Blackstone Mortgage Trust (BXMT) 10-Q 27 Oct 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 20, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001061630
Current Fiscal Year End Date	--12-31
Document Period End Date	Sep. 30, 2021
Trading Symbol	BXMT
Entity Registrant Name	Blackstone Mortgage Trust, Inc.
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		157,080,951
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity File Number	001-14788
Entity Tax Identification Number	94-6181186
Entity Incorporation, State or Country Code	MD
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Address, Address Line One	345 Park Avenue, 24th Floor
Entity Address, City or Town	New York
Entity Address, Postal Zip Code	10154
City Area Code	212
Local Phone Number	655-0220
Title of 12(b) Security	Class A common stock
Security Exchange Name	NYSE
Entity Address, State or Province	NY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Cash and cash equivalents	$ 211,180	$ 289,970
Loans receivable	20,406,466	16,572,715
Current expected credit loss reserve	(130,388)	(173,549)
Loans receivable, net	20,276,078	16,399,166
Other assets	218,614	269,819
Total Assets	20,705,872	16,958,955
Liabilities and Equity
Secured debt, net	11,170,330	7,880,536
Securitized debt obligations, net	2,836,049	2,922,499
Asset-specific debt, net	320,895	391,269
Term loans, net	1,329,637	1,041,704
Convertible notes, net	618,985	616,389
Other liabilities	159,424	202,327
Total Liabilities	16,435,320	13,054,724
Commitments and contingencies
Equity
Class A common stock, $0.01 par value, 400,000,000 shares authorized, 157,015,689 and 146,780,031 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	1,570	1,468
Additional paid-in capital	5,039,384	4,702,713
Accumulated other comprehensive income	9,874	11,170
Accumulated deficit	(814,278)	(829,284)
Total Blackstone Mortgage Trust, Inc. stockholders' equity	4,236,550	3,886,067
Non-controlling interests	34,002	18,164
Total Equity	4,270,552	3,904,231
Total Liabilities and Equity	$ 20,705,872	$ 16,958,955

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Common stock, par value in dollars per share	$ 0.01	$ 0.01
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	157,015,689	146,780,031
Common stock, shares outstanding	157,015,689	146,780,031
Assets	$ 20,705,872	$ 16,958,955
Liabilities	16,435,320	13,054,724
Variable Interest Entity, Primary Beneficiary [Member]
Assets	3,503,362	3,587,950
Liabilities	$ 2,837,680	$ 2,924,603

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income from loans and other investments
Interest and related income	$ 200,114	$ 193,939	$ 583,941	$ 590,797
Less: Interest and related expenses	82,690	78,978	243,413	268,070
Income from loans and other investments, net	117,424	114,961	340,528	322,727
Other expenses
Management and incentive fees	19,342	18,985	60,094	58,758
General and administrative expenses	10,841	11,242	32,108	34,320
Total other expenses	30,183	30,227	92,202	93,078
(Increase) decrease in current expected credit loss reserve	(2,767)	6,055	49,432	(173,466)
Income before income taxes	84,474	90,789	297,758	56,183
Income tax provision	70	20	346	192
Net income	84,404	90,769	297,412	55,991
Net income attributable to non-controlling interests	(647)	(909)	(2,158)	(1,937)
Net income attributable to Blackstone Mortgage Trust, Inc.	$ 83,757	$ 89,860	$ 295,254	$ 54,054
Net income per share of common stock basic and diluted	$ 0.56	$ 0.61	$ 2	$ 0.39
Weighted-average shares of common stock outstanding, basic and diluted	149,214,819	146,484,651	147,971,737	140,157,620

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net income	$ 84,404	$ 90,769	$ 297,412	$ 55,991
Other comprehensive income
Unrealized (loss) gain on foreign currency translation	(46,952)	62,656	(66,356)	14,488
Realized and unrealized gain (loss) on derivative financial instruments	46,083	(61,936)	65,059	11,390
Other comprehensive (loss) income	(869)	720	(1,297)	25,878
Comprehensive income	83,535	91,489	296,115	81,869
Comprehensive income attributable to non-controlling interests	(647)	(909)	(2,158)	(1,937)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 82,888	$ 90,580	$ 293,957	$ 79,932

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Adoption of ASU 2016-13, see Note 2 [Member]	Class A Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]Adoption of ASU 2016-13, see Note 2 [Member]	Stockholders' Equity [Member]	Stockholders' Equity [Member]Adoption of ASU 2016-13, see Note 2 [Member]	Non-controlling Interests [Member]	Non-controlling Interests [Member]Adoption of ASU 2016-13, see Note 2 [Member]
Balance at Dec. 31, 2019	$ 3,784,681		$ 1,350	$ 4,370,014	$ (16,233)	$ (592,548)		$ 3,762,583		$ 22,098
Balance (Accounting Standards Update 2016-13 [Member]) at Dec. 31, 2019		$ (17,650)					$ (17,565)		$ (17,565)		$ (85)
Shares of class A common stock issued, net	4		4					4
Restricted class A common stock earned	8,550			8,550				8,550
Dividends reinvested	174			162		12		174
Deferred directors' compensation	125			125				125
Other comprehensive income (loss)	34,481				34,481			34,481
Net (loss) income	(53,283)					(53,350)		(53,350)		67
Dividends declared on common stock and deferred stock units, $0.62 per share	(84,082)					(84,082)		(84,082)
Contributions from non-controlling interests	8,108									8,108
Distributions to non-controlling interests	(6,681)									(6,681)
Balance at Mar. 31, 2020	3,674,427		1,354	4,378,851	18,248	(747,533)		3,650,920		23,507
Balance at Dec. 31, 2019	3,784,681		1,350	4,370,014	(16,233)	(592,548)		3,762,583		22,098
Balance (Accounting Standards Update 2016-13 [Member]) at Dec. 31, 2019		$ (17,650)					$ (17,565)		$ (17,565)		$ (85)
Other comprehensive income (loss)	25,878
Net (loss) income	55,991
Balance at Sep. 30, 2020	3,903,952		1,462	4,693,982	9,645	(821,725)		3,883,364		20,588
Balance at Mar. 31, 2020	3,674,427		1,354	4,378,851	18,248	(747,533)		3,650,920		23,507
Shares of class A common stock issued, net	297,599		108	297,491				297,599
Restricted class A common stock earned	8,527			8,527				8,527
Dividends reinvested	178			165		13		178
Deferred directors' compensation	125			125				125
Other comprehensive income (loss)	(9,323)				(9,323)			(9,323)
