75%	4.75%
Interest Rate		10.17%	9.13%
Maturity		Jul. 03, 2025	Jul. 03, 2025
Principal		$ 3,553	$ 3,581
Fair Value		$ 3,551	$ 3,581
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Sandvine Corporation, Senior Secured Loans, due 10/31/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SandvineCorporationMember	mrcc:SandvineCorporationMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Telecommunications	Telecommunications
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.50%	4.50%
Interest Rate		9.82%	8.88%
Maturity		Oct. 31, 2025	Oct. 31, 2025
Principal		$ 1,973	$ 2,000
Fair Value		$ 1,699	$ 1,904
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Secretariat Advisors L L C, Senior Secured Loans, due 12/29/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecretariatAdvisorsLLCMember	mrcc:OutputServicesGroupIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.01%	4.75%
Interest Rate		10.40%	9.48%
Maturity		Dec. 29, 2028	Dec. 29, 2028
Principal		$ 1,680	$ 1,693
Fair Value		$ 1,663	$ 1,634
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Secretariat Advisors LLC, Senior Secured Loans, Two, due 12/29/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:SecretariatAdvisorsLLCMember	mrcc:SecretariatAdvisorsLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.01%	4.75%
Interest Rate		10.40%	9.48%
Maturity		Dec. 29, 2028	Dec. 29, 2028
Principal		$ 268	$ 270
Fair Value		$ 265	$ 260
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: T A T T Buyer, L L C, Senior Secured Loans, due 3/30/2029
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TATTBuyerLLCMember	mrcc:TheOctaveMusicGroupIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Media: Diversified & Production	Media: Diversified & Production
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5%	5%
Interest Rate		10.39%	8.98%
Maturity		Mar. 30, 2029	Mar. 30, 2029
Principal		$ 3,300	$ 3,325
Fair Value		$ 3,297	$ 3,242
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: T E A M Public Choices, L L C, Senior Secured Loans, due 12/17/2027
Investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TEAMPublicChoicesLLCMember	mrcc:TEAMPublicChoicesLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		FIRE: Finance	mrcc:FireFinanceMember
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.43%	5%
Interest Rate		10.88%	9.93%
Maturity		Dec. 17, 2027	Dec. 17, 2027
Principal		$ 2,932	$ 2,955
Fair Value		$ 2,890	$ 2,822
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: T G G T S Acquisition Company, Senior Secured Loans, due 12/12/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TGGTSAcquisitionCompanyMember	mrcc:TGGTSAcquisitionCompanyMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		High Tech Industries Sector [Member]	High Tech Industries Sector [Member]
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.61%	6.50%
Interest Rate		11.93%	10.88%
Maturity		Dec. 12, 2025	Dec. 12, 2025
Principal		$ 2,946	$ 3,190
Fair Value		$ 2,886	$ 3,143
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: T J C Spartech Acquisition Corp., Senior Secured Loans, due 5/5/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TJCSpartechAcquisitionCorpMember	mrcc:TJCSpartechAcquisitionCorpMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Chemicals, Plastics & Rubber	Chemicals, Plastics & Rubber
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.75%	4.75%
Interest Rate		10.05%	8.53%
Maturity		May 05, 2028	May 05, 2028
Principal		$ 4,221	$ 4,253
Fair Value		$ 3,799	$ 4,131
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Tait L L C ( Revolver), Senior Secured Loans, due 3/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TaitLLCMember	mrcc:TaitLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Hotels, Gaming & Leisure	Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	us-gaap:PrimeRateMember
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5%	4%
Interest Rate		10.25%	10.25%
Maturity		Mar. 28, 2025	Mar. 28, 2025
Principal		$ 769	$ 769
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Tait L L C, Senior Secured Loans, due 3/28/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TaitLLCMember	mrcc:TaitLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Hotels, Gaming & Leisure	Hotels, Gaming & Leisure
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5%	5%
Interest Rate		10.25%	8.75%
Maturity		Mar. 28, 2025	Mar. 28, 2025
Principal		$ 4,051	$ 4,083
Fair Value		$ 4,027	$ 3,972
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Teneo Holdings L L C, Senior Secured Loans, due 7/11/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TeneoHoldingsLLCMember	mrcc:SIRVAWorldwideIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Services: Business	Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.35%	5.25%
Interest Rate		10.67%	9.67%
Maturity		Jul. 11, 2025	Jul. 11, 2025
Principal		$ 4,800	$ 4,837
Fair Value		$ 4,809	$ 4,668
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: The Cook & Boardman Group L L C, Senior Secured Loans, due 10/20/2025
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TheCookBoardmanGroupLLCMember	mrcc:TheCookBoardmanGroupLLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Construction & Building	Construction & Building
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.85%	5.75%
Interest Rate		11.18%	9.99%
Maturity		Oct. 20, 2025	Oct. 20, 2025
Principal		$ 2,857	$ 2,879
Fair Value		$ 2,785	$ 2,458
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: The Kleinfelder Group, Inc., Senior Secured Loans, due 11/29/2024
Investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TeneoHoldingsLLCMember
Investment, Type [Extensible Enumeration]			Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]			Services: Business
Investment, Variable Interest Rate, Type [Extensible Enumeration]			London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Spread			5.25%
Interest Rate			9.98%
Maturity			Nov. 29, 2024
Principal			$ 2,362
Fair Value			$ 2,362
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Trident Maritime Systems, Inc ( Revolver), Senior Secured Loans, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TridentMaritimeSystemsIncMember	mrcc:TridentMaritimeSystemsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Aerospace & Defense	Aerospace & Defense
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.60%	4.75%
Interest Rate		10.92%	9.08%
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 319	$ 319
Fair Value		$ 316	$ 122
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, One, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TridentMaritimeSystemsIncMember	mrcc:TridentMaritimeSystemsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Aerospace & Defense	Aerospace & Defense
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.60%	4.75%
Interest Rate		10.99%	9.48%
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 2,422	$ 2,445
Fair Value		$ 2,399	$ 2,443
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, Two, due 2/26/2027
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:TridentMaritimeSystemsIncMember	mrcc:TridentMaritimeSystemsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Aerospace & Defense	Aerospace & Defense
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		5.60%	4.75%
Interest Rate		10.99%	9.48%
Maturity		Feb. 26, 2027	Feb. 26, 2027
Principal		$ 746	$ 746
Fair Value		$ 739	$ 746
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, One, due 12/14/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Truck-LiteCo.LLCMember	mrcc:Truck-LiteCo.LLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.69%	11.14%
Maturity		Dec. 14, 2026	Dec. 14, 2026
Principal		$ 1,678	$ 1,691
Fair Value		$ 1,678	$ 1,690
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, Two, due 12/14/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Truck-LiteCo.LLCMember	mrcc:Truck-LiteCo.LLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.69%	11.14%
Maturity		Dec. 14, 2026	Dec. 14, 2026
Principal		$ 249	$ 251
Fair Value		$ 249	$ 250
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Truck-Lite Co., LLC, Senior Secured Loans, Three, due 12/14/2026
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:Truck-LiteCo.LLCMember	mrcc:Truck-LiteCo.LLCMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		6.25%	6.25%
Interest Rate		11.69%	11.14%
Maturity		Dec. 14, 2026	Dec. 14, 2026
Principal		$ 43	$ 43
Fair Value		$ 43	$ 43
MRCC Senior Loan Fund I, LLC | Investment, Identifier [Axis]: Wheel Pros, Inc., Senior Secured Loans, due 5/11/2028
Investments
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:WheelProsIncMember	mrcc:WheelProsIncMember
Investment, Type [Extensible Enumeration]		Senior Secured Loans	Senior Secured Loans
Investment, Industry Sector [Extensible Enumeration]		Automotive	Automotive
Investment, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]	London Interbank Offered Rate [Member]
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Spread		4.61%	4.50%
Interest Rate		9.94%	8.82%
Maturity		May 11, 2028	May 11, 2028
Principal			$ 1,932
Fair Value			1,321
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments
Investments
Fair Value		$ 148,152
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans
Investments
Principal		170,361
Fair Value		$ 148,077	$ 183,150
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Automotive
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 3,848	$ 5,828
Fair Value		$ 3,314	$ 4,690
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Beverage, Food & Tobacco
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 3,553	$ 4,647
Fair Value		$ 3,551	$ 3,996
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Capital Equipment
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 5,705	$ 10,537
Fair Value		$ 4,872	$ 9,323
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Chemicals, Plastics & Rubber
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 5,352	$ 5,392
Fair Value		$ 4,829	$ 5,263
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Construction & Building
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 2,857	$ 2,879
Fair Value		$ 2,785	$ 2,458
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Consumer Goods: Durable
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 3,755	$ 4,642
Fair Value		$ 3,152	$ 3,280
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Consumer Goods: Non-Durable
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 2,374	$ 2,393
Fair Value		$ 2,018	$ 1,950
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | FIRE: Finance
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 10,677	$ 10,774
Fair Value		$ 10,624	$ 10,437
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | FIRE: Real Estate
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		International	International
Principal		$ 4,775	$ 4,800
Fair Value		$ 1,892	$ 4,020
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Healthcare & Pharmaceuticals
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 19,404	$ 19,519
Fair Value		16,696	17,250
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | High Tech Industries
Investments
Principal		11,184	11,615
Fair Value		$ 10,854	$ 11,164
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Hotels, Gaming & Leisure
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 12,032	$ 12,121
Fair Value		$ 10,377	$ 10,582
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Advertising, Printing & Publishing
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Principal			$ 4,404
Fair Value			$ 4,131
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Media: Diversified & Production
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 14,710	$ 14,825
Fair Value		12,668	$ 12,775
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Containers, Packaging & Glass
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Principal		4,762	$ 10,297
Fair Value		$ 4,695	$ 10,146
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Energy: Oil & Gas
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 7,544	$ 7,585
Fair Value		$ 7,409	$ 7,429
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Services: Business
Investments
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 25,249	$ 37,388
Fair Value		$ 20,645	$ 34,118
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Services: Consumer
Investments
Investment, Type [Extensible Enumeration]		Senior Secured Loans
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 7,599	$ 7,653
Fair Value		$ 7,541	$ 6,880
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Telecommunications
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 5,361	$ 5,414
Fair Value		$ 4,674	$ 4,614
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Transportation: Cargo
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 4,917	$ 4,955
Fair Value		4,880	$ 4,955
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Utilities: Oil & Gas
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]			country:US
Principal		1,907	$ 1,923
Fair Value		$ 1,870	$ 1,858
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Wholesale
Investments
Investment, Issuer Geographic Region [Extensible Enumeration]		country:US	country:US
Principal		$ 4,736	$ 4,774
Fair Value		3,658	4,219
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Senior Secured Loans | Aerospace & Defense
Investments
Principal		8,060	8,083
Fair Value		5,073	$ 7,612
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Equity Securities
Investments
Fair Value		75
MRCC Senior Loan Fund I, LLC | Non-controlled/non-affiliate company investments | Equity Securities | Consumer Goods: Durable
Investments
Fair Value		$ 75

Investments - SLF Balance Sheet

Investments - SLF Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Assets
Fair Value	$ 518,284	$ 541,040
Cash	5,324	5,450	$ 7,129	$ 2,622
Restricted cash				$ 15,459
Other assets	301	541
Total assets	542,536	564,995
Liabilities
Revolving credit facility	331,100	334,600
Less: Unamortized deferred financing costs	(3,566)	(4,486)
Total debt, less unamortized deferred financing costs	327,534	330,114
Interest payable	1,621	3,041
Accounts payable and accrued expenses	2,293	3,220
Total liabilities	334,981	339,976
Total net assets	207,555	225,019
SLF
Assets
Fair Value	148,152	183,150
Cash	2,104	1,608
Restricted cash	5,523	6,454
Interest receivable	1,246	1,613
Other assets	1,642	5
Total assets	158,667	192,830
Liabilities
Revolving credit facility	92,064	122,215
Less: Unamortized deferred financing costs	(919)	(1,518)
Total debt, less unamortized deferred financing costs	91,145	120,697
Interest payable	621	769
Accounts payable and accrued expenses	363	346
Total liabilities	92,129	121,812
Total net assets	66,538	71,018
Total liabilities and members' capital	$ 158,667	$ 192,830

Investments - SLF, Net increase

Investments - SLF, Net increase (decrease) in members' capital (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Investment income:
Total investment income	$ 15,643	$ 15,916	$ 48,794	$ 41,402
Expenses:
Interest and other debt financing expenses	5,874	4,263	17,178	11,961
Professional fees	189	212	541	740
Operating expenses before base management fee and incentive fee waivers	10,128	8,788	30,328	24,021
Net investment income	5,420	6,260	17,971	16,672
Net gain (loss):
Net change in unrealized gain (loss) on investments	(5,682)	(5,379)	18,249	(21,180)
Net gain (loss)	(5,656)	(7,009)	(19,184)	(23,938)
Net increase (decrease) in net assets resulting from operations	(236)	(749)	(1,213)	(7,266)
SLF
Investment income:
Interest income	3,936	4,075	14,017	10,593
Total investment income	3,936	4,075	14,017	10,593
Expenses:
Interest and other debt financing expenses	2,194	1,669	6,848	3,866
Professional fees	146	203	549	580
Operating expenses before base management fee and incentive fee waivers	2,340	1,872	7,397	4,446
Net investment income	1,596	2,203	6,620	6,147
Net gain (loss):
Net realized gain (loss) on investments	(274)		(814)
Net change in unrealized gain (loss) on investments	(2,073)	(2,416)	(4,886)	(10,909)
Net gain (loss)	(2,347)	(2,416)	(5,700)	(10,909)
Net increase (decrease) in net assets resulting from operations	$ (751)	$ (213)	$ 920	$ (4,762)

Fair Value Measurements - Fair

Fair Value Measurements - Fair value measurements of investments and foreign currency forward contracts, by major class according to the fair value hierarchy (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Measurements
Total investments	$ 483,766	$ 502,980
Recurring
Fair Value Measurements
Total investments	518,284	541,040
Foreign currency forward contracts asset (liability)		1,507
Recurring | Senior Secured Loans
Fair Value Measurements
Total investments	416,316	434,023
Recurring | Unitranche Secured Loans
Fair Value Measurements
Total investments	13,548	20,633
Recurring | Junior Secured Loans
Fair Value Measurements
Total investments	27,425	22,193
Recurring | Equity Securities
Fair Value Measurements
Total investments	27,726	28,682
Recurring | Level 1
Fair Value Measurements
Total investments	229	294
Recurring | Level 1 | Equity Securities
Fair Value Measurements
Total investments	229	294
Recurring | Level 2
Fair Value Measurements
Foreign currency forward contracts asset (liability)		1,507
Recurring | Level 3
Fair Value Measurements
Total investments	484,786	505,237
Recurring | Level 3 | Senior Secured Loans
Fair Value Measurements
Total investments	416,316	434,023
Recurring | Level 3 | Unitranche Secured Loans
Fair Value Measurements
Total investments	13,548	20,633
Recurring | Level 3 | Junior Secured Loans
Fair Value Measurements
Total investments	27,425	22,193
Recurring | Level 3 | Equity Securities
Fair Value Measurements
Total investments	27,497	28,388
Recurring | Measured at NAV
Fair Value Measurements
Total investments	$ 33,269	$ 35,509

Fair Value Measurements - Contr

Fair Value Measurements - Contractual interest rates (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Minimum
Fair Value Measurements
Contractual interest rates on loans (in percent)	8%	8%
Maximum
Fair Value Measurements
Contractual interest rates on loans (in percent)	20.53%	19.50%

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of beginning and ending balances for investments at fair value that use Level 3 inputs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Reconciliation of beginning and ending balances for investments at fair value that use Level 3 inputs
Balance at the beginning	$ 480,614	$ 497,940	$ 505,237	$ 519,527
Net realized gain (loss) on investments	6	(1,667)	(39,020)	(1,750)
Net change in unrealized gain (loss) on investments	(4,387)	(5,068)	22,062	(17,106)
Purchases of investments and other adjustments to cost	15,298	52,915	60,270	99,105
Proceeds from principal payments and sales of investments	(6,745)	(73,027)	(63,763)	(128,683)
Balance at the end	484,786	471,093	484,786	471,093
Total net change in unrealized gain (loss) on investments attributable to Level 3 investments still held	(5,664)	(6,132)	$ (9,596)	(16,041)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Derivative and Foreign Currency Transaction Price Change, Realized Gain (Loss), Operating, before Tax
Fair value, assets, transfers among Levels 1, 2 and 3			$ 0	0
Senior Secured Loans
Reconciliation of beginning and ending balances for investments at fair value that use Level 3 inputs
Balance at the beginning	415,873	415,244	434,023	423,700
Net realized gain (loss) on investments		(1,672)	(9,787)	(1,693)
Net change in unrealized gain (loss) on investments	(3,554)	(3,788)	(2,734)	(8,838)
Purchases of investments and other adjustments to cost	13,259	52,370	54,107	88,950
Proceeds from principal payments and sales of investments	(5,971)	(59,925)	(53,234)	(99,890)
Reclassifications	(3,291)		(6,059)
Balance at the end	416,316	402,229	416,316	402,229
Unitranche Secured Loans
Reconciliation of beginning and ending balances for investments at fair value that use Level 3 inputs
Balance at the beginning	13,400	34,114	20,633	51,494
Net realized gain (loss) on investments			(24,768)	(94)
Net change in unrealized gain (loss) on investments	(43)	10	24,746	(5,146)
Purchases of investments and other adjustments to cost	210	15	295	3,253
Proceeds from principal payments and sales of investments	(19)	(13,096)	(7,358)	(28,464)
Balance at the end	13,548	21,043	13,548	21,043
Junior Secured Loans
Reconciliation of beginning and ending balances for investments at fair value that use Level 3 inputs
Balance at the beginning	25,307	19,745	22,193	14,364
Net realized gain (loss) on investments		(1)		(1)
Net change in unrealized gain (loss) on investments	(690)	1,314	(1,743)	992
Purchases of investments and other adjustments to cost	1,746	368	4,564	6,071
Proceeds from principal payments and sales of investments	(749)		(2,168)
Reclassifications	1,811		4,579
Balance at the end	27,425	21,426	27,425	21,426
Equity Securities
Reconciliation of beginning and ending balances for investments at fair value that use Level 3 inputs
Balance at the beginning	26,034	28,837	28,388	29,969
Net realized gain (loss) on investments	6	6	(4,465)	38
Net change in unrealized gain (loss) on investments	(100)	(2,604)	1,793	(4,114)
Purchases of investments and other adjustments to cost	83	162	1,304	831
Proceeds from principal payments and sales of investments	(6)	(6)	(1,003)	(329)
Reclassifications	1,480		1,480
Balance at the end	$ 27,497	$ 26,395	$ 27,497	$ 26,395