Net (loss) income	18,505					17,544		17,544		961
Dividends declared on common stock and deferred stock units, $0.62 per share	(90,807)					(90,807)		(90,807)
Distributions to non-controlling interests	(3,447)									(3,447)
Balance at Jun. 30, 2020	3,895,784		1,462	4,685,159	8,925	(820,783)		3,874,763		21,021
Restricted class A common stock earned	8,524			8,524				8,524
Dividends reinvested	188			174		14		188
Deferred directors' compensation	125			125				125
Other comprehensive income (loss)	720				720			720
Net (loss) income	90,769					89,860		89,860		909
Dividends declared on common stock and deferred stock units, $0.62 per share	(90,816)					(90,816)		(90,816)
Contributions from non-controlling interests	323									323
Distributions to non-controlling interests	(1,665)									(1,665)
Balance at Sep. 30, 2020	3,903,952		1,462	4,693,982	9,645	(821,725)		3,883,364		20,588
Balance at Dec. 31, 2020	3,904,231		1,468	4,702,713	11,170	(829,284)		3,886,067		18,164
Shares of class A common stock issued, net	2		2					2
Restricted class A common stock earned	7,958			7,958				7,958
Dividends reinvested	204			204				204
Deferred directors' compensation	125			125				125
Other comprehensive income (loss)	114				114			114
Net (loss) income	80,540					79,902		79,902		638
Dividends declared on common stock and deferred stock units, $0.62 per share	(91,349)					(91,349)		(91,349)
Contributions from non-controlling interests	13,448									13,448
Distributions to non-controlling interests	(11,180)									(11,180)
Balance at Mar. 31, 2021	3,904,093		1,470	4,711,000	11,284	(840,731)		3,883,023		21,070
Balance at Dec. 31, 2020	3,904,231		1,468	4,702,713	11,170	(829,284)		3,886,067		18,164
Other comprehensive income (loss)	(1,297)
Net (loss) income	297,412
Balance at Sep. 30, 2021	4,270,552		1,570	5,039,384	9,874	(814,278)		4,236,550		34,002
Balance at Mar. 31, 2021	3,904,093		1,470	4,711,000	11,284	(840,731)		3,883,023		21,070
Restricted class A common stock earned	7,895			7,895				7,895
Dividends reinvested	211			211				211
Deferred directors' compensation	125			125				125
Other comprehensive income (loss)	(541)				(541)			(541)
Net (loss) income	132,468					131,595		131,595		873
Dividends declared on common stock and deferred stock units, $0.62 per share	(91,347)					(91,347)		(91,347)
Contributions from non-controlling interests	14,745									14,745
Distributions to non-controlling interests	(10,694)									(10,694)
Balance at Jun. 30, 2021	3,956,955		1,470	4,719,231	10,743	(800,483)		3,930,961		25,994
Shares of class A common stock issued, net	311,955		100	311,855				311,955
Restricted class A common stock earned	7,907			7,907				7,907
Dividends reinvested	218			218				218
Deferred directors' compensation	173			173				173
Other comprehensive income (loss)	(869)				(869)			(869)
Net (loss) income	84,404					83,757		83,757		647
Dividends declared on common stock and deferred stock units, $0.62 per share	(97,552)					(97,552)		(97,552)
Contributions from non-controlling interests	19,068									19,068
Distributions to non-controlling interests	(11,707)									(11,707)
Balance at Sep. 30, 2021	$ 4,270,552		$ 1,570	$ 5,039,384	$ 9,874	$ (814,278)		$ 4,236,550		$ 34,002

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Dividends declared on common stock, per share	$ 0.62	$ 0.62	$ 0.62	$ 0.62	$ 0.62	$ 0.62	$ 1.86	$ 1.86

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net income	$ 297,412	$ 55,991
Adjustments to reconcile net income to net cash provided by operating activities
Satisfaction of management and incentive fees in stock	0	19,277
Non-cash compensation expense	24,184	25,978
Amortization of deferred fees on loans and debt securities	(43,299)	(43,516)
Amortization of deferred financing costs and premiums/ discounts on debt obligations	29,698	28,122
(Decrease) increase in current expected credit loss reserve	(49,432)	173,466
Unrealized gain on assets denominated in foreign currencies, net	(7,088)	(648)
Unrealized gain on derivative financial instruments, net	(3,298)	(754)
Realized loss (gain) on derivative financial instruments, net	5,483	(481)
Changes in assets and liabilities, net
Other assets	(12,106)	8,713
Other liabilities	13,468	(4,852)
Net cash provided by operating activities	255,022	261,296
Cash flows from investing activities
Origination and fundings of loans receivable	(7,449,491)	(1,489,101)
Principal collections and sales proceeds from loans receivable and debt securities	3,423,460	1,358,640
Origination and exit fees received on loans receivable	79,971	14,215
Receipts under derivative financial instruments	44,428	87,286
Payments under derivative financial instruments	(75,458)	(98,216)
Collateral deposited under derivative agreements	(94,060)	(255,830)
Return of collateral deposited under derivative agreements	145,110	277,280
Net cash used in investing activities	(3,926,040)	(105,726)
Cash flows from financing activities
Borrowings under secured debt	7,701,481	2,317,616
Repayments under secured debt	(4,239,614)	(3,506,154)
Proceeds from issuance of securitized debt obligations	803,750	1,243,125
Repayment of securitized debt obligations	(888,763)	(253,260)
Borrowings under asset-specific debt	106,443	111,225
Repayments under asset-specific debt	(178,073)	(82,754)
Net proceeds from issuance of term loans	298,500	315,438
Repayments of term loans	(10,060)	(6,428)
Payment of deferred financing costs	(29,339)	(34,726)
Contributions from non-controlling interests	47,261	8,431
Distributions to non-controlling interests	(33,581)	(11,793)
Net proceeds from issuance of class A common stock	311,955	278,322
Dividends paid on class A common stock	(273,311)	(258,264)
Net cash provided by financing activities	3,616,649	120,778
Net (decrease) increase in cash, cash equivalents, and restricted cash	(54,369)	276,348
Cash, cash equivalents, and restricted cash at beginning of period	289,970	150,090
Effects of currency translation on cash, cash equivalents, and restricted cash	579	590
Cash, cash equivalents, and restricted cash at end of period	236,180	427,028
Supplemental disclosure of cash flows information
Payments of interest	(207,293)	(242,564)
Receipts (payments) of income taxes	107	(146)