Fair Value Measurements - Valua

Fair Value Measurements - Valuation techniques and significant unobservable inputs used in recurring Level 3 fair value measurements of assets and liabilities (Details) $ in Thousands	Sep. 30, 2023 USD ($) item	Dec. 31, 2022 USD ($) item
Fair Value Measurements
Fair Value | $	$ 483,766	$ 502,980
Loans at fair value where valuation (unadjusted) is obtained from third-party pricing service or broker quote | $	1,020	2,257
2026 Notes
Fair Value Measurements
Estimated fair value of notes | $	116,903	116,995
Senior Secured Loans | Discounted cash flow | EBITDA multiples
Fair Value Measurements
Fair Value | $	$ 270,084	$ 276,433
Senior Secured Loans | Discounted cash flow | EBITDA multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.105	0.093
Senior Secured Loans | Discounted cash flow | EBITDA multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.058	0.038
Senior Secured Loans | Discounted cash flow | EBITDA multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.220	0.186
Senior Secured Loans | Discounted cash flow | EBITDA Market yields | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.137	0.124
Senior Secured Loans | Discounted cash flow | EBITDA Market yields | Minimum
Fair Value Measurements
Investments, measurement input	0.095	0.087
Senior Secured Loans | Discounted cash flow | EBITDA Market yields | Maximum
Fair Value Measurements
Investments, measurement input	0.293	0.223
Senior Secured Loans | Discounted cash flow | Revenue Market yields | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.126	0.134
Senior Secured Loans | Discounted cash flow | Revenue Market yields | Minimum
Fair Value Measurements
Investments, measurement input	0.110	0.100
Senior Secured Loans | Discounted cash flow | Revenue Market yields | Maximum
Fair Value Measurements
Investments, measurement input	0.175	0.220
Senior Secured Loans | Discounted cash flow | Revenue multiples
Fair Value Measurements
Fair Value | $	$ 108,565	$ 130,199
Senior Secured Loans | Discounted cash flow | Revenue multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.055	0.044
Senior Secured Loans | Discounted cash flow | Revenue multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.008	0.002
Senior Secured Loans | Discounted cash flow | Revenue multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.115	0.123
Senior Secured Loans | Enterprise value | EBITDA multiples
Fair Value Measurements
Fair Value | $	$ 3,104	$ 80
Senior Secured Loans | Enterprise value | EBITDA multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.082	0.080
Senior Secured Loans | Enterprise value | EBITDA multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.055	0.080
Senior Secured Loans | Enterprise value | EBITDA multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.083	0.080
Senior Secured Loans | Enterprise value | Revenue multiples
Fair Value Measurements
Fair Value | $	$ 6,752	$ 5,706
Senior Secured Loans | Enterprise value | Revenue multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.020	0.025
Senior Secured Loans | Enterprise value | Revenue multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.020	0.025
Senior Secured Loans | Enterprise value | Revenue multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.020	0.025
Senior Secured Loans | Enterprise value | Book value multiples
Fair Value Measurements
Fair Value | $	$ 18,020	$ 19,546
Senior Secured Loans | Enterprise value | Book value multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.013	0.012
Senior Secured Loans | Enterprise value | Book value multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.013	0.012
Senior Secured Loans | Enterprise value | Book value multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.013	0.012
Senior Secured Loans | Liquidation | Probability weighting of alternative outcomes
Fair Value Measurements
Fair Value | $	$ 9,191	$ 1,488
Senior Secured Loans | Liquidation | Probability weighting of alternative outcomes | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.958	0.713
Senior Secured Loans | Liquidation | Probability weighting of alternative outcomes | Minimum
Fair Value Measurements
Investments, measurement input	0.324	0.291
Senior Secured Loans | Liquidation | Probability weighting of alternative outcomes | Maximum
Fair Value Measurements
Investments, measurement input	1	1
Unitranche Secured Loans | Discounted cash flow | EBITDA multiples
Fair Value Measurements
Fair Value | $	$ 9,828	$ 17,019
Unitranche Secured Loans | Discounted cash flow | EBITDA multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.090	0.088
Unitranche Secured Loans | Discounted cash flow | EBITDA multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.090	0.088
Unitranche Secured Loans | Discounted cash flow | EBITDA multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.090	0.088
Unitranche Secured Loans | Discounted cash flow | EBITDA Market yields | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.131	0.112
Unitranche Secured Loans | Discounted cash flow | EBITDA Market yields | Minimum
Fair Value Measurements
Investments, measurement input	0.118	0.091
Unitranche Secured Loans | Discounted cash flow | EBITDA Market yields | Maximum
Fair Value Measurements
Investments, measurement input	0.135	0.130
Unitranche Secured Loans | Discounted cash flow | Revenue Market yields | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.130	0.119
Unitranche Secured Loans | Discounted cash flow | Revenue Market yields | Minimum
Fair Value Measurements
Investments, measurement input	0.126	0.116
Unitranche Secured Loans | Discounted cash flow | Revenue Market yields | Maximum
Fair Value Measurements
Investments, measurement input	0.134	0.121
Unitranche Secured Loans | Discounted cash flow | Revenue multiples
Fair Value Measurements
Fair Value | $	$ 3,720	$ 3,614
Unitranche Secured Loans | Discounted cash flow | Revenue multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.090	0.089
Unitranche Secured Loans | Discounted cash flow | Revenue multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.060	0.058
Unitranche Secured Loans | Discounted cash flow | Revenue multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.128	0.125
Junior Secured Loans | Discounted cash flow | Market yields
Fair Value Measurements
Fair Value | $	$ 21,338	$ 20,311
Junior Secured Loans | Discounted cash flow | Market yields | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.137	0.136
Junior Secured Loans | Discounted cash flow | Market yields | Minimum
Fair Value Measurements
Investments, measurement input	0.129	0.123
Junior Secured Loans | Discounted cash flow | Market yields | Maximum
Fair Value Measurements
Investments, measurement input	0.156	0.204
Junior Secured Loans | Discounted cash flow | Revenue Market yields | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.133
Junior Secured Loans | Discounted cash flow | Revenue Market yields | Minimum
Fair Value Measurements
Investments, measurement input	0.120
Junior Secured Loans | Discounted cash flow | Revenue Market yields | Maximum
Fair Value Measurements
Investments, measurement input	0.161
Junior Secured Loans | Discounted cash flow | Revenue multiples
Fair Value Measurements
Fair Value | $	$ 1,428
Junior Secured Loans | Discounted cash flow | Revenue multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.004
Junior Secured Loans | Discounted cash flow | Revenue multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.001
Junior Secured Loans | Discounted cash flow | Revenue multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.008
Junior Secured Loans | Enterprise value | Revenue multiples
Fair Value Measurements
Fair Value | $	$ 2,574
Junior Secured Loans | Enterprise value | Revenue multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.020
Junior Secured Loans | Enterprise value | Revenue multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.020
Junior Secured Loans | Enterprise value | Revenue multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.020
Junior Secured Loans | Liquidation | Probability weighting of alternative outcomes
Fair Value Measurements
Fair Value | $	$ 2,085	$ 1,882
Junior Secured Loans | Liquidation | Probability weighting of alternative outcomes | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	2.503	2.258
Junior Secured Loans | Liquidation | Probability weighting of alternative outcomes | Minimum
Fair Value Measurements
Investments, measurement input	0	2.258
Junior Secured Loans | Liquidation | Probability weighting of alternative outcomes | Maximum
Fair Value Measurements
Investments, measurement input	2.503	2.258
Equity Securities | Discounted cash flow | EBITDA multiples
Fair Value Measurements
Fair Value | $	$ 357	$ 397
Equity Securities | Discounted cash flow | EBITDA multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.060	0.070
Equity Securities | Discounted cash flow | EBITDA multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.060	0.070
Equity Securities | Discounted cash flow | EBITDA multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.060	0.070
Equity Securities | Discounted cash flow | EBITDA Market yields | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.275
Equity Securities | Discounted cash flow | EBITDA Market yields | Minimum
Fair Value Measurements
Investments, measurement input	0.275
Equity Securities | Discounted cash flow | EBITDA Market yields | Maximum
Fair Value Measurements
Investments, measurement input	0.275
Equity Securities | Enterprise value | EBITDA multiples
Fair Value Measurements
Fair Value | $	$ 18,542	$ 16,630
Equity Securities | Enterprise value | EBITDA multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.092	0.090
Equity Securities | Enterprise value | EBITDA multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.055	0.038
Equity Securities | Enterprise value | EBITDA multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.193	0.160
Equity Securities | Enterprise value | Revenue multiples
Fair Value Measurements
Fair Value | $	$ 5,736	$ 7,502
Equity Securities | Enterprise value | Revenue multiples | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.021	0.023
Equity Securities | Enterprise value | Revenue multiples | Minimum
Fair Value Measurements
Investments, measurement input	0.007	0.002
Equity Securities | Enterprise value | Revenue multiples | Maximum
Fair Value Measurements
Investments, measurement input	0.115	0.123
Equity Securities | Option pricing model | Volatility
Fair Value Measurements
Fair Value | $	$ 2,442	$ 2,173
Equity Securities | Option pricing model | Volatility | Weighted Average Mean
Fair Value Measurements
Investments, measurement input	0.630	0.666
Equity Securities | Option pricing model | Volatility | Minimum
Fair Value Measurements
Investments, measurement input	0.320	0.494
Equity Securities | Option pricing model | Volatility | Maximum
Fair Value Measurements
Investments, measurement input	0.725	0.700

Transactions with Affiliated _3

Transactions with Affiliated Companies - Fair Value Roll Forward (Details) - USD ($) $ in Thousands		6 Months Ended	9 Months Ended		12 Months Ended
	Dec. 29, 2022	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 541,040
Fair value at the ending			$ 518,284		$ 541,040
Stock issued (in shares)	4,940
Percentage of preferred units obtained	22.30%
Investment, Identifier [Axis]: 360 Holdco, Inc. ( Delayed Draw), Senior Secured Loans, due 8/2/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: 360 Holdco, Inc., Senior Secured Loans, due 8/2/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A P C O Worldwide, Inc, Equity Securities, Class A voting common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:APCOWorldwideIncMember		mrcc:APCOWorldwideIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 921
Fair value at the ending			$ 1,098		$ 921
Number of shares held			100
Number of units held					100
Investment, Identifier [Axis]: A Q Carver Buyer, Inc., Senior Secured Loans, due 9/23/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A S G I I, L L C ( Delayed Draw), Unitranche Secured Loans, 5/25/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ASGIILLCMember		mrcc:ASGIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 51
Fair value at the ending			$ 140		$ 51
Investment, Identifier [Axis]: A S G I I, L L C, Unitranche Secured Loans, due 5/25/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ASGIILLCMember		mrcc:ASGIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,900
Fair value at the ending			$ 1,900		$ 1,900
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Delayed Draw), Senior Secured Loans, due 12/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Revolver), Senior Secured Loans, due 12/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C, Senior Secured Loans, due 12/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Ad Theorent Holding Company, Inc. Equity Securities, common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AdTheorentHoldingCompanyIncMember		mrcc:AdTheorentHoldingCompanyIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 294
Fair value at the ending			$ 229		$ 294
Number of shares held			177,362		177,362
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 12/21/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmeliaHoldingIiLlcDelayedDrawMember		mrcc:AmeliaHoldingIiLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 293
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ArcstorMidcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 107
Investment, Identifier [Axis]: Amelia Holding II, LLC (Revolver), Due 12/21/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmeliaHoldingIiLlcRevolverMember		mrcc:AmeliaHoldingIiLlcMember
Investment, Identifier [Axis]: Amelia Holding II, LLC, Due 12/21/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmeliaHoldingIiLlcMember		mrcc:AmeliaHoldingIiLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,940
Fair value at the ending			$ 2,016		$ 1,940
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmeliaHoldingIiLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 28
Number of units held			0.1
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities, Warrant
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:AmeliaHoldingIiLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Warrants to purchase percentage of equity					0.10%
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Delayed Draw), Senior Secured Loans, due 6/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,539
Fair value at the ending			$ 1,293		$ 1,539
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Revolver), Senior Secured Loans, due 6/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 118
Fair value at the ending			$ 123		$ 118
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C, Equity Securities, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 69
Fair value at the ending			$ 56		$ 69
Warrants to purchase percentage of equity			0.20%		0.20%
Investment, Identifier [Axis]: American Community Homes, Inc. ( Revolver), Senior Secured Loans Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities Due 12/18/2024, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 264		$ 264	$ 264
Net unrealized gain (loss)				$ (264)
Warrants to purchase percentage of equity				22.30%
Number of shares held			4,940
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities, Common Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Number of shares held					4,940
Percentage of units held			4,940%
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Acquisition Date 3/29/2019
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 4,357	$ 3,694	$ 4,357	$ 4,357
PIK Interest (cost)			481	192
Net unrealized gain (loss)			(794)	(821)
Fair value at the ending			$ 3,381	3,728	$ 3,694
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,694
Fair value at the ending			$ 3,381		$ 3,694
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Acquisition Date 8/10/2018
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 3,164	$ 1,996	3,164	3,164
PIK Interest (cost)			259	104
Net unrealized gain (loss)			(429)	(1,254)
Fair value at the ending			$ 1,826	2,014	$ 1,996
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,996
Fair value at the ending			$ 1,826		$ 1,996
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Acquisition Date 7/22/2014
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 10,457	$ 8,953	10,457	10,457
PIK Interest (cost)			1,165	466
Net unrealized gain (loss)			(1,925)	(1,889)
Fair value at the ending			$ 8,193	9,034	$ 8,953
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 8,953
Fair value at the ending			$ 8,193		$ 8,953
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Acquisition Date 12/30/2019
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 99	$ 85	99	99
PIK Interest (cost)			11	4
Net unrealized gain (loss)			(19)	(18)
Fair value at the ending			$ 77	85	$ 85
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 85
Fair value at the ending			$ 77		$ 85
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Acquisition Date 9/30/2019
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 20	$ 17	20	20
PIK Interest (cost)			2	1
Net unrealized gain (loss)			(3)	(3)
Fair value at the ending			$ 16	18	$ 17
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 17
Fair value at the ending			$ 16		$ 17
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Acquisition Date 5/24/2017
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 634	$ 543	634	634
PIK Interest (cost)			70	28
Net unrealized gain (loss)			(116)	(114)
Fair value at the ending			$ 497	548	$ 543
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 543
Fair value at the ending			$ 497		$ 543
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Acquisition Date 7/22/2014
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 4,753	$ 4,258	4,753	4,753
PIK Interest (cost)			757	384
Net unrealized gain (loss)			(985)	(888)
Fair value at the ending			$ 4,030	4,249	$ 4,258
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,258
Fair value at the ending			$ 4,030		$ 4,258
Investment, Identifier [Axis]: Aras Corporation ( Revolver), Senior Secured Loans, due 4/13/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ArasCorporationMember		mrcc:ArasCorporationMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 50
Fair value at the ending			$ 110		$ 50
Investment, Identifier [Axis]: Aras Corporation, Senior Secured Loans, due 4/13/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ArasCorporationMember		mrcc:ArasCorporationMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,167
Fair value at the ending			$ 2,231		$ 2,167
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, One, due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ArcstorMidcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2,419
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, Two, due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ArcstorMidcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 155
Investment, Identifier [Axis]: Arcstor Midco, LLC, Due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ArcstorMidcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,122
Fair value at the ending					$ 4,122
Investment, Identifier [Axis]: Ascent Midco, L L C ( Revolver), Senior Secured Loans Due 2/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]		Ascent Midco, L L C [ Member]
Investment, Identifier [Axis]: Ascent Midco, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]		Ascent Midco, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 2,554	$ 1,969	2,554	$ 2,554
Net unrealized gain (loss)			(55)	(1,136)
Fair value at the ending			$ 1,914	$ 1,418	$ 1,969
Number of shares held				2,032,258
Number of units held			2,032,258		2,032,258
Investment, Identifier [Axis]: Ascent Midco, L L C, Senior Secured Loans Due 2/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Ascent Midco, L L C [ Member]		Ascent Midco, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 6,392	$ 6,217	$ 6,392	$ 6,392
Sales and paydowns (cost)			(6,175)	(130)
Discount accretion			16	19
Net unrealized gain (loss)			$ (58)	(121)
Fair value at the ending				6,160	$ 6,217
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 522
Fair value at the ending			$ 418		$ 522
Number of units held			297,197		297,197
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Five, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 399
Fair value at the ending			$ 394		$ 399
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Four, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 794
Fair value at the ending			$ 779		$ 794
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, One, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,915
Fair value at the ending			$ 1,878		$ 1,915
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Three, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 275
Fair value at the ending			$ 270		$ 275
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Two, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 467
Fair value at the ending			$ 458		$ 467
Investment, Identifier [Axis]: Attom Intermediate Holdco, LLC (Revolver), Senior Secured Loans, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 118
Investment, Identifier [Axis]: Avalara, Inc. (Revolver), Senior Secured Loans, due 10/19/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AvalaraInc.Member		mrcc:AvalaraInc.Member
Investment, Identifier [Axis]: Avalara, Inc. Senior Secured Loans, due 10/19/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:AvalaraInc.Member		mrcc:AvalaraInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,900
Fair value at the ending			$ 4,040		$ 3,900
Investment, Identifier [Axis]: Avison Young ( U S A) Inc., Senior Secured Loans, due 1/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BLSTOperatingCompanyLLCMember		mrcc:BLSTOperatingCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 420
Fair value at the ending			$ 420		$ 420
Number of shares held			139,883
Number of units held					139,883
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Senior Secured Loans, due 8/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BLSTOperatingCompanyLLCMember		mrcc:BLSTOperatingCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 571
Fair value at the ending			$ 600		$ 571
Investment, Identifier [Axis]: Bluesight, Inc (Revolver) Senior Secured Loans 7/17/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BluesightIncMember
Investment, Identifier [Axis]: Bluesight, Inc Senior Secured Loans, 7/17/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BluesightIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,940
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Class B Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BluesightIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Number of units held			11,087
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BluesightIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 21
Number of units held			21
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Delayed Draw) , Senior Secured Loans, due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Revolver), Senior Secured Loans, due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 389
Fair value at the ending					$ 389
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings), Senior Secured Loans, due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 12,898
Fair value at the ending					$ 12,898
Investment, Identifier [Axis]: Bonterra, LLC (Revolver), Senior Secured Loans, Due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, One, Due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 13,135
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, Two, Due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,902
Investment, Identifier [Axis]: Born To Run, L L C ( Delayed Draw) Senior Secured Loans, due 4/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:BornToRunLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 452
Fair value at the ending					$ 452
Investment, Identifier [Axis]: Born To Run, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BornToRunLLCMember		mrcc:BornToRunLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 233
Fair value at the ending					$ 233
Number of shares held			269,438
Number of units held					269,438
Investment, Identifier [Axis]: Born To Run, L L C, Senior Secured Loans, due 4/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BornToRunLLCMember		mrcc:BornToRunLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,318
Fair value at the ending			$ 2,662		$ 3,318
Investment, Identifier [Axis]: Born To Run, LLC, Senior Secured Loans, Two, Due 4/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BornToRunLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 363
Investment, Identifier [Axis]: Brickell Bay Acquisition Corp, Senior Secured Loans, due 2/12/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BrickellBayAcquisitionCorpMember		mrcc:BrickellBayAcquisitionCorpMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,847
Fair value at the ending			$ 1,866		$ 1,847
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, One, due 11/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, Two, due 11/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Burroughs, Inc. ( Revolver), Senior Secured Loans, due 12/22/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:BurroughsInc.Member
Investment, Identifier [Axis]: Burroughs, Inc. (Revolver), Senior Secured Loans, due 12/22/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BurroughsInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,020
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, One, due 12/22/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:BurroughsInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 4,976
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, due 12/22/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:BurroughsInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,201
Fair value at the ending					$ 5,201
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, One, due 4/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, Two, due 4/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC) (Revolver), Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 550		550	$ 550
Purchases (cost)				92
Sales and paydowns (cost)				(620)
Net unrealized gain (loss)				$ (22)
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Equity Securities, Common Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Number of shares held			58,779	58,779
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, One
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Net realized gain (loss)				$ (1)
Net unrealized gain (loss)				1
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, Two
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 4,561	$ 146	4,561	$ 4,561
Sales and paydowns (cost)				(4,497)
Net unrealized gain (loss)			$ (146)	82
Fair value at the ending				146	$ 146
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, One, due 12/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CgiAutomatedManufacturingLlcMember		mrcc:CgiAutomatedManufacturingLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,975
Fair value at the ending			$ 3,846		$ 3,975
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, Two, due 12/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCPShawAcquisitioncoLLCMember		mrcc:CgiAutomatedManufacturingLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,141
Fair value at the ending			$ 1,104		$ 1,141
Investment, Identifier [Axis]: Cadent, L L C ( Revolver), Senior Secured Loans, due 9/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Cadent, L L C, Senior Secured Loans, due 9/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Calabrio, Inc. ( Revolver), Senior Secured Loans, due 4/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CalabrioIncMember		mrcc:CalabrioIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 233
Fair value at the ending			$ 234		$ 233
Investment, Identifier [Axis]: Calabrio, Inc., Senior Secured Loans, due 4/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CalabrioIncMember		mrcc:CalabrioIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,379
Fair value at the ending			3,400		$ 3,379
Investment, Identifier [Axis]: California Pizza Kitchen, Inc., Equity Securities, Common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:CaliforniaPizzaKitchenInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,266
Fair value at the ending					$ 1,266
Number of units held					78,699
Investment, Identifier [Axis]: Cano Health, L L C, Senior Secured Loans, due 11/23/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Caravel Autism Health LLC One Senior Secured Loans due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CaravelAutismHealthLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,368
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Delayed Draw), Senior Secured Loans, due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:CaravelAutismHealthLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 173
Fair value at the ending					$ 173
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Revolver), Senior Secured Loans, due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CaravelAutismHealthLLCMember		mrcc:CaravelAutismHealthLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,048
Fair value at the ending			$ 484		$ 1,048
Investment, Identifier [Axis]: Caravel Autism Health, L L C, Senior Secured Loans, due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CaravelAutismHealthLLCMember		mrcc:CaravelAutismHealthLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,630
Fair value at the ending			$ 4,923		$ 4,630
Investment, Identifier [Axis]: Cassavant Holdings, L L C, Unitranche Secured Loans, due 9/8/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CassavantHoldingsLLCMember		mrcc:CassavantHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 7,436
Fair value at the ending			$ 7,578		$ 7,436
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Delayed Draw), Senior Secured Loans, due 4/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 337
Fair value at the ending			$ 286		$ 337
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Revolver), Senior Secured Loans, due 4/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 719
Fair value at the ending			$ 870		$ 719
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C, Senior Secured Loans, due 4/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,296
Fair value at the ending			$ 2,798		$ 3,296
Investment, Identifier [Axis]: Chess.com, L L C ( Revolver), Senior Secured Loans, due 12/31/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:Chess.comLLCMember		mrcc:Chess.comLLCMember
Investment, Identifier [Axis]: Chess.com, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:Chess.comLLCMember		mrcc:Chess.comLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 50
Fair value at the ending			$ 55		$ 50
Number of units held			2		2
Investment, Identifier [Axis]: Chess.com, L L C, Senior Secured Loans, due 12/31/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:Chess.comLLCMember		mrcc:Chess.comLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,866
Fair value at the ending			$ 5,866		$ 5,866
Investment, Identifier [Axis]: Corel Inc., Senior Secured Loans, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Crownpeak Technology Inc. (Revolver) Senior Secured Loans, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 67
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Four, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,333
Fair value at the ending			$ 3,333		$ 3,333
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans One, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,000
Fair value at the ending			$ 4,000		$ 4,000
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Three, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 60
Fair value at the ending			$ 60		$ 60
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Two, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,273
Fair value at the ending			$ 1,273		$ 1,273
Investment, Identifier [Axis]: Curion Holdings, L L C, Equity Securities, Common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					Curion Holdings, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Number of shares held					58,779
Investment, Identifier [Axis]: D S Parent, Inc., Senior Secured Loans, due 12/8/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Destination Media, Inc. ( Revolver), Senior Secured Loans, due 4/7/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:DestinationMediaIncMember
Investment, Identifier [Axis]: Destination Media, Inc. (Delayed Draw), Senior Secured Loans, due 6/21/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DestinationMediaIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 29
Investment, Identifier [Axis]: Destination Media, Inc. (Revolver), Senior Secured Loans, due 6/21/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DestinationMediaIncMember
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 4/7/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:DestinationMediaIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 377
Fair value at the ending					$ 377
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 6/21/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DestinationMediaIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,001
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, One, Class A-1 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DoradoAcquisitionIncMember		mrcc:DoradoAcquisitionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 215
Fair value at the ending			$ 209		$ 215
Number of units held			189,922		189,922
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, Two, Class A-2 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DoradoAcquisitionIncMember		mrcc:DoradoAcquisitionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 224
Fair value at the ending			$ 207		$ 224
Number of units held			189,922		189,922
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Delayed Draw) , Senior Secured Loans, due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:DoradoAcquisitionInc.Member
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Revolver) , Senior Secured Loans, due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DoradoAcquisitionInc.Member		mrcc:DoradoAcquisitionInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 596
Fair value at the ending					$ 596
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, One, due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DoradoAcquisitionInc.Member		mrcc:DoradoAcquisitionInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,928
Fair value at the ending			$ 4,778		$ 4,928
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, Two, Due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DoradoAcquisitionInc.Member		mrcc:DoradoAcquisitionInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,074
Fair value at the ending			$ 3,960		$ 4,074
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Delayed Draw), Senior Secured Loans, due 9/1/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 102
Fair value at the ending			$ 389		$ 102
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Revolver), Senior Secured Loans, due 9/1/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 126
Fair value at the ending			$ 132		$ 126
Number of units held			130,433		130,433
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Senior Secured Loans, due 9/1/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,971
Fair value at the ending			$ 2,978		$ 2,971
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, One, due 10/1/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, Two, due 10/1/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Drilling Info Holdings, Inc., Senior Secured Loans, due 7/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Education Corporation of America, Equity Securities, Series G Preferred Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EducationCorporationofAmericaMember		mrcc:EducationCorporationofAmericaMember
Transactions with Affiliated Companies, Fair value Roll Forward
Number of shares held			8,333		8,333
Investment, Identifier [Axis]: Education Corporation of America, Junior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EducationCorporationofAmericaMember		mrcc:EducationCorporationofAmericaMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,882
Fair value at the ending			$ 2,085		$ 1,882
Investment, Identifier [Axis]: Elevate Textiles, Inc. (fka International Textile Group, Inc.), Senior Secured Loans, due 9/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C ( Delayed Draw), Senior Secured Loans, due 4/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C, Senior Secured Loans, due 4/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc. ( Revolver), Senior Secured Loans, due 3/7/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, One, due 3/7/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, Two,due 3/7/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Equine Network, L L C, (Delayed Draw), Senior Secured Loans, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:EquineNetworkLLCMember
Investment, Identifier [Axis]: Equine Network, L L C, (Revolver), Senior Secured Loans, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:EquineNetworkLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 127
Fair value at the ending					$ 127
Investment, Identifier [Axis]: Equine Network, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:EquineNetworkLLCMember		mrcc:EquineNetworkLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 109
Fair value at the ending			$ 115		$ 109
Number of units held			108		108
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, One, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:EquineNetworkLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,709
Fair value at the ending					$ 1,709
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, Two, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:EquineNetworkLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 775
Fair value at the ending					$ 775
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc. ( Revolver), Senior Secured Loans, due 4/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc., Senior Secured Loans, due 4/27/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Express Wash Acquisition Company, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 118
Fair value at the ending			$ 75		$ 118
Number of shares held			121,311
Number of units held					121,311
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC (Revolver), Senior Secured Loans, due 7/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 208
Fair value at the ending			$ 209		$ 208
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, One, Due 7/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 8,119
Fair value at the ending			$ 7,067		$ 8,119
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, Two, Due 7/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,521
Fair value at the ending			$ 1,517		$ 1,521
Investment, Identifier [Axis]: Familia Dental Group Holdings, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Familia Dental Group Holdings, LLC		Familia Dental Group Holdings, LLC
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 1,919	$ 2,625	1,919	$ 1,919
Purchases (cost)			122	183
Net unrealized gain (loss)			(396)	406
Fair value at the ending			$ 2,351	$ 2,508	$ 2,625
Number of shares held			1,212
Number of units held			1,212	1,158	1,176
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Junior Secured Loans, due 6/28/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FloridaEastCoastIndustriesLLCMember		mrcc:FloridaEastCoastIndustriesLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,784
Fair value at the ending			845		$ 1,784
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Senior Secured Loans, due 6/28/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:FloridaEastCoastIndustriesLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			619
Fair value at the ending					$ 619
Investment, Identifier [Axis]: Forman Mills, Inc, Equity Securities, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:FormanMillsInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			155
Fair value at the ending					$ 155
Warrants to purchase percentage of equity					2.60%
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, One, due 4/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:FormanMillsIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,253
Fair value at the ending					$ 1,253
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, Two, due 4/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:FormanMillsIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 6,698
Fair value at the ending					$ 6,698
Investment, Identifier [Axis]: Forman Mills, Inc., Senior Secured Loans, due 6/20/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:FormanMillsInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 965
Investment, Identifier [Axis]: GC Champion Acquisition LLC (Delayed Draw), Senior Notes, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:GCChampionAcquisitionLLCMember
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:GCChampionAcquisitionLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,503
Fair value at the ending					$ 2,503
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, One, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:GCChampionAcquisitionLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2,513
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Two, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:GCChampionAcquisitionLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 698
Investment, Identifier [Axis]: GC Champion Acquisition Llc Senior Notes Three Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:GCChampionAcquisitionLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2,112
Investment, Identifier [Axis]: H A H Group Holding Company L L C, Senior Secured Loans, due 10/29/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H A L O Buyer, Inc., Senior Secured Loans, due 6/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans , Two
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember		mrcc:HFZCapitalGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 5,420	$ 5,805	$ 5,420	$ 5,420
Net unrealized gain (loss)			289	288
Fair value at the ending			$ 6,094	5,708	$ 5,805
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans, One
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HFZCapitalGroupLLCMember		mrcc:HFZCapitalGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 15,084	$ 16,159	15,084	$ 15,084
Net unrealized gain (loss)			803	804
Fair value at the ending			$ 16,962	15,888	$ 16,159
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc. ( Revolver), Senior Secured Loans, due 7/9/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HS4AcquisitioncoIncMember		mrcc:HS4AcquisitioncoIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 407
Fair value at the ending			$ 530		$ 407
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc., Senior Secured Loans, due 7/9/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HS4AcquisitioncoIncMember		mrcc:HS4AcquisitioncoIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 9,855
Fair value at the ending			$ 9,804		$ 9,855