Supplemental disclosure of non-cash investing and financing activities
Dividends declared, not paid	(97,552)	(90,642)
Satisfaction of management and incentive fees in stock	0	19,277
Loan principal payments held by servicer, net	$ 299	$ 3,235

Organization

Organization	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. ORGANIZATION References herein to “Blackstone Mortgage Trust,” “Company,” “we,” “us” or “our” refer to Blackstone Mortgage Trust, Inc. and its subsidiaries unless the context specifically requires otherwise. Blackstone Mortgage Trust is a real estate finance company that originates senior loans collateralized by commercial real estate in North America, Europe, and Australia. Our portfolio is composed primarily of loans secured by high-quality, institutional assets in major markets, sponsored by experienced, well-capitalized real estate investment owners and operators. These senior loans are capitalized by accessing a variety of financing options, including borrowing under our credit facilities, issuing CLOs or single-asset securitizations, and syndicating senior loan participations, depending on our view of the most prudent financing option available for each of our investments. We are not in the business of buying or trading securities, and the only securities we own are the retained interests from our securitization financing transactions, which we have not financed. We are externally managed by BXMT Advisors L.L.C., or our Manager, a subsidiary of Blackstone Inc., or Blackstone, and are a real estate investment trust, or REIT, traded on the New York Stock Exchange, or NYSE, under the symbol “BXMT.” Our principal executive offices are located at 345 Park Avenue, 24th Floor, New York, New York 10154. We were incorporated in Maryland in 1998, when we reorganized from a California common law business trust into a Maryland corporation. We conduct our operations as a REIT for U.S. federal income tax purposes. We generally will not be subject to U.S. federal income taxes on our taxable income to the extent that we annually distribute all of our net taxable income to stockholders and maintain our qualification as a REIT. We also operate our business in a manner that permits us to maintain an exclusion from registration under the Investment Company Act of 1940, as amended. We are organized as a holding company and conduct our business primarily through our various subsidiaries.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, for interim financial information and the instructions to Form 10-Q 10-01 S-X. 10-K Basis of Presentation The accompanying consolidated financial statements include, on a consolidated basis, our accounts, the accounts of our wholly-owned subsidiaries, majority-owned subsidiaries, and variable interest entities, or VIEs, of which we are the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications have been made in the presentation of the prior period statements of changes in equity, statements of cash flows, and loans receivable in Note 3 to conform to the current period presentation. Principles of Consolidation We consolidate all entities that we control through either majority ownership or voting rights. In addition, we consolidate all VIEs of which we are considered the primary beneficiary. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest and/or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary and is generally the entity with (i) the power to direct the activities that most significantly affect the VIE’s economic performance and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. In the third quarter of 2018, we contributed a loan to a single asset securitization vehicle, or the 2018 Single Asset Securitization, which is a VIE, and invested in the related subordinate position. We are not the primary beneficiary of the VIE because we do not have the power to direct the activities that most significantly affect the VIE’s economic performance and, therefore, do not consolidate the 2018 Single Asset Securitization on our balance sheet. We have classified the subordinate position we own as a held-to-maturity In April 2017, we entered into a joint venture, or our Multifamily Joint Venture, with Walker & Dunlop Inc. to originate, hold, and finance multifamily bridge loans. Pursuant to the terms of the agreements governing the joint venture, Walker & Dunlop contributed 15% of the venture’s equity capital and we contributed 85%. We consolidate the Multifamily Joint Venture as we have a controlling financial interest. The non-controlling non-controlling Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The novel coronavirus, or COVID-19 COVID-19 COVID-19. Revenue Recognition Interest income from our loans receivable portfolio and debt securities is recognized over the life of each investment using the effective interest method and is recorded on the accrual basis. Recognition of fees, premiums, and discounts associated with these investments is deferred and recorded over the term of the loan or debt security as an adjustment to yield. Income accrual is generally suspended for loans at the earlier of the date at which payments become 90 days past due or when, in the opinion of our Manager, recovery of income and principal becomes doubtful. Interest received is then recorded as a reduction in the outstanding principal balance until accrual is resumed when the loan becomes contractually current and performance is demonstrated to be resumed. In addition, for loans we originate, the related origination expenses are deferred and recognized as a component of interest income, however expenses related to loans we acquire are included in general and administrative expenses as incurred. Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents represent cash held in banks and liquid investments with original maturities of three months or less. We may have bank balances in excess of federally insured amounts; however, we deposit our cash and cash equivalents with high credit-quality institutions to minimize credit risk exposure. We have not experienced, and do not expect, any losses on our cash or cash equivalents. Restricted cash represents cash collateral held within our 2021 FL4 collateralized loan obligation and is included in Other Assets on our consolidated balance sheets. See Note 6 for further discussion of the 2021 FL4 collateralized loan obligation. The following table provides a reconciliation of cash, cash equivalents, and restricted cash on our consolidated balance sheets to the total amount shown on our consolidated statements of cash flows ($ in thousands): September 30, 2021 September 30, 2020 Cash and cash equivalents $ 211,180 $ 427,028 2021 FL4 CLO restricted cash 25,000 — Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows $ 236,180 $ 427,028 Through our subsidiaries, we have oversight of certain servicing accounts held with third-party servicers, or Servicing Accounts, which relate to borrower escrows and other cash balances aggregating $426.6 million and $384.6 million as of September 30, 2021 and December 31, 2020, respectively. This cash is maintained in segregated bank accounts, and these amounts are not included in the assets and liabilities presented in our consolidated balance sheets. Cash in these Servicing Accounts will be transferred by the respective third-party servicer to the borrower or us under the terms of the applicable loan agreement upon occurrence of certain future events. We do not generate any revenue or incur any expenses as a result of these Servicing Accounts. Loans Receivable We originate and purchase commercial real estate debt and related instruments generally to be held as long-term investments at amortized cost. Debt Securities Held-to-Maturity We classify our debt securities as held-to-maturity, Current Expected Credit Losses Reserve The current expected credit loss, or CECL, reserve required under Accounting Standard Update, or ASU, 2016-13 2016-13, 2016-13 2016-13 We estimate our CECL reserve primarily using the Weighted Average Remaining Maturity, or WARM, method which has been identified as an acceptable loss-rate method for estimating CECL reserves in the Financial Accounting Standards Board Staff Q&A Topic 326, No. 1. The WARM method requires us to reference historic loan loss data across a comparable data set and apply such loss rate to each of our loans over their expected remaining term, taking into consideration expected economic conditions over the relevant timeframe. We apply the WARM method for the majority of our loan portfolio, which loans share similar risk characteristics. In certain instances, for loans with unique risk characteristics, we may instead use a probability-weighted model that considers the likelihood of default and expected loss given default for each such individual loan. Application of the WARM method to estimate a CECL reserve requires judgment, including (i) the appropriate historical loan loss reference data, (ii) the expected timing and amount of future loan fundings and repayments, and (iii) the current credit quality of our portfolio and our expectations of performance, and (iv) market conditions over the relevant time period. To estimate the historic loan losses relevant to our portfolio, we have augmented our historical loan performance, which includes zero realized loan losses since the launch of our senior loan origination business in 2013, with market loan loss data licensed from Trepp LLC. This database includes commercial mortgage-backed securities, or CMBS, issued since January 1, 1999 through August 31, 2021. Within this database, we focused our historical loss reference calculations on the most relevant subset of available CMBS data, which we determined based on loan metrics that are most comparable to our loan portfolio including asset type, geography, and origination loan-to-value, Our loans typically include commitments to fund incremental proceeds to our borrowers over the life of the loan, which future funding commitments are also subject to the CECL model. The CECL reserve related to future loan fundings is recorded as a component of Other Liabilities on our consolidated balance sheets. This CECL reserve is estimated using the same process outlined above for our outstanding loan balances, and changes in this component of the CECL reserve will similarly impact our consolidated net income. For both the funded and unfunded portions of our loans, we consider our internal risk rating of each loan as the primary credit quality indicator underlying our assessment. The CECL reserve is measured on a collective basis wherever similar risk characteristics exist within a pool of similar assets. We have identified the following pools and measure the reserve for credit losses using the following methods: • U.S. Loans • Non-U.S. • Unique Loans • Impaired Loans non-recoverability We adopted ASU 2016-13 Impact of ASU 2016-13 Adoption Assets: Loans U.S. Loans $ 8,955 Non-U.S. 3,631 Unique Loans 1,356 CECL reserve on loans $ 13,942 CECL reserve on held-to-maturity 445 Liabilities: CECL reserve on unfunded loan commitments 3,263 Total impact of ASU 2016-13 $ 17,650 Contractual Term and Unfunded Loan Commitments Expected credit losses are estimated over the contractual term of each loan, adjusted for expected prepayments. As part of our quarterly review of our loan portfolio, we assess the expected repayment date of each loan, which is used to determine the contractual term for purposes of computing our CECL reserve. Additionally, the expected credit losses over the contractual period of our loans are subject to the obligation to extend credit through our unfunded loan commitments. The CECL reserve for unfunded loan commitments is adjusted quarterly, as we consider the expected timing of future funding obligations over the estimated life of the loan. The considerations in estimating our CECL reserve for unfunded loan commitments are similar to those used for the related outstanding loan receivables. Credit Quality Indicator Our risk rating is our primary credit quality indicator in assessing our current expected credit loss reserve. Our Manager performs a quarterly risk review of our portfolio of loans, and assigns each loan a risk rating based on a variety of factors, including, without limitation, LTV, debt yield, property type, geographic and