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, One, due 12/13/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, Two, due 12/13/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Hastings Manufacturing Company (Revolver), Senior Secured Loans, Due 12/31/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HastingsManufacturingCompanyMember
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, One, Due 12/31/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HastingsManufacturingCompanyMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,858
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, Two, Due 12/31/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HastingsManufacturingCompanyMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 665
Investment, Identifier [Axis]: Hastings Manufacturing Company, Senior Secured Loans, due 4/24/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:HastingsManufacturingCompanyMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,026
Fair value at the ending					$ 2,026
Investment, Identifier [Axis]: I D I G Parent, L L C, Equity Securities, Common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			I D I G Parent, L L C [ Member]		I D I G Parent, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 324
Fair value at the ending			$ 287		$ 324
Number of shares held					245,958
Number of units held			245,958
Investment, Identifier [Axis]: I N H Buyer, Inc., Senior Secured Loans, due 6/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:INHBuyerInc.Member		mrcc:INHBuyerInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,832
Fair value at the ending			$ 2,925		$ 2,832
Investment, Identifier [Axis]: In Mobi Pte, Ltd, Media: Equity Securities, due 9/18/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:InMobiPteLtdMember		mrcc:InMobiPteLtdMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,816
Fair value at the ending			$ 1,965		$ 1,816
Warrants to purchase percentage of equity			2.80%		2.80%
Investment, Identifier [Axis]: Independence Buyer, Inc, Senior Secured Loans, due 8/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:IndependenceBuyerInc.Member		mrcc:IndependenceBuyerInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,866
Fair value at the ending			$ 5,417		$ 5,866
Investment, Identifier [Axis]: Independence Buyer, Inc. ( Revolver), Senior Secured Loans, due 8/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:IndependenceBuyerInc.Member		mrcc:IndependenceBuyerInc.Member
Investment, Identifier [Axis]: Independence Buyer, Inc., Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:IndependenceBuyerInc.Member		mrcc:IndependenceBuyerInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 102
Fair value at the ending			$ 68		$ 102
Number of units held			81		81
Investment, Identifier [Axis]: Intermedia Holdings, Inc., Senior Secured Loans, due 7/21/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: J2 B W A Funding L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:J2BWAFundingLLCMember		mrcc:J2BWAFundingLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 27
Investment, Identifier [Axis]: J2 BWA Funding LLC (Delayed Draw), Senior Notes, Due 12/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:J2BWAFundingLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,298
Fair value at the ending					$ 1,298
Investment, Identifier [Axis]: J2 Bwa Funding Llc Revolver Senior Notes Due 12/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:J2BWAFundingLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,550
Investment, Identifier [Axis]: KL Moon Acquisition LLC Common Units
Transactions with Affiliated Companies, Fair value Roll Forward
Number of units held			0.1
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Revolver) Senior Secured Loans Due
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KlMoonAcquisitionLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 244
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) Senior Secured Loans Due 2/1/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KlMoonAcquisitionLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 4,988
Investment, Identifier [Axis]: KL Moon Acquisition, LLC (fka Spectrum Science Communications, LLC), Equity Securities, Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KlMoonAcquisitionLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 500
Investment, Identifier [Axis]: Kar Wash Holdings LLC Equity Securities Series A Preferred Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KarWashHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 11
Number of shares held			8,619
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,782
Fair value at the ending			$ 2,229		$ 1,782
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Revolver), Senior Secured Loans, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 303
Fair value at the ending					$ 303
Investment, Identifier [Axis]: Kar Wash Holdings, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 111
Fair value at the ending			$ 61		$ 111
Number of shares held			99,807
Number of units held					99,807
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, One, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,585
Fair value at the ending			$ 1,576		$ 1,585
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, Two, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,135
Fair value at the ending			$ 1,129		$ 1,135
Investment, Identifier [Axis]: Keystone Purchaser, L L C, Senior Secured Loans, due 5/7/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, One, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, Two, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember		mrcc:KingsleyGatePartnersLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 131
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Revolver), Senior Secured Loans, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember		mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, , Senior Secured Loans, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:KingsleyGatePartnersLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 588
Fair value at the ending					$ 588
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, One Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 591
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, Two, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KingsleyGatePartnersLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 190
Investment, Identifier [Axis]: Kl Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Delayed Draw) Senior Secured Loans Due
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:KlMoonAcquisitionLlcMember
Investment, Identifier [Axis]: L S C S Holdings, Inc., Senior Secured Loans, due 12/15/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: L V F Holdings, Inc. ( Revolver), Senior Secured Loans, due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LXJTIntermediateHoldingsIncMember		mrcc:LVFHoldingsIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 152
Fair value at the ending					$ 152
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, ( Delayed Draw) due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:LVFHoldingsIncMember
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, One, due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LVFHoldingsIncMember		mrcc:LVFHoldingsIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,437
Fair value at the ending			$ 1,433		$ 1,437
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, Two, due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LVFHoldingsIncMember		mrcc:LVFHoldingsIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,375
Fair value at the ending			$ 1,372		$ 1,375
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc. ( Revolver), Senior Secured Loans, due 3/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LXJTIntermediateHoldingsIncMember		mrcc:LXJTIntermediateHoldingsIncMember
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc., Senior Secured Loans, due 3/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LXJTIntermediateHoldingsIncMember		mrcc:LXJTIntermediateHoldingsIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,394
Fair value at the ending			$ 5,366		$ 5,394
Investment, Identifier [Axis]: Laseraway Intermediate Holdings I I, L L C, Senior Secured Loans, due 10/14/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 8/2/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:LiftedTrucksHoldingsLLCMember
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Revolver), Senior Secured Loans, due 8/2/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftedTrucksHoldingsLLCMember		mrcc:LiftedTrucksHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 544
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftedTrucksHoldingsLLCMember		mrcc:LiftedTrucksHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 78
Fair value at the ending			$ 74		$ 78
Number of shares held			111,111
Number of units held					111,111
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Senior Secured Loans, due 8/2/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftedTrucksHoldingsLLCMember		mrcc:LiftedTrucksHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 6,840
Fair value at the ending			$ 6,740		$ 6,840
Investment, Identifier [Axis]: Liftforward SPV II LLC Senior Secured Loans Due 9/29/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:LiftforwardSPVIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 223
Investment, Identifier [Axis]: Liftforward SPV II, LLC, Senior Secured Loans, due 3/31/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:LiftforwardSPVIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			403
Fair value at the ending					$ 403
Investment, Identifier [Axis]: Lightbox Intermediate, L. P., Senior Secured Loans, due 5/11/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Luxury Optical Holdings Co., Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:LuxuryOpticalHoldingsCo.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 209
Fair value at the ending					$ 209
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C ( Delayed Draw), Senior Secured Loans Due 1/26/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember		mrcc:MCAssetManagementCorporateLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 850	$ 1,000	850	$ 850
PIK Interest (cost)				107
Fair value at the ending			$ 2,903	957	$ 1,000
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securites
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCAssetManagementCorporateLLCMember		mrcc:MCAssetManagementCorporateLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,291
Fair value at the ending			$ 1,232		$ 1,291
Percentage of equity interest					15.90%
Percentage of units held			15.90%
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 644	$ 1,291	644	$ 644
Net unrealized gain (loss)			(59)	107
Fair value at the ending			$ 1,232	$ 751	$ 1,291
Percentage of equity interest			15.90%	15.90%
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Senior Secured Loans Due 1/26/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:HFZCapitalGroupLLCMember	mrcc:MCAssetManagementCorporateLLCMember		mrcc:MCAssetManagementCorporateLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 7,154	$ 8,421	$ 7,154	$ 7,154
PIK Interest (cost)			1,311	903
Fair value at the ending			$ 9,732	8,057	$ 8,421
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C ( Revolver), Senior Secured Loans, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C , Equity Securities, Class A-2 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 204
Fair value at the ending			$ 432		$ 204
Number of units held			118,906		118,906
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, One, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 9,736
Fair value at the ending			$ 973		$ 9,736
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, Two, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,977
Fair value at the ending			$ 2,957		$ 2,977
Investment, Identifier [Axis]: M R C C Senior Loan Fund I, L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Controlled affiliate company investments		Controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			MRCC Senior Loan Fund I, LLC		MRCC Senior Loan Fund I, LLC
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 41,125	$ 35,509	41,125	$ 41,125
Purchases (cost)				500
Net unrealized gain (loss)			(2,240)	(5,081)
Fair value at the ending			$ 33,269	36,544	$ 35,509
Percentage of equity interest			50%		50%
Investment, Identifier [Axis]: M V Receivables I I, L L C ( Delayed Draw), Senior Secured Loans, due 7/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MVReceivablesIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 7,968
Fair value at the ending					$ 7,968
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MVReceivablesIILLCMember		mrcc:MVReceivablesIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,154
Fair value at the ending					$ 1,154
Warrants to purchase percentage of equity					0.80%
Number of units held			1,458		1,458
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Due 7/28/2031, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MVReceivablesIILLCMember		mrcc:MVReceivablesIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,655
Fair value at the ending					$ 1,655
Warrants to purchase percentage of equity			0.80%
Investment, Identifier [Axis]: M V Receivables I I, L L C, Senior Secured Loans, due 7/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MVReceivablesIILLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 8,017
Investment, Identifier [Axis]: MC Asset Management (Corporate), LLC, Senior Secured Loans, Two, Due 1/26/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCAssetManagementCorporateLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,000
Purchases (cost)			1,586
PIK Interest (cost)			317
Fair value at the ending			$ 2,903		$ 1,000
Investment, Identifier [Axis]: MCP Shaw Acquisitionco, LLC, Senior Secured Loans, Three, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 979
Fair value at the ending			$ 9,624		$ 979
Investment, Identifier [Axis]: MEI Buyer LLC (Delayed Draw), Senior Secured Loans, due 6/29/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MeiBuyerLlcMember
Investment, Identifier [Axis]: MEI Buyer LLC (Revolver), Senior Secured Loans, due 6/29/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MeiBuyerLlcMember
Investment, Identifier [Axis]: MEI Buyer LLC, Equity Securities, Common Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MeiBuyerLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 138
Number of shares held			155
Investment, Identifier [Axis]: MEI Buyer LLC, Senior Secured Loans, due 6/29/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MeiBuyerLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2,015
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Delayed Draw), Senior Secured Loans, due 1/7/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Revolver), Senior Secured Loans, due 1/7/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C, Senior Secured Loans, due 1/7/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mammoth Holdings, LLC (Revolver), Senior Secured Loans, Due, 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember		mrcc:MammothHoldingsLLCMember
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MammothHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 13,728
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Four, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MammothHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,630
Fair value at the ending					$ 1,630
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, One, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MammothHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,917
Fair value at the ending					$ 1,917
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Three, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MammothHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			6,282
Fair value at the ending					$ 6,282
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Two, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MammothHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			4,025
Fair value at the ending					$ 4,025
Investment, Identifier [Axis]: Mark Logic Corporation ( Revolver), Senior Secured Loans, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MarkLogicCorporationMember
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Four, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MarkLogicCorporationMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			213
Fair value at the ending					$ 213
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, One, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MarkLogicCorporationMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			3,414
Fair value at the ending					$ 3,414
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Three, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MarkLogicCorporationMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			2,656
Fair value at the ending					$ 2,656
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Two, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MarkLogicCorporationMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			318
Fair value at the ending					$ 318
Investment, Identifier [Axis]: MarkLogic Corporation, Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MarkLogicCorporationMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 426
Fair value at the ending					$ 426
Number of units held					290,239
Investment, Identifier [Axis]: Mavenir Systems, Inc., Senior Secured Loans, due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mc Kissock Investment Holdings, L L C, Senior Secured Loans, due 3/9/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Medallia, Inc, Senior Secured Loans, due 10/27/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MedalliaIncMember		mrcc:MedalliaIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,041
Fair value at the ending			$ 2,150		$ 2,041
Investment, Identifier [Axis]: Mindbody, Inc. ( Revolver) (f), Senior Secured Loans, due 2/14/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MindbodyIncMember		mrcc:MedalliaIncMember
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, One, due 2/14/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MindbodyIncMember		mrcc:MedalliaIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 6,526
Fair value at the ending			$ 6,526		$ 6,526
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, Two, due 2/14/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MindbodyIncMember		mrcc:MedalliaIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 673
Fair value at the ending			$ 473		$ 673
Investment, Identifier [Axis]: Minotaur Acquisition, Inc., Senior Secured Loans, due 3/27/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, One 12/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 6,059
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, Two 12/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 53
Investment, Identifier [Axis]: Mnine Holdings, Inc (Revolver), Senior Secured Loans, Due 12/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 533
Investment, Identifier [Axis]: Mnine Holdings, Inc, Senior Secured Loans, Due 12/30/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,492
Fair value at the ending					$ 5,492
Investment, Identifier [Axis]: Mnine Holdings, Inc. (Revolver), Senior Secured Loans, due 12/30/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]		Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 214
Purchases (cost)			308	240
PIK Interest (cost)			11
Fair value at the ending			$ 533	$ 240	$ 214
Investment, Identifier [Axis]: Mnine Holdings, Inc., Equity Securities, Class B units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]		Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Number of units held			6,400	6,400	6,400
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due 12/30/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 5,771		$ 5,771	$ 5,771
Purchases (cost)			$ 105
Sales and paydowns (cost)			(52)
PIK Interest (cost)				230
Discount accretion				12
Net unrealized gain (loss)				(12)
Fair value at the ending			$ 53	6,001
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due Two 12/30/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,492
PIK Interest (cost)			569
Discount accretion			12
Net unrealized gain (loss)			(14)
Fair value at the ending			$ 6,059		$ 5,492
Investment, Identifier [Axis]: Money Lion, Inc. ( Delayed Draw), Junior Secured Loans, due 3/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MoneyLionIncMember
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 10/16/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MoneyLionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 379
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 3/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MoneyLionIncMember		mrcc:MoneyLionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,165
Fair value at the ending			5,275		$ 5,165
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 5/1/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MoneyLionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,498
Fair value at the ending					$ 1,498
Investment, Identifier [Axis]: N C B P Property, L L C, Senior Secured Loans, due 12/16/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:NCBPPropertyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,955
Fair value at the ending					$ 1,955
Investment, Identifier [Axis]: N E C B Collections, L L C ( Revolver), Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			N E C B Collections, L L C [ Member]		N E C B Collections, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 632	$ 382	632	$ 632
Net unrealized gain (loss)			42	(206)
Fair value at the ending			$ 424	$ 426	$ 382
Investment, Identifier [Axis]: N E C B Collections, L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]		N E C B Collections, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Percentage of units held			20.80%	20.80%	20.80%
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Delayed Draw), Senior Secured Loans, Due 10/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Revolver), Senior Secured Loans, Due 10/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Equity Securities, Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 327
Fair value at the ending			$ 370		$ 327
Number of units held			327,133		327,133
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Senior Secured Loans, Due 10/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,430
Fair value at the ending			$ 3,508		$ 3,430
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, One, Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,039
Fair value at the ending			$ 3,962		$ 4,039
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, Two, Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,813
Fair value at the ending			$ 4,721		$ 4,813
Investment, Identifier [Axis]: Nations Benefits LLC Delayed Draw, Senior Secured Loans Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 961
Fair value at the ending			$ 5,119		$ 961
Investment, Identifier [Axis]: Nations Benefits, L L C (Revolver), Senior Secured Loans, Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 889
Fair value at the ending			$ 889		$ 889
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, One, Series B units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 934
Fair value at the ending			$ 730		$ 934
Number of units held			116,460		116,460
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, Two, common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 66
Fair value at the ending					$ 66
Number of units held			106,667		106,667
Investment, Identifier [Axis]: Natus Medical Incorporated, Senior Secured Loans, due 7/20/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Nearly Natural Inc. Senior Secured Loans One due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 6,134
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Four, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,731
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Three, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2,890
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Two, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,589
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, One, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember		mrcc:NearlyNaturalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Number of units held			152,174		152,174
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, Two, Class A A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalIncMember		mrcc:NearlyNaturalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2
Number of units held			61,087		61,087
Investment, Identifier [Axis]: Nearly Natural, Inc. (Revolver), Senior Secured Loans, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NearlyNaturalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2,444
Investment, Identifier [Axis]: Nearly Natural, Inc.( Revolver), Senior Secured loans, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:NearlyNaturalIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			2,241
Fair value at the ending					$ 2,241
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Four, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:NearlyNaturalIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,672
Fair value at the ending					$ 1,672
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, One, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:NearlyNaturalIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			5,931
Fair value at the ending					$ 5,931
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Three, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:NearlyNaturalIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			2,787
Fair value at the ending					$ 2,787
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Two, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:NearlyNaturalIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,534
Fair value at the ending					$ 1,534
Investment, Identifier [Axis]: Newforma, Inc. ( Revolver) (f), Senior Secured Loans, due 3/31/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MedalliaIncMember
Investment, Identifier [Axis]: Newforma, Inc., Senior Secured Loans, due 3/31/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:MedalliaIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 938
Fair value at the ending					$ 938
Investment, Identifier [Axis]: North Haven Spartan U S Holdco, L L C, Senior Secured Loans, due 6/6/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Delayed Draw), Senior Secured Loans, due, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Revolver), Senior Secured Loans, due, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 187
Fair value at the ending			$ 409		$ 187
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, One, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,448
Fair value at the ending			$ 2,390		$ 2,448
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, Two, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,575
Fair value at the ending			$ 2,518		$ 2,575
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Four, due 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,433
Fair value at the ending			$ 1,399		$ 1,433
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Three, due 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 709
Fair value at the ending			692		$ 709
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, One, due 6/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:OceanaAustralianFixedIncomeTrustMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			3,084
Fair value at the ending					$ 3,084
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, Two, due 2/25/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:OceanaAustralianFixedIncomeTrustMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 7,321
Fair value at the ending					$ 7,321
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, One, due 6/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, Two, due 6/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Onit, Inc., Unitranche Secured Loans, due 5/2/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:OnitInc.Member		mrcc:OnitInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,663
Fair value at the ending			$ 1,680		$ 1,663
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, One, due 10/21/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Three, due 10/21/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Two, due 10/21/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Output Services Group Inc. Senior Secured Loans Due 6/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P H Beauty Holdings I I I, I N C., Senior Secured Loans, due 9/26/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Four, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 46
Fair value at the ending			$ 42		$ 46
Number of shares held			916
Number of units held					916
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, One, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 298
Fair value at the ending			$ 268		$ 298
Number of shares held			5,680
Number of units held					5,680
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Three, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 7
Fair value at the ending			$ 6		$ 7
Number of shares held			132
Number of units held					132
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Two, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 46
Fair value at the ending			$ 41		$ 46
Number of shares held			5,714
Number of units held					5,714
Investment, Identifier [Axis]: P V H C Holding Corp, Senior Secured Loans, due 2/17/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Panda Acquisition, LLC, Senior Secured Loans, due 10/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PandaAcquisitionLlcMember		mrcc:PandaAcquisitionLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,690
Fair value at the ending			$ 3,720		$ 3,690
Investment, Identifier [Axis]: Paragon Healthcare Inc. Senior Secured Loan Due 1/19/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Delayed Draw Senior Secured Loans due 1/19/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Revolver Senior Secured Loan Due 1/19/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group), Senior Secured Loan due 8/2/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Five, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PlanfulInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 708
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Four, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 878
Fair value at the ending			$ 884		$ 878
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 9,443
Fair value at the ending			$ 9,500		$ 9,443
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 19
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Three, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,318
Fair value at the ending			$ 1,326		$ 1,318
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Two, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 527
Fair value at the ending			$ 530		$ 527
Investment, Identifier [Axis]: Planful, Inc. ( Revolver), Senior Secured Loans, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 439
Fair value at the ending			$ 442		$ 439
Investment, Identifier [Axis]: Planful, Inc., Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PlanfulInc.Member		mrcc:PlanfulInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 563
Fair value at the ending			$ 860		$ 563
Number of units held			473,082		473,082
Investment, Identifier [Axis]: Planful, Inc., Equity Securities, Class B Units
Transactions with Affiliated Companies, Fair value Roll Forward
Number of shares held			35,791
Investment, Identifier [Axis]: Polychem Acquisition, L L C, Senior Secured Loans, due 3/17/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Prototek LLC (Delayed Draw), Senior Secured Loans, Due 12/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PrototekLlcMember		mrcc:PrototekLlcMember
Investment, Identifier [Axis]: Prototek LLC (Revolver), Senior Secured Loans, Due 12/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PrototekLlcMember		mrcc:PrototekLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 90