local market dynamics, physical condition, cash flow volatility, leasing and tenant profile, loan structure and exit plan, and project sponsorship. Based on a 5-point 1 - Very Low Risk 2 - Low Risk 3 - Medium Risk 4 - High Risk/Potential for Loss: 5 - Impaired/Loss Likely: Estimation of Economic Conditions In addition to the WARM method computations and probability-weighted models described above, our CECL reserve is also adjusted to reflect our estimation of the current and future economic conditions that impact the performance of the commercial real estate assets securing our loans. These estimations include unemployment rates, interest rates, and other macroeconomic factors impacting the likelihood and magnitude of potential credit losses for our loans during their anticipated term. In addition to the CMBS data we have licensed from Trepp LLC, we have also licensed certain macroeconomic financial forecasts to inform our view of the potential future impact that broader economic conditions may have on our loan portfolio’s performance. These estimations require significant judgments about future events that, while based on the information available to us as of the balance sheet date, are ultimately indeterminate and the actual economic condition impacting our portfolio could vary significantly from the estimates we made as of September 30, 2021. Derivative Financial Instruments We classify all derivative financial instruments as either other assets or other liabilities on our consolidated balance sheets at fair value. On the date we enter into a derivative contract, we designate each contract as (i) a hedge of a net investment in a foreign operation, or net investment hedge, (ii) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability, or cash flow hedge, (iii) a hedge of a recognized asset or liability, or fair value hedge, or (iv) a derivative instrument not to be designated as a hedging derivative, or non-designated non-designated On a quarterly basis, we also formally assess whether the derivative we designated in each hedging relationship is expected to be, and has been, highly effective in offsetting changes in the value or cash flows of the hedged items. If it is determined that a derivative is not highly effective at hedging the designated exposure, hedge accounting is discontinued and the changes in fair value of the instrument are included in net income prospectively. Effective April 1, 2020, our net investment hedges are assessed using a method based on changes in spot exchange rates. Gains and losses, representing hedge components excluded from the assessment of effectiveness, are recognized in interest income on our consolidated statements of operations over the contractual term of our net investment hedges on a systematic and rational basis, as documented at hedge inception in accordance with our accounting policy election. All other changes in the fair value of our derivative instruments that qualify as hedges are reported as a component of accumulated other comprehensive income (loss) on our consolidated financial statements. Deferred gains and losses are reclassified out of accumulated other comprehensive income (loss) and into net income in the same period or periods during which the hedged transaction affects earnings, and are presented in the same line item as the earnings effect of the hedged item. For cash flow hedges, this is typically when the periodic swap settlements are made, while for net investment hedges, this occurs when the hedged item is sold or substantially liquidated. To the extent a derivative does not qualify for hedge accounting and is deemed a non-designated Secured Debt and Asset-Specific Debt We record investments financed with secured debt or asset-specific debt as separate assets and the related borrowings under any secured debt or asset-specific debt are recorded as separate liabilities on our consolidated balance sheets. Interest income earned on the investments and interest expense incurred on the secured debt or asset-specific debt are reported separately on our consolidated statements of operations. Senior Loan Participations In certain instances, we finance our loans through the non-recourse syndication the non-consolidated senior Term Loans We record our term loans as liabilities on our consolidated balance sheets. Where applicable, any issue discount or transaction expenses are deferred and amortized through the maturity date of the term loans as additional non-cash Convertible Notes The “Debt with Conversion and Other Options” Topic of the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, requires the liability and equity components of convertible debt instruments that may be settled in cash upon conversion, including partial cash settlement, to be separately accounted for in a manner that reflects the issuer’s nonconvertible debt borrowing rate. The initial proceeds from the sale of convertible notes are allocated between a liability component and an equity component in a manner that reflects interest expense at the rate of similar nonconvertible debt that could have been issued at such time. The equity component represents the excess initial proceeds received over the fair value of the liability component of the notes as of the date of issuance. We measured the estimated fair value of the debt component of our convertible notes as of the respective issuance dates based on our nonconvertible debt borrowing rate. The equity component of each series of our convertible notes is reflected within additional paid-in non-cash non-cash Deferred Financing Costs The deferred financing costs that are included as a reduction in the net book value of the related liability on our consolidated balance sheets include issuance and other costs related to our debt obligations. These costs are amortized as interest expense using the effective interest method over the life of the related obligations. Fair Value of Financial Instruments The “Fair Value Measurements and Disclosures” Topic of the FASB, or ASC 820, defines fair value, establishes a framework for measuring fair value, and requires certain disclosures about fair value measurements under