Investment, Identifier [Axis]: Prototek LLC, Senior Secured Loans, Due 12/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:PrototekLlcMember		mrcc:PrototekLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,425
Fair value at the ending			2,432		$ 2,425
Investment, Identifier [Axis]: Quest Resource Management Group, L L C ( Delayed Draw), Senior Secured Loans, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:QuestResourceManagementGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 381
Fair value at the ending					$ 381
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securites, Two, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 147
Fair value at the ending			$ 185		$ 147
Warrants to purchase percentage of equity			0.20%		0.20%
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securities, One, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 210
Fair value at the ending			$ 264		$ 210
Warrants to purchase percentage of equity			0.20%		0.20%
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, One, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 972
Fair value at the ending			$ 854		$ 972
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Three, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,781
Fair value at the ending			$ 3,319		$ 3,781
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Two, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,067
Fair value at the ending			$ 938		$ 1,067
Investment, Identifier [Axis]: Quest Resource Management Group, LLC, Senior Secured Loans, Four, Due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:QuestResourceManagementGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 335
Investment, Identifier [Axis]: Radiology Partners, Inc., Senior Secured Loans, due 7/9/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Recorded Future, Inc, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Recorded Future, Inc [ Member]		Recorded Future, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 225
Fair value at the ending			$ 281		$ 225
Number of units held			80,486		80,486
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C ( Revolver), Senior Secured Loans, due 8/4/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RecycledPlasticsIndustriesLLCMember		mrcc:RecycledPlasticsIndustriesLLCMember
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C, Senior Secured Loans, due 8/4/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RecycledPlasticsIndustriesLLCMember		mrcc:RecycledPlasticsIndustriesLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,370
Fair value at the ending			$ 3,254		$ 3,370
Investment, Identifier [Axis]: Relativity O D A L L C ( Revolver), Senior Secured Loans, due 5/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelativityODALLCMember		mrcc:RelativityODALLCMember
Investment, Identifier [Axis]: Relativity O D A L L C, Senior Secured Loans, due 5/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelativityODALLCMember		mrcc:RelativityODALLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,060
Fair value at the ending			2,110		$ 2,060
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Delayed Draw), Senior Secured Loans, due, 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:RelevateHealthGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 648
Fair value at the ending					$ 648
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Revolver), Senior Secured Loans, due, 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, Class B common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Number of units held			40		40
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 36
Fair value at the ending			$ 39		$ 36
Number of units held			40		40
Investment, Identifier [Axis]: Relevate Health Group, L L C, Senior Secured Loans, due, 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,449
Fair value at the ending			$ 652		$ 1,449
Investment, Identifier [Axis]: Relevate Health Group, LLC, Senior Secured Loans, Two, Due 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RelevateHealthGroupLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,458
Investment, Identifier [Axis]: Research Now Group, Inc. and Survey Sampling International, L L C, Senior Secured Loans, due 12/20/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Rockdale Blackhawk, L L C, Senior Secured Loans, no stated maturity
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:RockdaleBlackhawkLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 557
Fair value at the ending					$ 557
Investment, Identifier [Axis]: Rockdale Blackhawk, LLC, Senior Secured Loans, due, 11/30/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:RockdaleBlackhawkLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 527
Investment, Identifier [Axis]: Runner Buyer I N C., Senior Secured Loans, due 10/23/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S F R Holdco, L L C Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		S F R Holdco, L L C [ Member]	S F R Holdco, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 3,900		$ 3,900	3,900
Fair value at the ending				3,900
Percentage of equity interest			24.40%
Investment, Identifier [Axis]: S F R Holdco, L L C, Junior Secured Loans Due 7/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			S F R Holdco, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		5,850	$ 5,850	5,850	5,850
Net unrealized gain (loss)			508
Fair value at the ending			$ 6,358	$ 5,850	$ 5,850
Investment, Identifier [Axis]: S I R V A Worldwide Inc., Senior Secured Loans, due 8/4/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S T A T S Intermediate Holdings, L L C, Senior Secured Loans, due 7/10/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S W Ingredients Holdings, L L C, Senior Secured Loans, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: SFR Holdco, LLC, Equity Securities, 24.4% of Interest
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			S F R Holdco, L L C [ Member]		mrcc:SfrHoldcoLlcEquitySecurities24.4OfInterestMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,900
Net unrealized gain (loss)			339
Fair value at the ending			$ 4,239		$ 3,900
Percentage of equity interest					24.40%
Percentage of units held			24.40%	24.40%
Investment, Identifier [Axis]: Sandvine Corporation, Senior Secured Loans, due 10/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C ( Revolver), Senior Secured Loans, Due 8/9/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Second Avenue S F R Holdings I I L L C [ Member]		Second Avenue S F R Holdings I I L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 2,104	$ 4,755	$ 2,104	$ 2,104
Purchases (cost)				2,681
Net unrealized gain (loss)			6	(18)
Fair value at the ending			4,761	4,767	$ 4,755
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C, Junior Secured Loans, Due 7/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					Second Avenue S F R Holdings I I L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 5,850
Fair value at the ending					$ 5,850
Investment, Identifier [Axis]: Secretariat Advisors L L C, Senior Secured Loans, due 12/29/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Secretariat Advisors LLC, Senior Secured Loans, Two, due 12/29/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Five, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,532
Fair value at the ending			$ 1,524		$ 1,532
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Four, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,131
Fair value at the ending			$ 2,119		$ 2,131
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, One, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,372
Fair value at the ending			$ 3,353		$ 3,372
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Three, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 7,884
Fair value at the ending			$ 7,840		$ 7,884
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Two, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,425
Fair value at the ending			$ 2,412		$ 2,425
Investment, Identifier [Axis]: Seran Bio Science, L L C ( Revolver), Senior Secured Loans, due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Investment, Identifier [Axis]: Seran Bio Science, L L C, Equity Securities, common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 537
Fair value at the ending			$ 737		$ 537
Number of units held			33,333		33,333
Investment, Identifier [Axis]: Seran Bio Science, L L C, Senior Secured Loans, due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,435
Fair value at the ending			$ 2,425		$ 2,435
Investment, Identifier [Axis]: Seran BioScience, LLC (Delayed Draw), Senior Secured Loans, Due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,320
Fair value at the ending			$ 2,527		$ 1,320
Investment, Identifier [Axis]: Seran Bioscience Llc (Delayed Draw) One Senior Secured Loans Due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SeranBioScienceLLCMember
Investment, Identifier [Axis]: Service Max, Inc. ( Revolver) , Senior Secured Loans, due 11/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ServiceMaxIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 175
Fair value at the ending					$ 175
Investment, Identifier [Axis]: Service Max, Inc., Senior Secured Loans, due 11/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ServiceMaxIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,884
Fair value at the ending					$ 3,884
Investment, Identifier [Axis]: Sparq Holdings Inc. Delayed Draw Senior Secured Loans Due 6/15/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SparqHoldingsInc.Member
Investment, Identifier [Axis]: Sparq Holdings Inc. Revolver Senior Secured Loans Due 6/15/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SparqHoldingsInc.Member
Investment, Identifier [Axis]: Sparq Holdings Inc. Senior Secured Loans Due 6/15/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SparqHoldingsInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 998
Investment, Identifier [Axis]: Sparq Holdings, Inc. Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SparqHoldingsInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 305
Number of shares held			300,000
Investment, Identifier [Axis]: Spectrum Science Communications, L L C ( Revolver), Senior Secured Loans, due 1/25/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:SpectrumScienceCommunicationsLLCMember
Investment, Identifier [Axis]: Spectrum Science Communications, L L C, Senior Secured Loans, due 1/25/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:SpectrumScienceCommunicationsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,005
Fair value at the ending					$ 1,005
Investment, Identifier [Axis]: Spherix Global Inc, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SpherixGlobalIncMember		mrcc:SpherixGlobalInc.Member
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 63
Fair value at the ending			$ 54		$ 63
Number of units held			81		81
Investment, Identifier [Axis]: Spherix Global Inc. ( Revolver), Senior Secured Loans, due, 12/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SpherixGlobalInc.Member		mrcc:SpherixGlobalIncMember
Investment, Identifier [Axis]: Spherix Global Inc. , Senior Secured Loans, due, 12/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SpherixGlobalInc.Member		mrcc:SpherixGlobalIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,088
Fair value at the ending			$ 1,058		$ 1,088
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Delayed Draw), Due 11/3/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SportsOperatingHoldingsIiLlcMember		mrcc:SportsOperatingHoldingsIiLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 243
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Revolver), Due, 11/3/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SportsOperatingHoldingsIiLlcMember		mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC, Due, 11/3/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:SportsOperatingHoldingsIiLlcMember		mrcc:SportsOperatingHoldingsIiLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,918
Fair value at the ending			$ 2,985		$ 2,918
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, ( Revolver), Senior Secured Loans, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:StarComplianceMidCoLLCMember		mrcc:StarComplianceMidCoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 79
Fair value at the ending			$ 189		$ 79
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, One, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:StarComplianceMidCoLLCMember		mrcc:StarComplianceMidCoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,968
Fair value at the ending			$ 1,988		$ 1,968
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Three, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:StarComplianceMidCoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 255
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Two, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:StarComplianceMidCoLLCMember		mrcc:StarComplianceMidCoLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 330
Fair value at the ending			$ 333		$ 330
Investment, Identifier [Axis]: T A T T Buyer, L L C, Senior Secured Loans, due 3/30/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, One, due 4/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TCFIIIOWLBuyerLLCMember		mrcc:TCFIIIOWLBuyerLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,022
Fair value at the ending			$ 2,004		$ 2,022
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Three, due 4/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TCFIIIOWLBuyerLLCMember		mrcc:TCFIIIOWLBuyerLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,215
Fair value at the ending			$ 2,196		$ 2,215
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Two, due 4/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TCFIIIOWLBuyerLLCMember		mrcc:TCFIIIOWLBuyerLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,469
Fair value at the ending			$ 2,447		$ 2,469
Investment, Identifier [Axis]: T E A M Public Choices, L L C, Senior Secured Loans, due 12/17/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T G G T S Acquisition Company, Senior Secured Loans, due 12/12/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J C Spartech Acquisition Corp., Senior Secured Loans, due 5/5/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J Management Hold Co L L C ( Revolver), Senior Secured Loans, Due 6/28/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			T J Management Hold Co L L C [ Member]		T J Management Hold Co L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 80
Purchases (cost)				80
Fair value at the ending			$ 80	80	$ 80
Investment, Identifier [Axis]: T J Management Hold Co L L C, Equity Securities, Common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]		T J Management Hold Co L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 3,148	$ 2,766	3,148	$ 3,148
Net unrealized gain (loss)			417	(407)
Fair value at the ending			$ 3,183	$ 2,741	$ 2,766
Number of shares held			16	16
Investment, Identifier [Axis]: TJ Management HoldCo LLC, Equity Securities, due 9/9/2020
Transactions with Affiliated Companies, Fair value Roll Forward
Number of shares held					16
Investment, Identifier [Axis]: Tait L L C ( Revolver), Senior Secured Loans, due 3/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Tait L L C, Senior Secured Loans, due 3/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Teneo Holdings L L C, Senior Secured Loans, due 7/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Cook & Boardman Group L L C, Senior Secured Loans, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kleinfelder Group, Inc., Senior Secured Loans, due 11/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kyjen Company, L L C ( Revolver), Senior Secured Loans, due 4/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TheKyjenCompanyLLCMember		mrcc:TheKyjenCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 88
Fair value at the ending					$ 88
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior SEcured Loans, Two, Due 4/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TheKyjenCompanyLLCMember		mrcc:TheKyjenCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior Secured Loans, due 4/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TheKyjenCompanyLLCMember		mrcc:TheKyjenCompanyLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 975
Fair value at the ending			$ 979		$ 975
Investment, Identifier [Axis]: Thrasio, L L C, Senior Secured Loans, due 12/18/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ThrasioLLCMember		mrcc:ThrasioLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,445
Fair value at the ending			$ 2,043		$ 2,445
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Delayed Draw), Senior Secured Loans, due 2/16/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TigerConnectIncMember		mrcc:TigerConnectIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 27
Fair value at the ending			$ 106		$ 27
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Revolver), Senior Secured Loans, due 2/16/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TigerConnectIncMember		mrcc:TigerConnectIncMember
Investment, Identifier [Axis]: Tiger Connect, Inc., Senior Secured Loans, due 2/16/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:TigerConnectIncMember		mrcc:TigerConnectIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,963
Fair value at the ending			$ 2,940		$ 2,963
Investment, Identifier [Axis]: Trident Maritime Systems, Inc ( Revolver), Senior Secured Loans, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, One, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, Two, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, One, due 12/14/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, Two, due 12/14/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck-Lite Co., LLC, Senior Secured Loans, Three, due 12/14/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: V B E1, L L C ( Delayed Draw), Unitranche Secured Loans, due 11/18/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VBE1LLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 2,250
Investment, Identifier [Axis]: V B E1, L L C, Unitranche Secured Loans, due 11/18/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:VBE1LLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,257
Fair value at the ending					$ 2,257
Investment, Identifier [Axis]: V P S Holdings, L L C ( Revolver), Senior Secured Loans, due 10/4/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VPSHoldingsLLCMember		mrcc:VPSHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 102
Fair value at the ending			$ 703		$ 102
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, One, due 10/4/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VPSHoldingsLLCMember		mrcc:VPSHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,252
Fair value at the ending			$ 2,570		$ 3,252
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, Two, due 10/4/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VPSHoldingsLLCMember		mrcc:VPSHoldingsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,661
Fair value at the ending			$ 2,112		$ 2,661
Investment, Identifier [Axis]: V10 Entertainment, Inc, Equity Securities, Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			V10 Entertainment, Inc. [Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 185
Number of shares held			392,157
Investment, Identifier [Axis]: V10 Entertainment, Inc. (Revolver), Senior Secured Loans, Due 1/12/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			V10 Entertainment, Inc. [Member]
Investment, Identifier [Axis]: V10 Entertainment, Inc., Senior Secured Loans, Due 1/12/2028
Transactions with Affiliated Companies
Investment, Issuer Name [Extensible Enumeration]			V10 Entertainment, Inc. [Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 4,016
Investment, Identifier [Axis]: Valudor Products L L C ( Revolver), Senior Secured Loans, due 6/19/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 55
Fair value at the ending					$ 55
Investment, Identifier [Axis]: Valudor Products L L C , Equity Securities, Class A-1 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember		mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 555
Fair value at the ending			$ 402		$ 555
Number of units held			501,014		501,014
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, One, due 6/19/2023,
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,958
Fair value at the ending					$ 1,958
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Three, due 6/19/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,565
Fair value at the ending					$ 1,565
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Two, due 6/19/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 312
Fair value at the ending					$ 312
Investment, Identifier [Axis]: Valudor Products LLC (Revolver), Senior Secured Loans, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, One, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,895
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Three, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,423
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Two, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ValudorProductsLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 276
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Delayed Draw), Senior Secured Loans, due 6/8/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VhagarPurchaserLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 150
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Revolver), Senior Secured Loans, due, 6/8/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VhagarPurchaserLlcMember
Investment, Identifier [Axis]: Vhagar Purchaser, LLC, Senior Secured Loans, due 6/8/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:VhagarPurchaserLlcMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 3,000
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,342
Number of units held			1,480,000
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Five, due 1/31/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 463
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Four, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, One, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Three, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Two, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, One, due 1/31/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 196
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Three, due 1/31/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 648
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Two, due 12/12/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:ViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 114
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Four, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			196
Fair value at the ending					$ 196
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, One, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			1,657
Fair value at the ending					$ 1,657
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Three, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			520
Fair value at the ending					$ 520
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Two, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:ViceGroupHoldingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 318
Fair value at the ending					$ 318
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Four, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, One, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Three, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Two, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: W3 Monroe R E Debt L L C, Senior Secured Loans, due 2/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:W3MonroeREDebtLLCMember		mrcc:W3MonroeREDebtLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 3,210
Fair value at the ending			$ 3,437		$ 3,210
Investment, Identifier [Axis]: W3 Monroe RE Debt LLC (Delayed Draw), Senior Secured Loans, Due 2/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:W3MonroeREDebtLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 80
Investment, Identifier [Axis]: Wheel Pros, Inc., Senior Secured Loans, due 5/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Delayed Draw), Senior Secured Loans, due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:WhistlerParentHoldingsIIIIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 56
Fair value at the ending					$ 56
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Revolver), Senior Secured Loans, due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WhistlerParentHoldingsIIIIncMember		mrcc:WhistlerParentHoldingsIIIIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 84
Fair value at the ending			$ 557		$ 84
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc., Senior Secured Loans, due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WhistlerParentHoldingsIIIIncMember		mrcc:WhistlerParentHoldingsIIIIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 4,457
Fair value at the ending			$ 4,457		$ 4,457
Investment, Identifier [Axis]: Whistler Parent Holdings III Inc. One Senior Secured Loans due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WhistlerParentHoldingsIIIIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 56
Investment, Identifier [Axis]: WillowTree, LLC, Unitranche Secured Loans, due 10/9/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:WillowTreeLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 7,326
Fair value at the ending					$ 7,326
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C ( Delayed Draw), Junior Secured Loans, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WitkoffMonroe700JVLLCMember		mrcc:WitkoffMonroe700JVLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 6,014
Fair value at the ending			$ 603		$ 6,014
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Equity Securities, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WitkoffMonroe700JVLLCMember		mrcc:WitkoffMonroe700JVLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,047
Fair value at the ending			$ 1,806		$ 1,047
Number of units held			2,141		2,141
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, One, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WitkoffMonroe700JVLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 6,716
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, Two, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:WitkoffMonroe700JVLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,162
Investment, Identifier [Axis]: Xan Edu Publishing, Inc, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:XanEduPublishingIncMember		mrcc:XanEduPublishingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 223
Fair value at the ending			$ 243		$ 223
Number of units held			49,479		49,479
Investment, Identifier [Axis]: Xan Edu Publishing, Inc. ( Revolver), Senior Secured Loans, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:XanEduPublishingIncMember		mrcc:XanEduPublishingIncMember
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, One, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:XanEduPublishingIncMember		mrcc:XanEduPublishingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,829
Fair value at the ending			$ 4,549		$ 1,829
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, Two, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:XanEduPublishingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the ending			$ 1,812
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:XanEduPublishingIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			4,602
Fair value at the ending					$ 4,602
Investment, Identifier [Axis]: Y S W H 4, L L C (Revolver), Senior Secured Loans, Due 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]					Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]					mrcc:YSWH4LLCRevolverMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 1,776
Fair value at the ending					$ 1,776
Investment, Identifier [Axis]: iCIMS, Inc., Senior Secured Loans, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:IcimsIncMember		mrcc:IcimsIncMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning			$ 2,456
Fair value at the ending			2,500		$ 2,456
Non-controlled affiliate company investments
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 90,281	86,618	$ 90,281	90,281
Purchases (cost)			2,121	3,276
Sales and paydowns (cost)			(6,227)	(5,247)
PIK Interest (cost)			4,953	2,419
Discount accretion			28	31
Net realized gain (loss)				(1)
Net unrealized gain (loss)			(2,595)	(5,485)
Fair value at the ending			84,898	85,274	86,618
Non-controlled affiliate company investments | American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 23,748	19,546	23,748	23,748
PIK Interest (cost)			2,745	1,179
Net unrealized gain (loss)			(4,271)	(5,251)
Fair value at the ending			18,020	19,676	19,546
Non-controlled affiliate company investments | Ascent Midco, L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Ascent Midco, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 8,946	8,186	8,946	8,946
Sales and paydowns (cost)			(6,175)	(130)
Discount accretion			16	19
Net unrealized gain (loss)			(113)	(1,257)
Fair value at the ending			1,914	7,578	8,186
Non-controlled affiliate company investments | C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 5,111	146	5,111	5,111
Purchases (cost)				92
Sales and paydowns (cost)				(5,117)
Net realized gain (loss)				(1)
Net unrealized gain (loss)			(146)	61
Fair value at the ending				146	146
Non-controlled affiliate company investments | Familia Dental Group Holdings, LLC
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Familia Dental Group Holdings, LLC
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 1,919	2,625	1,919	1,919
Purchases (cost)			122	183
Net unrealized gain (loss)			(396)	406
Fair value at the ending			2,351	2,508	2,625
Non-controlled affiliate company investments | H F Z Capital Group, L L C And M C Asset Management ( Corporate), L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		mrcc:MCAssetManagementCorporateLLCMember
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 29,152	32,676	29,152	29,152
Purchases (cost)			1,586
PIK Interest (cost)			1,628	1,010
Net unrealized gain (loss)			1,033	1,199
Fair value at the ending			36,923	31,361	32,676
Non-controlled affiliate company investments | Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 5,771	5,706	5,771	5,771
Purchases (cost)			413	240
Sales and paydowns (cost)			(52)
PIK Interest (cost)			580	230
Discount accretion			12	12
Net unrealized gain (loss)			(14)	(12)
Fair value at the ending			6,645	6,241	5,706
Non-controlled affiliate company investments | N E C B Collections, L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		N E C B Collections, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 632	382	632	632
Net unrealized gain (loss)			42	(206)
Fair value at the ending			424	426	382
Non-controlled affiliate company investments | Second Avenue S F R Holdings I I L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		Second Avenue S F R Holdings I I L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 2,104	4,755	2,104	2,104
Purchases (cost)				2,681
Net unrealized gain (loss)			6	(18)
Fair value at the ending			4,761	4,767	4,755
Non-controlled affiliate company investments | S F R Holdco, L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		S F R Holdco, L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 9,750	9,750	9,750	9,750
Net unrealized gain (loss)			847
Fair value at the ending			10,597	9,750	9,750
Non-controlled affiliate company investments | T J Management Hold Co L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		T J Management Hold Co L L C [ Member]
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 3,148	2,846	3,148	3,148
Purchases (cost)				80
Net unrealized gain (loss)			417	(407)
Fair value at the ending			3,263	2,821	2,846
Controlled affiliate company investments
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 41,125	35,509	41,125	41,125
Purchases (cost)				500
Net unrealized gain (loss)			(2,240)	(5,081)
Fair value at the ending			33,269	36,544	35,509
Controlled affiliate company investments | MRCC Senior Loan Fund I, LLC
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]		Controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]		MRCC Senior Loan Fund I, LLC
Transactions with Affiliated Companies, Fair value Roll Forward
Fair value at the beginning		$ 41,125	35,509	41,125	41,125
Purchases (cost)				500
Net unrealized gain (loss)			(2,240)	(5,081)
Fair value at the ending			$ 33,269	$ 36,544	$ 35,509