GAAP. Specifically, this guidance defines fair value based on exit price, or the price that would be received upon the sale of an asset or the transfer of a liability in an orderly transaction between market participants at the measurement date. ASC 820 also establishes a fair value hierarchy that prioritizes and ranks the level of market price observability used in measuring financial instruments. Market price observability is affected by a number of factors, including the type of financial instrument, the characteristics specific to the financial instrument, and the state of the marketplace, including the existence and transparency of transactions between market participants. Financial instruments with readily available quoted prices in active markets generally will have a higher degree of market price observability and a lesser degree of judgment used in measuring fair value. Financial instruments measured and reported at fair value are classified and disclosed based on the observability of inputs used in the determination, as follows: • Level 1: Generally includes only unadjusted quoted prices that are available in active markets for identical financial instruments as of the reporting date. • Level 2: Pricing inputs include quoted prices in active markets for similar instruments, quoted prices in less active or inactive markets for identical or similar instruments where multiple price quotes can be obtained, and other observable inputs, such as interest rates, yield curves, credit risks, and default rates. • Level 3: Pricing inputs are unobservable for the financial instruments and include situations where there is little, if any, market activity for the financial instrument. These inputs require significant judgment or estimation by management of third-parties when determining fair value and generally represent anything that does not meet the criteria of Levels 1 and 2. The estimated value of each asset reported at fair value using Level 3 inputs is determined by an internal committee composed of members of senior management of our Manager, including our Chief Executive Officer, Chief Financial Officer, and other senior officers. Certain of our other assets are reported at fair value, as of quarter-end, During the three months ended June 30, 2020, we recorded an aggregate $69.7 million CECL reserve specifically related to two of our loans receivable, which was unchanged as of September 30, 2021. These two loans have an aggregate outstanding principal balance of $338.7 million, net of cost-recovery proceeds, as of September 30, 2021. The CECL reserve was recorded based on our Manager’s estimation of the fair value of the loan’s underlying collateral as of September 30, 2021. These loans receivable are therefore measured at fair value on a nonrecurring basis using significant unobservable inputs, and are classified as Level 3 assets in the fair value hierarchy. The significant unobservable inputs used to estimate the fair value of these loans receivable include the exit capitalization rate assumption used to forecast the future sale price of the underlying real estate collateral, which ranged from 4.25% to 4.80%. We are also required by GAAP to disclose fair value information about financial instruments, which are not otherwise reported at fair value in our consolidated balance sheet, to the extent it is practicable to estimate a fair value for those instruments. These disclosure requirements exclude certain financial instruments and all non-financial The following methods and assumptions are used to estimate the fair value of each class of financial instruments, for which it is practicable to estimate that value: • Cash and cash equivalents: The carrying amount of cash and cash equivalents approximates fair value. • Loans receivable, net: The fair values of these loans were estimated by our Manager based on a discounted cash flow methodology, taking into consideration various factors including capitalization rates, discount rates, leasing, credit worthiness of major tenants, occupancy rates, availability and cost of financing, exit plan, loan sponsorship, actions of other lenders, and other factors deemed relevant by our Manager. • Debt securities held-to-maturity: • Derivative financial instruments: The fair value of our foreign currency and interest rate contracts was estimated using advice from a third-party derivative specialist, based on contractual cash flows and observable inputs comprising foreign currency rates and credit spreads. • Secured debt, net: The fair value of these instruments was estimated based on the rate at which a similar credit facility would currently be priced. • Securitized debt obligations, net: The fair value of these instruments was estimated by utilizing third-party pricing service providers. In determining the value of a particular investment, pricing service providers may use broker-dealer quotations, reported trades, or valuation estimates from their internal pricing models to determine the reported price. • Asset-specific debt, net: The fair value of these instruments was estimated based on the rate at which a similar agreement would currently be priced. • Term loans, net: The fair value of these instruments was estimated by utilizing third-party pricing service providers. In determining the value of a particular investment, pricing service providers may use broker-dealer quotations, reported trades, or valuation estimates from their internal pricing models to determine the reported price. • Convertible notes, net: Each series of the convertible notes is actively traded and their fair values were obtained using quoted market prices. Income Taxes Our financial results generally do not reflect provisions for current or deferred income taxes on our REIT taxable income. We believe that we operate in a manner that will continue to allow us to be taxed as a REIT and, as a result, we generally do not expect to pay substantial corporate level taxes other than those payable by our taxable REIT subsidiaries. If we were to fail to meet these requirements, we may be subject to federal, state, and local income tax on current and past income, and penalties. Refer