Transactions with Affiliated _4

Transactions with Affiliated Companies - Income Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Investment, Identifier [Axis]: 360 Holdco, Inc. ( Delayed Draw), Senior Secured Loans, due 8/2/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: 360 Holdco, Inc., Senior Secured Loans, due 8/2/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A P C O Worldwide, Inc, Equity Securities, Class A voting common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:APCOWorldwideIncMember		mrcc:APCOWorldwideIncMember
Investment, Identifier [Axis]: A Q Carver Buyer, Inc., Senior Secured Loans, due 9/23/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: A S G I I, L L C ( Delayed Draw), Unitranche Secured Loans, 5/25/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ASGIILLCMember		mrcc:ASGIILLCMember
Investment, Identifier [Axis]: A S G I I, L L C, Unitranche Secured Loans, due 5/25/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ASGIILLCMember		mrcc:ASGIILLCMember
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Delayed Draw), Senior Secured Loans, due 12/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C ( Revolver), Senior Secured Loans, due 12/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Accelerate Auto Works Intermediate, L L C, Senior Secured Loans, due 12/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Ad Theorent Holding Company, Inc. Equity Securities, common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AdTheorentHoldingCompanyIncMember		mrcc:AdTheorentHoldingCompanyIncMember
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 12/21/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AmeliaHoldingIiLlcDelayedDrawMember		mrcc:AmeliaHoldingIiLlcMember
Investment, Identifier [Axis]: Amelia Holding II, LLC (Delayed Draw), Due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ArcstorMidcoLLCMember
Investment, Identifier [Axis]: Amelia Holding II, LLC (Revolver), Due 12/21/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AmeliaHoldingIiLlcRevolverMember		mrcc:AmeliaHoldingIiLlcMember
Investment, Identifier [Axis]: Amelia Holding II, LLC, Due 12/21/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AmeliaHoldingIiLlcMember		mrcc:AmeliaHoldingIiLlcMember
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AmeliaHoldingIiLlcMember
Investment, Identifier [Axis]: Amelia Holding II, LLC, Equity Securities, Warrant
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:AmeliaHoldingIiLlcMember
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Delayed Draw), Senior Secured Loans, due 6/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C ( Revolver), Senior Secured Loans, due 6/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Identifier [Axis]: American Broadband and Telecommunications Company L L C, Equity Securities, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember		mrcc:AmericanBroadbandandTelecommunicationsCompanyLLCMember
Investment, Identifier [Axis]: American Community Homes, Inc. ( Revolver), Senior Secured Loans Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Interest income				$ 2	$ 19
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities Due 12/18/2024, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Equity Securities, Common Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Acquisition Date 3/29/2019
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Interest income				$ 480	362
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Five, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Acquisition Date 8/10/2018
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Interest income				$ 259	196
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Four, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Acquisition Date 7/22/2014
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Interest income				$ 1,163	878
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, One, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Acquisition Date 12/30/2019
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]
Interest income				$ 11	8
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Seven, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Acquisition Date 9/30/2019
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Interest income				$ 3	2
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Six, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Acquisition Date 5/24/2017
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Interest income				$ 71	53
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Three, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Acquisition Date 7/22/2014
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]	American Community Homes, Inc. [ Member]
Interest income				$ 755	575
Investment, Identifier [Axis]: American Community Homes, Inc., Senior Secured Loans, Two, Due 12/31/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				American Community Homes, Inc. [ Member]		American Community Homes, Inc. [ Member]
Investment, Identifier [Axis]: Aras Corporation ( Revolver), Senior Secured Loans, due 4/13/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ArasCorporationMember		mrcc:ArasCorporationMember
Investment, Identifier [Axis]: Aras Corporation, Senior Secured Loans, due 4/13/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ArasCorporationMember		mrcc:ArasCorporationMember
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, One, due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ArcstorMidcoLLCMember
Investment, Identifier [Axis]: Arcstor Midco, L L C, Senior Secured Loans, Two, due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ArcstorMidcoLLCMember
Investment, Identifier [Axis]: Arcstor Midco, LLC, Due 3/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ArcstorMidcoLLCMember
Investment, Identifier [Axis]: Ascent Midco, L L C ( Revolver), Senior Secured Loans Due 2/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]		Ascent Midco, L L C [ Member]
Interest income				$ 2	3
Investment, Identifier [Axis]: Ascent Midco, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Ascent Midco, L L C [ Member]	Ascent Midco, L L C [ Member]		Ascent Midco, L L C [ Member]
Dividend income				$ 152	141
Investment, Identifier [Axis]: Ascent Midco, L L C, Senior Secured Loans Due 2/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Ascent Midco, L L C [ Member]		Ascent Midco, L L C [ Member]
Interest income				$ 384	359
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Five, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Four, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, One, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Three, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Identifier [Axis]: Attom Intermediate Holdco, L L C, Senior Secured Loans, Two, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Identifier [Axis]: Attom Intermediate Holdco, LLC (Revolver), Senior Secured Loans, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AttomIntermediateHoldcoLLCMember		mrcc:AttomIntermediateHoldcoLLCMember
Investment, Identifier [Axis]: Avalara, Inc. (Revolver), Senior Secured Loans, due 10/19/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AvalaraInc.Member		mrcc:AvalaraInc.Member
Investment, Identifier [Axis]: Avalara, Inc. Senior Secured Loans, due 10/19/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:AvalaraInc.Member		mrcc:AvalaraInc.Member
Investment, Identifier [Axis]: Avison Young ( U S A) Inc., Senior Secured Loans, due 1/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BLSTOperatingCompanyLLCMember		mrcc:BLSTOperatingCompanyLLCMember
Investment, Identifier [Axis]: B L S T Operating Company, L L C, Senior Secured Loans, due 8/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BLSTOperatingCompanyLLCMember		mrcc:BLSTOperatingCompanyLLCMember
Investment, Identifier [Axis]: Bluesight, Inc (Revolver) Senior Secured Loans 7/17/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BluesightIncMember
Investment, Identifier [Axis]: Bluesight, Inc Senior Secured Loans, 7/17/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BluesightIncMember
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Class B Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BluesightIncMember
Investment, Identifier [Axis]: Bluesight, Inc., Equity Securities, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BluesightIncMember
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Delayed Draw) , Senior Secured Loans, due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings) ( Revolver), Senior Secured Loans, due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Bonterra, L L C (fka Cybergrants Holdings), Senior Secured Loans, due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Bonterra, LLC (Revolver), Senior Secured Loans, Due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, One, Due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Bonterra, LLC, Senior Secured Loans, Two, Due 9/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BonterraLLCfkaCybergrantsHoldingsMember
Investment, Identifier [Axis]: Born To Run, L L C ( Delayed Draw) Senior Secured Loans, due 4/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:BornToRunLLCMember
Investment, Identifier [Axis]: Born To Run, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BornToRunLLCMember		mrcc:BornToRunLLCMember
Investment, Identifier [Axis]: Born To Run, L L C, Senior Secured Loans, due 4/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BornToRunLLCMember		mrcc:BornToRunLLCMember
Investment, Identifier [Axis]: Born To Run, LLC, Senior Secured Loans, Two, Due 4/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BornToRunLLCMember
Investment, Identifier [Axis]: Brickell Bay Acquisition Corp, Senior Secured Loans, due 2/12/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BrickellBayAcquisitionCorpMember		mrcc:BrickellBayAcquisitionCorpMember
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, One, due 11/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Bromford Industries Limited, Senior Secured Loans, Two, due 11/5/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Burroughs, Inc. ( Revolver), Senior Secured Loans, due 12/22/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:BurroughsInc.Member
Investment, Identifier [Axis]: Burroughs, Inc. (Revolver), Senior Secured Loans, due 12/22/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BurroughsInc.Member
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, One, due 12/22/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:BurroughsInc.Member
Investment, Identifier [Axis]: Burroughs, Inc., Senior Secured Loans, due 12/22/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:BurroughsInc.Member
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, One, due 4/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C H A Holdings, Inc, Senior Secured Loans, Two, due 4/10/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC) (Revolver), Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Equity Securities, Common Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]	C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, One
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Junior Secured Loans, Two
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Investment, Identifier [Axis]: C Parent Holdings, LLC. (fka Curion Holdings, LLC), Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]		C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Interest income				$ 172	1,766
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, One, due 12/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CgiAutomatedManufacturingLlcMember		mrcc:CgiAutomatedManufacturingLlcMember
Investment, Identifier [Axis]: CGI Automated Manufacturing, LLC, Senior Secured Loans, Two, due 12/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCPShawAcquisitioncoLLCMember		mrcc:CgiAutomatedManufacturingLlcMember
Investment, Identifier [Axis]: Cadent, L L C ( Revolver), Senior Secured Loans, due 9/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Cadent, L L C, Senior Secured Loans, due 9/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Calabrio, Inc. ( Revolver), Senior Secured Loans, due 4/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CalabrioIncMember		mrcc:CalabrioIncMember
Investment, Identifier [Axis]: Calabrio, Inc., Senior Secured Loans, due 4/16/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CalabrioIncMember		mrcc:CalabrioIncMember
Investment, Identifier [Axis]: California Pizza Kitchen, Inc., Equity Securities, Common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:CaliforniaPizzaKitchenInc.Member
Investment, Identifier [Axis]: Cano Health, L L C, Senior Secured Loans, due 11/23/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Caravel Autism Health LLC One Senior Secured Loans due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CaravelAutismHealthLLCMember
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Delayed Draw), Senior Secured Loans, due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:CaravelAutismHealthLLCMember
Investment, Identifier [Axis]: Caravel Autism Health, L L C ( Revolver), Senior Secured Loans, due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CaravelAutismHealthLLCMember		mrcc:CaravelAutismHealthLLCMember
Investment, Identifier [Axis]: Caravel Autism Health, L L C, Senior Secured Loans, due 6/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CaravelAutismHealthLLCMember		mrcc:CaravelAutismHealthLLCMember
Investment, Identifier [Axis]: Cassavant Holdings, L L C, Unitranche Secured Loans, due 9/8/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CassavantHoldingsLLCMember		mrcc:CassavantHoldingsLLCMember
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Delayed Draw), Senior Secured Loans, due 4/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C ( Revolver), Senior Secured Loans, due 4/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Identifier [Axis]: Centaur ( Palm Beach) Owner L L C and Panther National Golf Club L L C, Senior Secured Loans, due 4/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember		mrcc:CentaurPalmBeachOwnerLLCandPantherNationalGolfClubLLCMember
Investment, Identifier [Axis]: Chess.com, L L C ( Revolver), Senior Secured Loans, due 12/31/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:Chess.comLLCMember		mrcc:Chess.comLLCMember
Investment, Identifier [Axis]: Chess.com, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:Chess.comLLCMember		mrcc:Chess.comLLCMember
Investment, Identifier [Axis]: Chess.com, L L C, Senior Secured Loans, due 12/31/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:Chess.comLLCMember		mrcc:Chess.comLLCMember
Investment, Identifier [Axis]: Corel Inc., Senior Secured Loans, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Crownpeak Technology Inc. (Revolver) Senior Secured Loans, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Four, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans One, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Three, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Investment, Identifier [Axis]: Crownpeak Technology Inc. Senior Secured Loans Two, Due 2/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:CrownpeakTechnologyIncMember		mrcc:CrownpeakTechnologyIncMember
Investment, Identifier [Axis]: Curion Holdings, L L C, Equity Securities, Common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						Curion Holdings, L L C [ Member]
Investment, Identifier [Axis]: Curion Holdings, LLC (Revolver), Senior Secured Loans, Two, Acquisition Date 5/2/2017
Transactions with Affiliated Companies
Interest income					294
Investment, Identifier [Axis]: D S Parent, Inc., Senior Secured Loans, due 12/8/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Destination Media, Inc. ( Revolver), Senior Secured Loans, due 4/7/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:DestinationMediaIncMember
Investment, Identifier [Axis]: Destination Media, Inc. (Delayed Draw), Senior Secured Loans, due 6/21/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DestinationMediaIncMember
Investment, Identifier [Axis]: Destination Media, Inc. (Revolver), Senior Secured Loans, due 6/21/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DestinationMediaIncMember
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 4/7/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:DestinationMediaIncMember
Investment, Identifier [Axis]: Destination Media, Inc., Senior Secured Loans, due 6/21/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DestinationMediaIncMember
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, One, Class A-1 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DoradoAcquisitionIncMember		mrcc:DoradoAcquisitionIncMember
Investment, Identifier [Axis]: Dorado Acquisition, Inc, Equity Securities, Two, Class A-2 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DoradoAcquisitionIncMember		mrcc:DoradoAcquisitionIncMember
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Delayed Draw) , Senior Secured Loans, due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:DoradoAcquisitionInc.Member
Investment, Identifier [Axis]: Dorado Acquisition, Inc. ( Revolver) , Senior Secured Loans, due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DoradoAcquisitionInc.Member		mrcc:DoradoAcquisitionInc.Member
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, One, due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DoradoAcquisitionInc.Member		mrcc:DoradoAcquisitionInc.Member
Investment, Identifier [Axis]: Dorado Acquisition, Inc., Senior Secured Loans, Two, Due 6/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DoradoAcquisitionInc.Member		mrcc:DoradoAcquisitionInc.Member
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Delayed Draw), Senior Secured Loans, due 9/1/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Investment, Identifier [Axis]: Drawbridge Partners, LLC (Revolver), Senior Secured Loans, due 9/1/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Investment, Identifier [Axis]: Drawbridge Partners, LLC, Senior Secured Loans, due 9/1/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:DrawbridgePartnersLlcMember		mrcc:DrawbridgePartnersLlcMember
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, One, due 10/1/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Dresser Utility Solutions, L L C (fka N G S U S Finco, L L C), Senior Secured Loans, Two, due 10/1/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Drilling Info Holdings, Inc., Senior Secured Loans, due 7/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Education Corporation of America, Equity Securities, Series G Preferred Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:EducationCorporationofAmericaMember		mrcc:EducationCorporationofAmericaMember
Investment, Identifier [Axis]: Education Corporation of America, Junior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:EducationCorporationofAmericaMember		mrcc:EducationCorporationofAmericaMember
Investment, Identifier [Axis]: Elevate Textiles, Inc. (fka International Textile Group, Inc.), Senior Secured Loans, due 9/30/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C ( Delayed Draw), Senior Secured Loans, due 4/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Eliassen Group, L L C, Senior Secured Loans, due 4/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc. ( Revolver), Senior Secured Loans, due 3/7/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, One, due 3/7/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Engage2 Excel, Inc., Senior Secured Loans, Two,due 3/7/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Equine Network, L L C, (Delayed Draw), Senior Secured Loans, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:EquineNetworkLLCMember
Investment, Identifier [Axis]: Equine Network, L L C, (Revolver), Senior Secured Loans, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:EquineNetworkLLCMember
Investment, Identifier [Axis]: Equine Network, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:EquineNetworkLLCMember		mrcc:EquineNetworkLLCMember
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, One, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:EquineNetworkLLCMember
Investment, Identifier [Axis]: Equine Network, L L C, Senior Secured Loans, Two, due 12/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:EquineNetworkLLCMember
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc. ( Revolver), Senior Secured Loans, due 4/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Excel Fitness Holdings, Inc., Senior Secured Loans, due 4/27/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Express Wash Acquisition Company, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC (Revolver), Senior Secured Loans, due 7/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, One, Due 7/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Identifier [Axis]: Express Wash Acquisition Company, LLC, Senior Secured Loans, Two, Due 7/14/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ExpressWashAcquisitionCompanyLLCMember		mrcc:ExpressWashAcquisitionCompanyLLCMember
Investment, Identifier [Axis]: Familia Dental Group Holdings, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Familia Dental Group Holdings, LLC		Familia Dental Group Holdings, LLC
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Junior Secured Loans, due 6/28/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:FloridaEastCoastIndustriesLLCMember		mrcc:FloridaEastCoastIndustriesLLCMember
Investment, Identifier [Axis]: Florida East Coast Industries, L L C, Senior Secured Loans, due 6/28/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:FloridaEastCoastIndustriesLLCMember
Investment, Identifier [Axis]: Forman Mills, Inc, Equity Securities, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:FormanMillsInc.Member
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, One, due 4/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:FormanMillsIncMember
Investment, Identifier [Axis]: Forman Mills, Inc, Senior Secured Loans, Two, due 4/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:FormanMillsIncMember
Investment, Identifier [Axis]: Forman Mills, Inc., Senior Secured Loans, due 6/20/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:FormanMillsInc.Member
Investment, Identifier [Axis]: GC Champion Acquisition LLC (Delayed Draw), Senior Notes, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:GCChampionAcquisitionLLCMember
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:GCChampionAcquisitionLLCMember
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, One, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:GCChampionAcquisitionLLCMember
Investment, Identifier [Axis]: GC Champion Acquisition LLC, Senior Notes, Two, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:GCChampionAcquisitionLLCMember
Investment, Identifier [Axis]: GC Champion Acquisition Llc Senior Notes Three Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:GCChampionAcquisitionLLCMember
Investment, Identifier [Axis]: H A H Group Holding Company L L C, Senior Secured Loans, due 10/29/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H A L O Buyer, Inc., Senior Secured Loans, due 6/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans , Two
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HFZCapitalGroupLLCMember	mrcc:HFZCapitalGroupLLCMember		mrcc:HFZCapitalGroupLLCMember
Interest income				$ 629	514
Investment, Identifier [Axis]: H F Z Capital Group L L C, Senior Secured Loans, One
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:HFZCapitalGroupLLCMember		mrcc:HFZCapitalGroupLLCMember
Interest income				$ 1,749	1,430
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc. ( Revolver), Senior Secured Loans, due 7/9/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:HS4AcquisitioncoIncMember		mrcc:HS4AcquisitioncoIncMember
Investment, Identifier [Axis]: H S4 Acquisitionco, Inc., Senior Secured Loans, due 7/9/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:HS4AcquisitioncoIncMember		mrcc:HS4AcquisitioncoIncMember
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, One, due 12/13/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Harbour Benefit Holdings, Inc., Senior Secured Loans, Two, due 12/13/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Hastings Manufacturing Company (Revolver), Senior Secured Loans, Due 12/31/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:HastingsManufacturingCompanyMember
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, One, Due 12/31/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:HastingsManufacturingCompanyMember
Investment, Identifier [Axis]: Hastings Manufacturing Company , Senior Secured Loans, Two, Due 12/31/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:HastingsManufacturingCompanyMember
Investment, Identifier [Axis]: Hastings Manufacturing Company, Senior Secured Loans, due 4/24/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:HastingsManufacturingCompanyMember
Investment, Identifier [Axis]: I D I G Parent, L L C, Equity Securities, Common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				I D I G Parent, L L C [ Member]		I D I G Parent, L L C [ Member]
Investment, Identifier [Axis]: I N H Buyer, Inc., Senior Secured Loans, due 6/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:INHBuyerInc.Member		mrcc:INHBuyerInc.Member
Investment, Identifier [Axis]: In Mobi Pte, Ltd, Media: Equity Securities, due 9/18/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:InMobiPteLtdMember		mrcc:InMobiPteLtdMember
Investment, Identifier [Axis]: Independence Buyer, Inc, Senior Secured Loans, due 8/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:IndependenceBuyerInc.Member		mrcc:IndependenceBuyerInc.Member
Investment, Identifier [Axis]: Independence Buyer, Inc. ( Revolver), Senior Secured Loans, due 8/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:IndependenceBuyerInc.Member		mrcc:IndependenceBuyerInc.Member
Investment, Identifier [Axis]: Independence Buyer, Inc., Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:IndependenceBuyerInc.Member		mrcc:IndependenceBuyerInc.Member
Investment, Identifier [Axis]: Intermedia Holdings, Inc., Senior Secured Loans, due 7/21/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: J2 B W A Funding L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:J2BWAFundingLLCMember		mrcc:J2BWAFundingLLCMember
Investment, Identifier [Axis]: J2 BWA Funding LLC (Delayed Draw), Senior Notes, Due 12/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:J2BWAFundingLLCMember
Investment, Identifier [Axis]: J2 Bwa Funding Llc Revolver Senior Notes Due 12/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:J2BWAFundingLLCMember
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Revolver) Senior Secured Loans Due
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KlMoonAcquisitionLlcMember
Investment, Identifier [Axis]: KL Moon Acquisition Llc (fka Spectrum Science Communications, LLC) Senior Secured Loans Due 2/1/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KlMoonAcquisitionLlcMember
Investment, Identifier [Axis]: KL Moon Acquisition, LLC (fka Spectrum Science Communications, LLC), Equity Securities, Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KlMoonAcquisitionLlcMember
Investment, Identifier [Axis]: Kar Wash Holdings LLC Equity Securities Series A Preferred Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KarWashHoldingsLLCMember
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Investment, Identifier [Axis]: Kar Wash Holdings, L L C ( Revolver), Senior Secured Loans, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Investment, Identifier [Axis]: Kar Wash Holdings, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, One, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Investment, Identifier [Axis]: Kar Wash Holdings, LLC, Senior Secured Loans, Two, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KarWashHoldingsLLCMember		mrcc:KarWashHoldingsLLCMember
Investment, Identifier [Axis]: Keystone Purchaser, L L C, Senior Secured Loans, due 5/7/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, One, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Delayed Draw), Senior Secured Loans, Two, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KingsleyGatePartnersLlcMember		mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC (Revolver), Senior Secured Loans, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KingsleyGatePartnersLlcMember		mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, , Senior Secured Loans, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, One Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kingsley Gate Partners, LLC, Two, Due 12/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KingsleyGatePartnersLlcMember
Investment, Identifier [Axis]: Kl Moon Acquisition Llc (fka Spectrum Science Communications, LLC) (Delayed Draw) Senior Secured Loans Due
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:KlMoonAcquisitionLlcMember
Investment, Identifier [Axis]: L S C S Holdings, Inc., Senior Secured Loans, due 12/15/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: L V F Holdings, Inc. ( Revolver), Senior Secured Loans, due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LXJTIntermediateHoldingsIncMember		mrcc:LVFHoldingsIncMember
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, ( Delayed Draw) due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:LVFHoldingsIncMember
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, One, due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LVFHoldingsIncMember		mrcc:LVFHoldingsIncMember
Investment, Identifier [Axis]: L V F Holdings, Inc., Senior Secured Loans, Two, due 6/10/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LVFHoldingsIncMember		mrcc:LVFHoldingsIncMember
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc. ( Revolver), Senior Secured Loans, due 3/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LXJTIntermediateHoldingsIncMember		mrcc:LXJTIntermediateHoldingsIncMember
Investment, Identifier [Axis]: L X/ J T Intermediate Holdings, Inc., Senior Secured Loans, due 3/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LXJTIntermediateHoldingsIncMember		mrcc:LXJTIntermediateHoldingsIncMember
Investment, Identifier [Axis]: Laseraway Intermediate Holdings I I, L L C, Senior Secured Loans, due 10/14/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Delayed Draw), Senior Secured Loans, due 8/2/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:LiftedTrucksHoldingsLLCMember
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C ( Revolver), Senior Secured Loans, due 8/2/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LiftedTrucksHoldingsLLCMember		mrcc:LiftedTrucksHoldingsLLCMember
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LiftedTrucksHoldingsLLCMember		mrcc:LiftedTrucksHoldingsLLCMember
Investment, Identifier [Axis]: Lifted Trucks Holdings, L L C, Senior Secured Loans, due 8/2/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LiftedTrucksHoldingsLLCMember		mrcc:LiftedTrucksHoldingsLLCMember
Investment, Identifier [Axis]: Liftforward SPV II LLC Senior Secured Loans Due 9/29/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:LiftforwardSPVIILLCMember
Investment, Identifier [Axis]: Liftforward SPV II, LLC, Senior Secured Loans, due 3/31/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:LiftforwardSPVIILLCMember
Investment, Identifier [Axis]: Lightbox Intermediate, L. P., Senior Secured Loans, due 5/11/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Luxury Optical Holdings Co., Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:LuxuryOpticalHoldingsCo.Member
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C ( Delayed Draw), Senior Secured Loans Due 1/26/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember		mrcc:MCAssetManagementCorporateLLCMember
Interest income				$ 417	111
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securites
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCAssetManagementCorporateLLCMember		mrcc:MCAssetManagementCorporateLLCMember
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCAssetManagementCorporateLLCMember	mrcc:MCAssetManagementCorporateLLCMember
Investment, Identifier [Axis]: M C Asset Management ( Corporate), L L C, Senior Secured Loans Due 1/26/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:HFZCapitalGroupLLCMember	mrcc:MCAssetManagementCorporateLLCMember		mrcc:MCAssetManagementCorporateLLCMember
Interest income				$ 1,417	940
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C ( Revolver), Senior Secured Loans, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C , Equity Securities, Class A-2 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, One, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Investment, Identifier [Axis]: M C P Shaw Acquisitionco, L L C, Senior Secured Loans, Two, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Investment, Identifier [Axis]: M R C C Senior Loan Fund I, L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Controlled affiliate company investments			Controlled affiliate company investments		Controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				MRCC Senior Loan Fund I, LLC		MRCC Senior Loan Fund I, LLC
Dividend income				$ 2,700	2,700
Investment, Identifier [Axis]: M V Receivables I I, L L C ( Delayed Draw), Senior Secured Loans, due 7/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MVReceivablesIILLCMember
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MVReceivablesIILLCMember		mrcc:MVReceivablesIILLCMember
Investment, Identifier [Axis]: M V Receivables I I, L L C, Equity Securities, Due 7/28/2031, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MVReceivablesIILLCMember		mrcc:MVReceivablesIILLCMember
Investment, Identifier [Axis]: M V Receivables I I, L L C, Senior Secured Loans, due 7/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MVReceivablesIILLCMember
Investment, Identifier [Axis]: MC Asset Management (Corporate), LLC, Senior Secured Loans, Two, Due 1/26/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCAssetManagementCorporateLLCMember
Investment, Identifier [Axis]: MCP Shaw Acquisitionco, LLC, Senior Secured Loans, Three, due 11/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MCPShawAcquisitioncoLLCMember		mrcc:MCPShawAcquisitioncoLLCMember
Investment, Identifier [Axis]: MEI Buyer LLC (Delayed Draw), Senior Secured Loans, due 6/29/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MeiBuyerLlcMember
Investment, Identifier [Axis]: MEI Buyer LLC (Revolver), Senior Secured Loans, due 6/29/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MeiBuyerLlcMember
Investment, Identifier [Axis]: MEI Buyer LLC, Equity Securities, Common Stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MeiBuyerLlcMember
Investment, Identifier [Axis]: MEI Buyer LLC, Senior Secured Loans, due 6/29/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MeiBuyerLlcMember
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Delayed Draw), Senior Secured Loans, due 1/7/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C ( Revolver), Senior Secured Loans, due 1/7/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mac Queen Equipment, L L C, Senior Secured Loans, due 1/7/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mammoth Holdings, LLC (Revolver), Senior Secured Loans, Due, 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MammothHoldingsLLCMember		mrcc:MammothHoldingsLLCMember
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MammothHoldingsLLCMember
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Four, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MammothHoldingsLLCMember
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, One, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MammothHoldingsLLCMember
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Three, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MammothHoldingsLLCMember
Investment, Identifier [Axis]: Mammoth Holdings, LLC, Senior Secured Loans, Two, due 10/16/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MammothHoldingsLLCMember
Investment, Identifier [Axis]: Mark Logic Corporation ( Revolver), Senior Secured Loans, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MarkLogicCorporationMember
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Four, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MarkLogicCorporationMember
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, One, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MarkLogicCorporationMember
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Three, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MarkLogicCorporationMember
Investment, Identifier [Axis]: Mark Logic Corporation, Senior Secured Loans, Two, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MarkLogicCorporationMember
Investment, Identifier [Axis]: MarkLogic Corporation, Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MarkLogicCorporationMember
Investment, Identifier [Axis]: Mavenir Systems, Inc., Senior Secured Loans, due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mc Kissock Investment Holdings, L L C, Senior Secured Loans, due 3/9/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Medallia, Inc, Senior Secured Loans, due 10/27/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MedalliaIncMember		mrcc:MedalliaIncMember
Investment, Identifier [Axis]: Mindbody, Inc. ( Revolver) (f), Senior Secured Loans, due 2/14/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MindbodyIncMember		mrcc:MedalliaIncMember
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, One, due 2/14/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MindbodyIncMember		mrcc:MedalliaIncMember
Investment, Identifier [Axis]: Mindbody, Inc., Senior Secured Loans, Two, due 2/14/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MindbodyIncMember		mrcc:MedalliaIncMember
Investment, Identifier [Axis]: Minotaur Acquisition, Inc., Senior Secured Loans, due 3/27/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, One 12/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Mnine Holdings, Inc [ Member]
Investment, Identifier [Axis]: Mnine Holdings Inc, Senior Secured Loans Due, Two 12/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Mnine Holdings, Inc [ Member]
Investment, Identifier [Axis]: Mnine Holdings, Inc (Revolver), Senior Secured Loans, Due 12/30/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Mnine Holdings, Inc [ Member]
Investment, Identifier [Axis]: Mnine Holdings, Inc, Senior Secured Loans, Due 12/30/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						Mnine Holdings, Inc [ Member]
Investment, Identifier [Axis]: Mnine Holdings, Inc. (Revolver), Senior Secured Loans, due 12/30/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Mnine Holdings, Inc [ Member]		Mnine Holdings, Inc [ Member]
Interest income				$ 47
Investment, Identifier [Axis]: Mnine Holdings, Inc., Equity Securities, Class B units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]	Mnine Holdings, Inc [ Member]		Mnine Holdings, Inc [ Member]
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due 12/30/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Mnine Holdings, Inc [ Member]
Interest income				$ 600	567
Investment, Identifier [Axis]: Mnine Holdings, Inc., Senior Secured Loans Due Two 12/30/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Mnine Holdings, Inc [ Member]
Interest income					2
Investment, Identifier [Axis]: Money Lion, Inc. ( Delayed Draw), Junior Secured Loans, due 3/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MoneyLionIncMember
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 10/16/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MoneyLionIncMember
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 3/24/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:MoneyLionIncMember		mrcc:MoneyLionIncMember
Investment, Identifier [Axis]: Money Lion, Inc., Junior Secured Loans, due 5/1/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MoneyLionIncMember
Investment, Identifier [Axis]: N C B P Property, L L C, Senior Secured Loans, due 12/16/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:NCBPPropertyLLCMember
Investment, Identifier [Axis]: N E C B Collections, L L C ( Revolver), Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				N E C B Collections, L L C [ Member]		N E C B Collections, L L C [ Member]
Investment, Identifier [Axis]: N E C B Collections, L L C, Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			N E C B Collections, L L C [ Member]	N E C B Collections, L L C [ Member]		N E C B Collections, L L C [ Member]
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Delayed Draw), Senior Secured Loans, Due 10/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc. (Revolver), Senior Secured Loans, Due 10/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Equity Securities, Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Identifier [Axis]: NQ PE Project Colosseum Midco Inc., Senior Secured Loans, Due 10/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NqPeProjectColosseumMidcoInc.Member		mrcc:NqPeProjectColosseumMidcoInc.Member
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, One, Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Investment, Identifier [Axis]: Nations Benefits L L C, Senior Secured Loans, Two, Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Investment, Identifier [Axis]: Nations Benefits LLC Delayed Draw, Senior Secured Loans Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Investment, Identifier [Axis]: Nations Benefits, L L C (Revolver), Senior Secured Loans, Due 8/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, One, Series B units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Investment, Identifier [Axis]: Nations Benefits, L L C, Equity Securities, Two, common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NationsBenefitsLLCMember		mrcc:NationsBenefitsLLCMember
Investment, Identifier [Axis]: Natus Medical Incorporated, Senior Secured Loans, due 7/20/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Nearly Natural Inc. Senior Secured Loans One due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NearlyNaturalInc.Member
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Four, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NearlyNaturalInc.Member
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Three, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NearlyNaturalInc.Member
Investment, Identifier [Axis]: Nearly Natural Inc., Senior Secured Loans, Two, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NearlyNaturalInc.Member
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, One, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NearlyNaturalIncMember		mrcc:NearlyNaturalInc.Member
Investment, Identifier [Axis]: Nearly Natural, Inc, Equity Securities, Two, Class A A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NearlyNaturalIncMember		mrcc:NearlyNaturalInc.Member
Investment, Identifier [Axis]: Nearly Natural, Inc. (Revolver), Senior Secured Loans, due 3/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NearlyNaturalInc.Member
Investment, Identifier [Axis]: Nearly Natural, Inc.( Revolver), Senior Secured loans, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:NearlyNaturalIncMember
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Four, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:NearlyNaturalIncMember
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, One, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:NearlyNaturalIncMember
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Three, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:NearlyNaturalIncMember
Investment, Identifier [Axis]: Nearly Natural, Inc., Senior Secured loans, Two, due 12/15/2022
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:NearlyNaturalIncMember
Investment, Identifier [Axis]: Newforma, Inc. ( Revolver) (f), Senior Secured Loans, due 3/31/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MedalliaIncMember
Investment, Identifier [Axis]: Newforma, Inc., Senior Secured Loans, due 3/31/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:MedalliaIncMember
Investment, Identifier [Axis]: North Haven Spartan U S Holdco, L L C, Senior Secured Loans, due 6/6/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Delayed Draw), Senior Secured Loans, due, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc. ( Revolver), Senior Secured Loans, due, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, One, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Identifier [Axis]: North Haven U S H C Acquisition, Inc., Senior Secured Loans, due, Two, 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Four, due 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Identifier [Axis]: North Haven USHC Acquisition, Inc, Senior Secured Loans, Three, due 10/30/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:NorthHavenUSHCAcquisitionIncMember		mrcc:NorthHavenUSHCAcquisitionIncMember
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, One, due 6/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:OceanaAustralianFixedIncomeTrustMember
Investment, Identifier [Axis]: Oceana Australian Fixed Income Trust, Senior Secured Loans, Two, due 2/25/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:OceanaAustralianFixedIncomeTrustMember
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, One, due 6/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Offen, Inc., Senior Secured Loans, Two, due 6/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Onit, Inc., Unitranche Secured Loans, due 5/2/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:OnitInc.Member		mrcc:OnitInc.Member
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, One, due 10/21/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Three, due 10/21/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Orbit Purchaser L L C, Senior Secured Loans, Two, due 10/21/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Output Services Group Inc. Senior Secured Loans Due 6/29/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P H Beauty Holdings I I I, I N C., Senior Secured Loans, due 9/26/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Four, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, One, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Three, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Investment, Identifier [Axis]: P K S Holdings, L L C, Equity Securities, Two, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PKSHoldingsLLCMember		mrcc:PKSHoldingsLLCMember
Investment, Identifier [Axis]: P V H C Holding Corp, Senior Secured Loans, due 2/17/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Panda Acquisition, LLC, Senior Secured Loans, due 10/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PandaAcquisitionLlcMember		mrcc:PandaAcquisitionLlcMember
Investment, Identifier [Axis]: Paragon Healthcare Inc. Senior Secured Loan Due 1/19/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Delayed Draw Senior Secured Loans due 1/19/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Paragon HealthcareInc. Revolver Senior Secured Loan Due 1/19/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Phoenix Chemical Holding Company LLC (fka Polymer Solutions Group), Senior Secured Loan due 8/2/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Five, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PlanfulInc.Member
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Four, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, One, due 12/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Three, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Investment, Identifier [Axis]: Planful, Inc, Senior Secured Loans, Two, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Investment, Identifier [Axis]: Planful, Inc. ( Revolver), Senior Secured Loans, due 12/28/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PlanfulInc.Member		mrcc:PlanfulIncMember
Investment, Identifier [Axis]: Planful, Inc., Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PlanfulInc.Member		mrcc:PlanfulInc.Member
Investment, Identifier [Axis]: Polychem Acquisition, L L C, Senior Secured Loans, due 3/17/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Prototek LLC (Delayed Draw), Senior Secured Loans, Due 12/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PrototekLlcMember		mrcc:PrototekLlcMember
Investment, Identifier [Axis]: Prototek LLC (Revolver), Senior Secured Loans, Due 12/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PrototekLlcMember		mrcc:PrototekLlcMember
Investment, Identifier [Axis]: Prototek LLC, Senior Secured Loans, Due 12/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:PrototekLlcMember		mrcc:PrototekLlcMember
Investment, Identifier [Axis]: Quest Resource Management Group, L L C ( Delayed Draw), Senior Secured Loans, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:QuestResourceManagementGroupLLCMember
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securites, Two, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Equity Securities, One, Warrants
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, One, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Three, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Investment, Identifier [Axis]: Quest Resource Management Group, L L C, Senior Secured Loans, Two, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:QuestResourceManagementGroupLLCMember		mrcc:QuestResourceManagementGroupLLCMember
Investment, Identifier [Axis]: Quest Resource Management Group, LLC, Senior Secured Loans, Four, Due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:QuestResourceManagementGroupLLCMember
Investment, Identifier [Axis]: Radiology Partners, Inc., Senior Secured Loans, due 7/9/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Recorded Future, Inc, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Recorded Future, Inc [ Member]		Recorded Future, Inc [ Member]
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C ( Revolver), Senior Secured Loans, due 8/4/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RecycledPlasticsIndustriesLLCMember		mrcc:RecycledPlasticsIndustriesLLCMember
Investment, Identifier [Axis]: Recycled Plastics Industries, L L C, Senior Secured Loans, due 8/4/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RecycledPlasticsIndustriesLLCMember		mrcc:RecycledPlasticsIndustriesLLCMember
Investment, Identifier [Axis]: Relativity O D A L L C ( Revolver), Senior Secured Loans, due 5/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RelativityODALLCMember		mrcc:RelativityODALLCMember
Investment, Identifier [Axis]: Relativity O D A L L C, Senior Secured Loans, due 5/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RelativityODALLCMember		mrcc:RelativityODALLCMember
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Delayed Draw), Senior Secured Loans, due, 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:RelevateHealthGroupLLCMember
Investment, Identifier [Axis]: Relevate Health Group, L L C ( Revolver), Senior Secured Loans, due, 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, Class B common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Investment, Identifier [Axis]: Relevate Health Group, L L C, Equity Securities, preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Investment, Identifier [Axis]: Relevate Health Group, L L C, Senior Secured Loans, due, 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RelevateHealthGroupLLCMember		mrcc:RelevateHealthGroupLLCMember
Investment, Identifier [Axis]: Relevate Health Group, LLC, Senior Secured Loans, Two, Due 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RelevateHealthGroupLLCMember
Investment, Identifier [Axis]: Research Now Group, Inc. and Survey Sampling International, L L C, Senior Secured Loans, due 12/20/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Rockdale Blackhawk, L L C, Senior Secured Loans, no stated maturity
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:RockdaleBlackhawkLLCMember
Investment, Identifier [Axis]: Rockdale Blackhawk, LLC, Senior Secured Loans, due, 11/30/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:RockdaleBlackhawkLLCMember
Investment, Identifier [Axis]: Runner Buyer I N C., Senior Secured Loans, due 10/23/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S F R Holdco, L L C Equity Securities
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			S F R Holdco, L L C [ Member]	S F R Holdco, L L C [ Member]
Investment, Identifier [Axis]: S F R Holdco, L L C, Junior Secured Loans Due 7/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				S F R Holdco, L L C [ Member]
Interest income				$ 351	351
Investment, Identifier [Axis]: S I R V A Worldwide Inc., Senior Secured Loans, due 8/4/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S T A T S Intermediate Holdings, L L C, Senior Secured Loans, due 7/10/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: S W Ingredients Holdings, L L C, Senior Secured Loans, due 7/3/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: SFR Holdco, LLC, Equity Securities, 24.4% of Interest
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				S F R Holdco, L L C [ Member]		mrcc:SfrHoldcoLlcEquitySecurities24.4OfInterestMember
Investment, Identifier [Axis]: Sandvine Corporation, Senior Secured Loans, due 10/31/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C ( Revolver), Senior Secured Loans, Due 8/9/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				Second Avenue S F R Holdings I I L L C [ Member]		Second Avenue S F R Holdings I I L L C [ Member]
Interest income				$ 434	182
Investment, Identifier [Axis]: Second Avenue S F R Holdings I I L L C, Junior Secured Loans, Due 7/28/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						Second Avenue S F R Holdings I I L L C [ Member]
Investment, Identifier [Axis]: Secretariat Advisors L L C, Senior Secured Loans, due 12/29/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Secretariat Advisors LLC, Senior Secured Loans, Two, due 12/29/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Five, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Four, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, One, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Three, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Identifier [Axis]: Security Services Acquisition Sub Corp., Senior Secured Loans, Two, due 9/30/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SecurityServicesAcquisitionSubCorpMember		mrcc:SecurityServicesAcquisitionSubCorpMember
Investment, Identifier [Axis]: Seran Bio Science, L L C ( Revolver), Senior Secured Loans, due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Investment, Identifier [Axis]: Seran Bio Science, L L C, Equity Securities, common units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Investment, Identifier [Axis]: Seran Bio Science, L L C, Senior Secured Loans, due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Investment, Identifier [Axis]: Seran BioScience, LLC (Delayed Draw), Senior Secured Loans, Due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SeranBioScienceLLCMember		mrcc:SeranBioScienceLLCMember
Investment, Identifier [Axis]: Seran Bioscience Llc (Delayed Draw) One Senior Secured Loans Due 7/8/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SeranBioScienceLLCMember
Investment, Identifier [Axis]: Service Max, Inc. ( Revolver) , Senior Secured Loans, due 11/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ServiceMaxIncMember
Investment, Identifier [Axis]: Service Max, Inc., Senior Secured Loans, due 11/1/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ServiceMaxIncMember
Investment, Identifier [Axis]: Sparq Holdings Inc. Delayed Draw Senior Secured Loans Due 6/15/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SparqHoldingsInc.Member
Investment, Identifier [Axis]: Sparq Holdings Inc. Revolver Senior Secured Loans Due 6/15/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SparqHoldingsInc.Member
Investment, Identifier [Axis]: Sparq Holdings Inc. Senior Secured Loans Due 6/15/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SparqHoldingsInc.Member
Investment, Identifier [Axis]: Sparq Holdings, Inc. Senior Secured Loans
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SparqHoldingsInc.Member
Investment, Identifier [Axis]: Spectrum Science Communications, L L C ( Revolver), Senior Secured Loans, due 1/25/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:SpectrumScienceCommunicationsLLCMember
Investment, Identifier [Axis]: Spectrum Science Communications, L L C, Senior Secured Loans, due 1/25/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:SpectrumScienceCommunicationsLLCMember
Investment, Identifier [Axis]: Spherix Global Inc, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SpherixGlobalIncMember		mrcc:SpherixGlobalInc.Member
Investment, Identifier [Axis]: Spherix Global Inc. ( Revolver), Senior Secured Loans, due, 12/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SpherixGlobalInc.Member		mrcc:SpherixGlobalIncMember
Investment, Identifier [Axis]: Spherix Global Inc. , Senior Secured Loans, due, 12/22/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SpherixGlobalInc.Member		mrcc:SpherixGlobalIncMember
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Delayed Draw), Due 11/3/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SportsOperatingHoldingsIiLlcMember		mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC (Revolver), Due, 11/3/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SportsOperatingHoldingsIiLlcMember		mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Identifier [Axis]: Sports Operating Holdings II, LLC, Due, 11/3/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:SportsOperatingHoldingsIiLlcMember		mrcc:SportsOperatingHoldingsIiLlcMember
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, ( Revolver), Senior Secured Loans, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:StarComplianceMidCoLLCMember		mrcc:StarComplianceMidCoLLCMember
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, One, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:StarComplianceMidCoLLCMember		mrcc:StarComplianceMidCoLLCMember
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Three, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:StarComplianceMidCoLLCMember
Investment, Identifier [Axis]: Star Compliance Mid Co, L L C, Senior Secured Loans, Two, due 1/12/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:StarComplianceMidCoLLCMember		mrcc:StarComplianceMidCoLLCMember
Investment, Identifier [Axis]: T A T T Buyer, L L C, Senior Secured Loans, due 3/30/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, One, due 4/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TCFIIIOWLBuyerLLCMember		mrcc:TCFIIIOWLBuyerLLCMember
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Three, due 4/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TCFIIIOWLBuyerLLCMember		mrcc:TCFIIIOWLBuyerLLCMember
Investment, Identifier [Axis]: T C F I I I O W L Buyer L L C, Senior Secured Loans, Two, due 4/17/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TCFIIIOWLBuyerLLCMember		mrcc:TCFIIIOWLBuyerLLCMember
Investment, Identifier [Axis]: T E A M Public Choices, L L C, Senior Secured Loans, due 12/17/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T G G T S Acquisition Company, Senior Secured Loans, due 12/12/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J C Spartech Acquisition Corp., Senior Secured Loans, due 5/5/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: T J Management Hold Co L L C ( Revolver), Senior Secured Loans, Due 6/28/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments			Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				T J Management Hold Co L L C [ Member]		T J Management Hold Co L L C [ Member]
Interest income				$ 13	9
Investment, Identifier [Axis]: T J Management Hold Co L L C, Equity Securities, Common stock
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled affiliate company investments		Non-controlled affiliate company investments	Non-controlled affiliate company investments		Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			T J Management Hold Co L L C [ Member]	T J Management Hold Co L L C [ Member]		T J Management Hold Co L L C [ Member]
Investment, Identifier [Axis]: Tait L L C ( Revolver), Senior Secured Loans, due 3/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Tait L L C, Senior Secured Loans, due 3/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Teneo Holdings L L C, Senior Secured Loans, due 7/11/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Cook & Boardman Group L L C, Senior Secured Loans, due 10/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kleinfelder Group, Inc., Senior Secured Loans, due 11/29/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: The Kyjen Company, L L C ( Revolver), Senior Secured Loans, due 4/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TheKyjenCompanyLLCMember		mrcc:TheKyjenCompanyLLCMember
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior SEcured Loans, Two, Due 4/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TheKyjenCompanyLLCMember		mrcc:TheKyjenCompanyLLCMember
Investment, Identifier [Axis]: The Kyjen Company, L L C, Senior Secured Loans, due 4/3/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TheKyjenCompanyLLCMember		mrcc:TheKyjenCompanyLLCMember
Investment, Identifier [Axis]: Thrasio, L L C, Senior Secured Loans, due 12/18/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ThrasioLLCMember		mrcc:ThrasioLLCMember
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Delayed Draw), Senior Secured Loans, due 2/16/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TigerConnectIncMember		mrcc:TigerConnectIncMember
Investment, Identifier [Axis]: Tiger Connect, Inc. ( Revolver), Senior Secured Loans, due 2/16/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TigerConnectIncMember		mrcc:TigerConnectIncMember
Investment, Identifier [Axis]: Tiger Connect, Inc., Senior Secured Loans, due 2/16/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:TigerConnectIncMember		mrcc:TigerConnectIncMember
Investment, Identifier [Axis]: Trident Maritime Systems, Inc ( Revolver), Senior Secured Loans, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, One, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Trident Maritime Systems, Inc, Senior Secured Loans, Two, due 2/26/2027
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, One, due 12/14/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck- Lite Co., L L C, Senior Secured Loans, Two, due 12/14/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Truck-Lite Co., LLC, Senior Secured Loans, Three, due 12/14/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: V B E1, L L C ( Delayed Draw), Unitranche Secured Loans, due 11/18/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:VBE1LLCMember
Investment, Identifier [Axis]: V B E1, L L C, Unitranche Secured Loans, due 11/18/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:VBE1LLCMember
Investment, Identifier [Axis]: V P S Holdings, L L C ( Revolver), Senior Secured Loans, due 10/4/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:VPSHoldingsLLCMember		mrcc:VPSHoldingsLLCMember
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, One, due 10/4/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:VPSHoldingsLLCMember		mrcc:VPSHoldingsLLCMember
Investment, Identifier [Axis]: V P S Holdings, L L C, Senior Secured Loans, Two, due 10/4/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:VPSHoldingsLLCMember		mrcc:VPSHoldingsLLCMember
Investment, Identifier [Axis]: V10 Entertainment, Inc, Equity Securities, Common Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				V10 Entertainment, Inc. [Member]
Investment, Identifier [Axis]: V10 Entertainment, Inc. (Revolver), Senior Secured Loans, Due 1/12/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				V10 Entertainment, Inc. [Member]
Investment, Identifier [Axis]: V10 Entertainment, Inc., Senior Secured Loans, Due 1/12/2028
Transactions with Affiliated Companies
Investment, Issuer Name [Extensible Enumeration]				V10 Entertainment, Inc. [Member]
Investment, Identifier [Axis]: Valudor Products L L C ( Revolver), Senior Secured Loans, due 6/19/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products L L C , Equity Securities, Class A-1 units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ValudorProductsLLCMember		mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, One, due 6/19/2023,
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Three, due 6/19/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products L L C, Senior Secured Loans, Two, due 6/19/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products LLC (Revolver), Senior Secured Loans, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, One, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Three, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Valudor Products LLC, Senior Secured Loans, Two, due 9/15/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ValudorProductsLLCMember
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Delayed Draw), Senior Secured Loans, due 6/8/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:VhagarPurchaserLlcMember
Investment, Identifier [Axis]: Vhagar Purchaser, LLC (Revolver), Senior Secured Loans, due, 6/8/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:VhagarPurchaserLlcMember
Investment, Identifier [Axis]: Vhagar Purchaser, LLC, Senior Secured Loans, due 6/8/2029
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:VhagarPurchaserLlcMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Equity Securities, Class A Units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Five, due 1/31/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Four, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, One, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Three, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Junior Secured Loans, Two, No Maturity Date
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceAcquisitionHoldcoLlcFkaViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, One, due 1/31/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Three, due 1/31/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Acquisition Holdco, LLC (fka Vice Group Holding Inc.), Senior Secured Loans, Two, due 12/12/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:ViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Four, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, One, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Three, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vice Group Holding Inc., Senior Secured Loans, Two, due 5/12/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:ViceGroupHoldingIncMember
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Four, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, One, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Three, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: Vinci Brands L L C, Unitranche Secured Loans, Two, due 2/6/2024
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:VinciBrandsLLCMember
Investment, Identifier [Axis]: W3 Monroe R E Debt L L C, Senior Secured Loans, due 2/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:W3MonroeREDebtLLCMember		mrcc:W3MonroeREDebtLLCMember
Investment, Identifier [Axis]: W3 Monroe RE Debt LLC (Delayed Draw), Senior Secured Loans, Due 2/4/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:W3MonroeREDebtLLCMember
Investment, Identifier [Axis]: Wheel Pros, Inc., Senior Secured Loans, due 5/11/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Delayed Draw), Senior Secured Loans, due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc. ( Revolver), Senior Secured Loans, due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:WhistlerParentHoldingsIIIIncMember		mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Identifier [Axis]: Whistler Parent Holdings I I I, Inc., Senior Secured Loans, due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:WhistlerParentHoldingsIIIIncMember		mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Identifier [Axis]: Whistler Parent Holdings III Inc. One Senior Secured Loans due 6/2/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:WhistlerParentHoldingsIIIIncMember
Investment, Identifier [Axis]: WillowTree, LLC, Unitranche Secured Loans, due 10/9/2023
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:WillowTreeLLCMember
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C ( Delayed Draw), Junior Secured Loans, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:WitkoffMonroe700JVLLCMember		mrcc:WitkoffMonroe700JVLLCMember
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Equity Securities, Preferred units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:WitkoffMonroe700JVLLCMember		mrcc:WitkoffMonroe700JVLLCMember
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, One, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:WitkoffMonroe700JVLLCMember
Investment, Identifier [Axis]: Witkoff/ Monroe 700 J V L L C, Junior Secured Loans, Two, due 7/2/2026
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:WitkoffMonroe700JVLLCMember
Investment, Identifier [Axis]: Xan Edu Publishing, Inc, Equity Securities, Class A units
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:XanEduPublishingIncMember		mrcc:XanEduPublishingIncMember
Investment, Identifier [Axis]: Xan Edu Publishing, Inc. ( Revolver), Senior Secured Loans, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:XanEduPublishingIncMember		mrcc:XanEduPublishingIncMember
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, One, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:XanEduPublishingIncMember		mrcc:XanEduPublishingIncMember
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, Two, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:XanEduPublishingIncMember
Investment, Identifier [Axis]: Xan Edu Publishing, Inc., Senior Secured Loans, due, 1/28/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:XanEduPublishingIncMember
Investment, Identifier [Axis]: Y S W H 4, L L C (Revolver), Senior Secured Loans, Due 11/20/2025
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]						Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]						mrcc:YSWH4LLCRevolverMember
Investment, Identifier [Axis]: iCIMS, Inc., Senior Secured Loans, Due 8/18/2028
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]	Non-controlled/non-affiliate company investments			Non-controlled/non-affiliate company investments		Non-controlled/non-affiliate company investments
Investment, Issuer Name [Extensible Enumeration]				mrcc:IcimsIncMember		mrcc:IcimsIncMember
Non-controlled affiliate company investments
Transactions with Affiliated Companies
Interest income				$ 8,959	8,621
Dividend income	$ 52	$ 48		152	141
Non-controlled affiliate company investments | American Community Homes, Inc. [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			American Community Homes, Inc. [ Member]
Interest income				2,744	2,093
Non-controlled affiliate company investments | Ascent Midco, L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Ascent Midco, L L C [ Member]
Interest income				386	362
Dividend income				152	141
Non-controlled affiliate company investments | C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			C Parent Holdings, LLC. (fka Curion Holdings, LLC) [Member]
Interest income				172	2,060
Non-controlled affiliate company investments | Familia Dental Group Holdings, LLC
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Familia Dental Group Holdings, LLC
Non-controlled affiliate company investments | H F Z Capital Group, L L C And M C Asset Management ( Corporate), L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			mrcc:MCAssetManagementCorporateLLCMember
Interest income				4,212	2,995
Non-controlled affiliate company investments | Mnine Holdings, Inc [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Mnine Holdings, Inc [ Member]
Interest income				647	569
Non-controlled affiliate company investments | N E C B Collections, L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			N E C B Collections, L L C [ Member]
Non-controlled affiliate company investments | Second Avenue S F R Holdings I I L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			Second Avenue S F R Holdings I I L L C [ Member]
Interest income				434	182
Non-controlled affiliate company investments | S F R Holdco, L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			S F R Holdco, L L C [ Member]
Interest income				351	351
Non-controlled affiliate company investments | T J Management Hold Co L L C [ Member]
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Non-controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			T J Management Hold Co L L C [ Member]
Interest income				13	9
Controlled affiliate company investments
Transactions with Affiliated Companies
Dividend income	$ 900	$ 900		2,700	2,700
Controlled affiliate company investments | MRCC Senior Loan Fund I, LLC
Transactions with Affiliated Companies
Investment, Issuer Affiliation [Extensible Enumeration]			Controlled affiliate company investments
Investment, Issuer Name [Extensible Enumeration]			MRCC Senior Loan Fund I, LLC
Dividend income				$ 2,700	$ 2,700