to Note 13 for additional information. Stock-Based Compensation Our stock-based compensation consists of awards issued to our Manager and certain individuals employed by an affiliate of our Manager that vest over the life of the awards, as well as deferred stock units issued to certain members of our board of directors. Stock-based compensation expense is recognized for these awards in net income on a variable basis over the applicable vesting period of the awards, based on the value of our class A common stock. Refer to Note 14 for Earnings per Share Basic earnings per share, or Basic EPS, is computed in accordance with the two-class two-class Diluted earnings per share, or Diluted EPS, is determined using the treasury stock method, and is based on the net earnings allocable to our class A common stock, including restricted class A common stock and deferred stock units, divided by the weighted-average number of shares of our class A common stock, including restricted class A common stock and deferred stock units. Refer to Note 11 for additional discussion of earnings per share. Foreign Currency In the normal course of business, we enter into transactions not denominated in United States, or U.S., dollars. Foreign exchange gains and losses arising on such transactions are recorded as a gain or loss in our consolidated statements of operations. In addition, we consolidate entities that have a non-U.S. Non-U.S. non-U.S. Underwriting Commissions and Offering Costs Underwriting commissions and offering costs incurred in connection with common stock offerings are reflected as a reduction of additional paid-in Recent Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04 2020-04. 2020-04 collectively, IBORs, to alternative reference rates. ASU 2020-04 2021-01 2021-01. 2021-01 2020-04 2020-04 2020-04 2020-04 In August 2020, the FASB issued ASU 2020-06 470-20) 815-40): 2020-06. 2020-06 2020-06 2020-06 2020-06, non-cash 2020-06 2020-06 paid-in Reference Rate Reform LIBOR and certain other floating rate benchmark indices to which our floating rate loans and other loan agreements are tied, including, without limitation, the Euro Interbank Offered Rate, or EURIBOR, the Stockholm Interbank Offered Rate, or STIBOR, the Canadian Dollar Offered Rate, or CDOR, and the Australian Bank Bill Swap Reference Rate, or BBSY, or collectively, IBORs, are the subject of recent national, international and regulatory guidance and proposals for reform. On March 5, 2021, the Financial Conduct Authority of the U.K., or FCA, which has statutory powers to require panel banks to contribute to LIBOR where necessary, announced it would cease publication of certain IBORs, including one-week two-month The U.S. Federal Reserve, in conjunction with the Alternative Reference Rates Committee, a steering committee comprised of large U.S. financial institutions, has identified the Secured Overnight Financing Rate, or SOFR, a new index calculated using short-term repurchase agreements backed by Treasury securities, as its preferred alternative rate for USD LIBOR. In the U.K., the Bank of England’s working group on Sterling risk free rates set March 31, 2021 as the target date under which GBP LIBOR may no longer be used as the reference rate for new loan products with maturities after December 31, 2021. Market participants have started to transition to the Sterling Overnight Index Average, or SONIA, in line with guidance from the U.K. regulators. As of September 30, 2021, the floating benchmark rate for the financing provided on the 2020 FL3 and 2020 FL2 CLOs is the 30-day 30-day one-month ive At this time, it is not possible to predict how markets will respond to SOFR, SONIA, or other alternative reference rates as the transition away from USD LIBOR and GBP LIBOR proceeds. Despite the LIBOR transition in other markets, benchmark rate methodologies in Europe, Canada, and Australia have been reformed and rates such as EURIBOR, STIBOR, CDOR, and BBSY may persist as International Organization of Securities Commissions, or IOSCO, compliant reference rates moving forward. However, multi-rate environments may persist in these markets as regulators and working groups have suggested market participants adopt alternative reference rates. Refer to “Part I. Item 1A. Risk Factors—Risks Related to Our Lending and Investment Activities—The expected discontinuation of currently used financial reference rates and use of alternative replacement reference rates may adversely affect net interest income related to our loans and investments or otherwise adversely affect our results of operations, cash flows and the market value of our investments.” of our Annual Report on Form 10-K

Loans Receivable, Net

Loans Receivable, Net	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Loans Receivable, Net	3. LOANS RECEIVABLE, NET The following table details overall statistics for our loans receivable portfolio ($ in thousands): September 30, 2021 December 31, 2020 Number of loans 156 120 Principal balance $ 20,522,560 $ 16,652,824 Net book value $ 20,276,078 $ 16,399,166 Unfunded loan commitments (1) $ 4,220,214 $ 3,160,084 Weighted-average spread (2) + 3.18 % + 3.18 % Weighted-average all-in (2) + 3.51 % + 3.53 % Weighted-average maximum maturity (years) (3) 3.3 3.1 (1) Unfunded commitments will primarily be funded to finance our borrowers’ construction or development of real estate-related assets, capital improvements of existing assets, or lease-related expenditures. These commitments will generally be funded over the term of each loan, subject in certain cases to an expiration date. (2) The weighted-average spread and all-in all-in (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of September 30, 2021, 44% of our loans by principal balance were subject to yield maintenance or other prepayment restrictions and 56% were open to repayment by the borrower without penalty. As of December 31, 2020, 31% of our loans by principal balance were subject to yield maintenance or other prepayment restrictions and 69% were open to repayment by the borrower without penalty. The following table details the index rate floors for our loans receivable portfolio as of