Transactions with Related Par_3

Transactions with Related Parties (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) item component	Sep. 30, 2022 USD ($)
Transactions with Related Parties
Base management fees	$ 2,140	$ 2,222	$ 6,503	$ 6,834
MC Advisors
Transactions with Related Parties
Number of components | component			2
Initial base management fee, Percentage			1.75%
Base management fee, percentage			1%
Percentage of average invested assets			200%
Leverage ratio	1		1
Base management fees	$ 2,140	2,222	$ 6,503	6,834
Base management fees, voluntary waiver amount		$ 0		$ 55
Incentive fee payable in arrears, percentage			20%
Incentive fee payable, threshold quarterly hurdle rate			2%
Incentive fee payable, threshold annual hurdle rate			8%
Incentive fee limitation, percentage			20%
Period of preceding calendar quarters | item			11
Threshold ordinary income incentive fee payable, percentage			20%
Threshold ordinary income incentive fee limitation, percentage			20%
Second part incentive fee payable, percentage			20%

Transactions with Related Par_4

Transactions with Related Parties - Composition of the Company's incentive fees (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Transactions with Related Parties
Total incentive fees, net of incentive fee waivers	$ 1,355	$ 1,565	$ 4,493	$ 2,747
MC Advisors
Transactions with Related Parties
Part one incentive fees	1,355	1,565	4,493	2,747
Incentive fees, excluding the impact of the incentive fee waivers	1,355	1,565	4,493	2,747
Incentive fee waivers				(525)
Total incentive fees, net of incentive fee waivers	$ 1,355	$ 1,565	$ 4,493	$ 2,222
Second part incentive fee payable, percentage			20%

Transactions with Related Par_5

Transactions with Related Parties - Administrative agreement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Transactions with Related Parties
Administrative agreement service fee	$ 228	$ 275	$ 707	$ 908
MC Management
Transactions with Related Parties
Administrative expenses		703
MC Management | Accounts payable and accrued expenses
Transactions with Related Parties
Amount due to related party	245		245		$ 255
Related party	245		245		255
Members of Board
Transactions with Related Parties
Amount due to related party	38		38		0
Related party	38		38		$ 0
MC Management
Transactions with Related Parties
Administrative expenses	721		2,041	2,370
Administrative agreement service fee	$ 228	$ 275	$ 707	$ 908

Borrowings (Details)

Borrowings (Details) £ in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
	Mar. 01, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 GBP (£)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Aug. 15, 2022	Feb. 15, 2022
Borrowings
Minimum asset coverage ratio		150%		150%
Asset coverage ratio		163%		163%			167%
Unrealized gain (loss) on foreign currency and other transactions		$ 1				$ 164
Realized gain (loss) on foreign currency and other transactions		$ (4)	$ (1)	$ (135)		(38)
Interest rate, daily rate per annum		1.50%		1.50%
Total debt		$ 331,100		$ 331,100			$ 334,600
Realized loss on extinguishment of debt	$ 1,039					(1,039)
Notes 2026
Borrowings
Interest rate								4.75%	4.75%
Total debt		130,000		130,000			130,000
Revolving credit facility
Borrowings
Maximum borrowing capacity		255,000		$ 255,000
Maximum borrowing capacity, Percentage of the fair market value of its portfolio company investments				72.50%	72.50%
Consolidated total net assets		$ 150,000		$ 150,000
Consolidated total net assets, Percentage of net proceeds from sales of equity securities after March 1, 2019		65%		65%
Percentage of distributions in cash or property other than common stock		115%		115%
Borrowings		$ 201,100		$ 201,100			$ 204,600
Unrealized gain (loss) on foreign currency and other transactions		$ 0	$ 0	$ 0		157
Repayments of borrowings | £					£ 3,433
Realized gain (loss) on foreign currency and other transactions						$ (11)
Interest rate		2.625%		2.625%
Interest rate, daily rate per annum		1.625%		1.625%
Weighted average interest rate		8.10%		8.10%			7%
Revolving credit facility | Minimum
Borrowings
Assets to debt ratio		1		1
Senior debt coverage ratio		1		1
Revolving credit facility | Maximum
Borrowings
Maximum borrowing capacity		$ 400,000		$ 400,000
Assets to debt ratio		1.5		1.5
Senior debt coverage ratio		2		2
Revolving credit facility | Available maximum borrowing capacity percentage greater than 35%
Borrowings
Commitment fee (in percent)				0.50%	0.50%
Available maximum borrowing capacity, percentage		35%		35%
Revolving credit facility | Available maximum borrowing capacity percentage equal to or less than 35%
Borrowings
Commitment fee (in percent)				1%	1%
Available maximum borrowing capacity, percentage		35%		35%
Revolving credit facility | Federal funds rate
Borrowings
Interest rate		0.50%		0.50%
Revolving credit facility | SOFR
Borrowings
Interest rate, basis spread				1%	1%
Interest rate, floor		0.50%		0.50%
Revolving credit facility | Denominated in U.S. dollar
Borrowings
Borrowings							$ 204,600

Borrowings - SBA Debentures (De

Borrowings - SBA Debentures (Details) - USD ($) $ in Thousands		9 Months Ended
	Mar. 01, 2022	Sep. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Borrowings
Realized loss on extinguishment of debt	$ 1,039	$ (1,039)
Outstanding borrowings			$ 327,534	$ 330,114

Borrowings - Components of the

Borrowings - Components of the Company's interest expense and other debt financing expenses, average debt outstanding balances and average stated interest rates (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Borrowings
Amortization of deferred financing costs	$ 330	$ 522	$ 977	$ 1,613
Total interest and other debt financing expenses	5,874	4,263	17,178	11,961
Average debt outstanding	$ 319,759	$ 292,879	$ 322,918	$ 315,166
Average stated interest rate	6.80%	5%	6.70%	4.30%
Notes 2026
Borrowings
Interest expense	$ 1,555	$ 1,555	$ 4,665	$ 4,665
SBA Debentures
Borrowings
Interest expense				292
Revolving credit facility
Borrowings
Interest expense	$ 3,989	$ 2,186	$ 11,536	$ 5,391

Derivative Instruments (Details

Derivative Instruments (Details) $ in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 AUD ($)
Derivative Instruments
Gross Amount of Unrealized Gain					$ 1,507
Net change in unrealized gain (loss) on foreign currency forward contracts		$ 863	$ (1,507)	$ 1,503
Foreign currency forward contracts
Derivative Instruments
Net change in unrealized gain (loss) on foreign currency forward contracts	$ 0	863	(1,507)	1,503
Net realized gain (loss) on foreign currency forward contracts	$ 0	$ 38	$ 1,756	$ 69
Foreign currency forward contract with Settlement Date 1/18/2023
Derivative Instruments
Notional Amount to be Sold						$ 153
Gross Amount of Unrealized Gain					14
Foreign currency forward contract with Settlement Date 2/16/2023
Derivative Instruments
Notional Amount to be Sold						140
Gross Amount of Unrealized Gain					13
Foreign currency forward contract with Settlement Date 3/16/2023
Derivative Instruments
Notional Amount to be Sold						132
Gross Amount of Unrealized Gain					12
Foreign currency forward contract with Settlement Date 4/20/2023
Derivative Instruments
Notional Amount to be Sold						160
Gross Amount of Unrealized Gain					14
Foreign currency forward contract with Settlement Date 5/16/2023
Derivative Instruments
Notional Amount to be Sold						121
Gross Amount of Unrealized Gain					11
Foreign currency forward contract with Settlement Date 6/19/2023
Derivative Instruments
Notional Amount to be Sold						156
Gross Amount of Unrealized Gain					14
Foreign currency forward contract with Settlement Date 7/18/2023
Derivative Instruments
Notional Amount to be Sold						138
Gross Amount of Unrealized Gain					12
Foreign currency forward contract with Settlement Date 8/16/2023
Derivative Instruments
Notional Amount to be Sold						146
Gross Amount of Unrealized Gain					13
Foreign currency forward contract with Settlement Date 9/18/2023
Derivative Instruments
Notional Amount to be Sold						146
Gross Amount of Unrealized Gain					13
Foreign currency forward contract with Settlement Date 10/18/2023
Derivative Instruments
Notional Amount to be Sold						148
Gross Amount of Unrealized Gain					13
Foreign currency forward contract with Settlement Date 11/16/2023
Derivative Instruments
Notional Amount to be Sold						140
Gross Amount of Unrealized Gain					12
Foreign currency forward contract with Settlement Date 12/18/2023
Derivative Instruments
Notional Amount to be Sold						142
Gross Amount of Unrealized Gain					12
Foreign currency forward contract with Settlement Date 1/17/2024
Derivative Instruments
Notional Amount to be Sold						150
Gross Amount of Unrealized Gain					13
Foreign currency forward contract with Settlement Date 2/16/2024
Derivative Instruments
Notional Amount to be Sold						143
Gross Amount of Unrealized Gain					12
Foreign currency forward contract with Settlement Date 3/18/2024
Derivative Instruments
Notional Amount to be Sold						$ 15,410
Gross Amount of Unrealized Gain					$ 1,329

Distributions (Details)

Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended				9 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Distributions
Date Declared	Mar. 01, 2023	Mar. 02, 2022	Sep. 01, 2023	Jun. 02, 2023	Sep. 01, 2022	Jun. 01, 2022
Record Date	Mar. 15, 2023	Mar. 16, 2022	Sep. 15, 2023	Jun. 15, 2023	Sep. 15, 2022	Jun. 15, 2022
Payment Date	Mar. 31, 2023	Mar. 31, 2022	Sep. 29, 2023	Jun. 30, 2023	Sep. 30, 2022	Jun. 30, 2022
Amount Per Share	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.75	$ 0.75
Cash Distribution	$ 5,417	$ 5,417	$ 5,417	$ 5,417	$ 5,416	$ 5,416	$ 16,251	$ 16,249
DRIP Shares Repurchased in Open Market	10,380	25,229	16,514	9,045	20,789	29,655	35,939	75,673
Cost of DRIP Shares Repurchased	$ 81	$ 276	$ 123	$ 73	$ 164	$ 280	$ 277	$ 720

Stock Issuances and Repurchas_2

Stock Issuances and Repurchases (Details) - ATM offering - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	May 12, 2017
Stock Issuances and Repurchases
Maximum value of common stock available for sale			$ 50,000
Number of stock issued	0	0

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Commitments
Unfunded commitments	$ 41,899	$ 63,450
SLF
Commitments
Unfunded commitments	$ 7,350	$ 7,350

Financial Highlights - Financia

Financial Highlights - Financial highlights (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Per share data:
Net asset value at beginning of period	$ 10.39	$ 11.51
Net investment income	0.83	0.77
Net gain (loss)	(0.89)	(1.10)
Net increase (decrease) in net assets resulting from operations	(0.06)	(0.33)
Stockholder distributions - income	(0.75)	(0.75)
Net asset value at end of period	$ 9.58	$ 10.43
Net assets at end of period	$ 207,555	$ 225,956
Shares outstanding at end of period	21,666,340	21,666,340
Per share market value at end of period	$ 7.45	$ 7.24
Total return based on market value	(4.08%)	(30.10%)
Total return based on average net asset value	(0.56%)	(3.05%)
Ratio/Supplemental data:
Ratio of net investment income to average net assets	11.76%	9.67%
Ratio of total expenses, net of base management fee and incentive fee waivers, to average net assets	18.28%	13.58%
Portfolio turnover	9.91%	17.53%

Financial Highlights - (Details

Financial Highlights - (Details)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Financial Highlights
Ratio of total investment income to average net assets	30.04%	23.25%
Ratio of interest and other debt financing expenses to average net assets	10.57%	6.72%
Ratio of total expenses (without base management fee waivers and incentive fees) to average net assets	16.21%	12.67%
Ratio of incentive fees, net of incentive fee waivers, to average net assets	2.07%	0.93%
Ratio of waived incentive fees to average net assets	0%	0.22%

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ (236)	$ (749)	$ (1,213)	$ (7,266)

Insider Trading Arrangements

Insider Trading Arrangements	9 Months Ended
	Sep. 30, 2023
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Rule 10b5-1
Rule 10b5-1 Arrangement Adopted	true