September 30, 2021 ($ in thousands): Loans Receivable Principal Balance Index rate floors USD Non-USD (1) Total Fixed rate $ — $ 78,511 $ 78,511 0.00% or no floor (2) 3,265,850 4,912,695 8,178,545 0.01% to 0.24% floor 3,910,133 112,026 4,022,159 0.25% to 0.99% floor 1,363,685 271,616 1,635,301 1.00% or more floor 6,062,597 545,447 6,608,044 Total (3)(4) $ 14,602,265 $ 5,920,295 $ 20,522,560 (1) Includes Euro, British Pound Sterling, Swedish Krona, Australian Dollar, and Canadian Dollar Currencies. (2) Includes $338.7 million of loans accounted for under the cost-recovery method. (3) Excludes investment exposure to $79.2 million subordinate position we own in the $493.3 million 2018 Single Asset Securitization. Refer to Notes 4 and 16 to our consolidated financial statements for further discussion of the 2018 Single Asset Securitization. (4) As of September 30, 2021, the weighted-average index rate floor of our loan portfolio was 0.55%. Excluding 0.0% index rate floors, the weighted-average index rate floor was 0.89%. Activity relating to our loans receivable portfolio was as follows ($ in thousands): Principal Deferred Fees / (1) Net Book Loans receivable, as of December 31, 2020 $ 16,652,824 $ (80,109 ) $ 16,572,715 Loan fundings 7,449,491 — 7,449,491 Loan repayments and sales (3,351,118 ) — (3,351,118 ) Unrealized (loss) gain on foreign currency translation (228,637 ) 1,157 (227,480 ) Deferred fees and other items — (79,971 ) (79,971 ) Amortization of fees and other items — 42,829 42,829 Loans receivable, as of September 30, 2021 $ 20,522,560 $ (116,094 ) $ 20,406,466 CECL reserve (130,388 ) Loans receivable, net, as of September 30, 2021 $ 20,276,078 (1) Other items primarily consist of purchase and sale discounts or premiums, exit fees, and deferred origination expenses. The tables below detail the property type and geographic distribution of the properties securing the loans in our portfolio ($ in thousands): September 30, 2021 Property Type Number of Net Book Total Loan (1)(2) Percentage of Office 65 $ 10,239,432 $ 10,940,778 50% Multifamily 56 4,465,938 4,494,065 21 Hospitality 18 2,777,827 2,879,888 13 Industrial 5 894,865 901,211 4 Retail 6 770,045 773,491 4 Life Sciences 2 407,595 413,209 2 Other 4 850,764 1,117,525 6 Total loans receivable 156 $ 20,406,466 $ 21,520,167 100% CECL reserve (130,388 ) Loans receivable, net $ 20,276,078 Geographic Location Number of Net Book Total Loan (1)(2) Percentage of United States Northeast 26 $ 4,463,202 $ 4,491,804 21% West 32 3,548,756 4,126,256 19 Southeast 33 3,425,624 3,618,296 17 Southwest 24 1,786,470 1,796,817 8 Midwest 10 1,201,663 1,205,877 6 Northwest 2 94,670 94,963 — Subtotal 127 14,520,385 15,334,013 71 International United Kingdom 14 1,754,872 1,999,180 9 Spain 4 1,448,355 1,455,967 7 Ireland 1 1,233,286 1,237,547 6 Sweden 1 564,277 569,529 3 Australia 2 175,786 176,144 1 Canada 2 66,881 66,864 — Other Europe 5 642,624 680,923 3 Subtotal 29 5,886,081 6,186,154 29 Total loans receivable 156 $ 20,406,466 $ 21,520,167 100% CECL reserve (130,388 ) Loans receivable, net $ 20,276,078 (1) In certain instances, we finance our loans through the non-recourse non-consolidated (2) Excludes investment exposure to the $493.3 million 2018 Single Asset Securitization. See Note 4 for details of the subordinate position we own in the 2018 Single Asset Securitization. December 31, 2020 Property Type Number of Net Book Total Loan (1)(2) Percentage of Office 58 $ 9,834,509 $ 10,303,895 58% Hospitality 14 2,295,255 2,369,454 14 Multifamily 31 1,788,149 1,862,667 11 Industrial 6 673,912 675,344 4 Retail 4 538,702 551,243 3 Life Sciences 1 146,290 147,763 1 Other 6 1,295,898 1,544,255 9 Total loans receivable 120 $ 16,572,715 $ 17,454,621 100% CECL reserve (173,549 ) Loans receivable, net $ 16,399,166 Geographic Location Number of Net Book Total Loan (1)(2) Percentage of United States Northeast 24 $ 4,050,732 $ 4,069,712 23% West 27 2,942,126 3,413,089 20 Southeast 25 2,624,701 2,707,080 16 Midwest 8 973,702 976,693 6 Southwest 9 597,100 598,813 3 Northwest 1 15,404 15,413 — Subtotal 94 11,203,765 11,780,800 68 International United Kingdom 13 1,816,901 2,066,390 12 Ireland 1 1,309,443 1,317,846 8 Spain 2 1,247,162 1,252,080 7 Australia 2 259,126 259,788 1 Canada 3 82,185 82,262 — Other Europe 5 654,133 695,455 4 Subtotal 26 5,368,950 5,673,821 32 Total loans receivable 120 $ 16,572,715 $ 17,454,621 100% CECL reserve (173,549 ) Loans receivable, net $ 16,399,166 (1) In certain instances, we finance our loans through the non-recourse non-consolidated (2) Excludes investment exposure to the $735.5 million 2018 Single Asset Securitization. See Note 4 for details of the subordinate position we own in the 2018 Single Asset Securitization. Loan Risk Ratings As further described in Note 2, our Manager evaluates our loan portfolio on a quarterly basis. In conjunction with our quarterly loan portfolio review, our Manager assesses the risk factors of each loan, and assigns a risk rating based on several factors. Factors considered in the assessment include, but are not limited to, risk of loss, current LTV, debt yield, collateral performance, structure, exit plan, and sponsorship. Loans are rated “1” (less risk) through “5” (greater risk), which ratings are defined in Note 2. The following table allocates the principal balance and net book value of our loans receivable based on our internal risk ratings ($ in thousands): September 30, 2021 December 31, 2020 Risk Rating Number of Loans Net Book Value Total Loan Exposure (1)(2) Number of Loans Net Book Value Total Loan Exposure (1)(2) 1 8 $ 931,330 $ 931,831 8 $ 777,163 $ 778,283 2 27 4,800,884 4,836,029 17 2,513,848 2,528,835 3 110 12,060,623 13,129,870 79 9,911,914 10,763,496 4 9 2,276,394 2,283,701 14 3,032,593 3,045,309 5 2 337,235 338,736 2 337,197 338,698 Total loans receivable 156 $ 20,406,466 $ 21,520,167 120 $ 16,572,715 $ 17,454,621 CECL reserve (130,388 ) (173,549 ) Loans receivable, net $ 20,276,078 $ 16,399,166 (1) In certain instances, we finance our loans through the non-recourse non-consolidated (2) Excludes investment exposure to the 2018 Single Asset Securitization of $493.3 million and $735.5 million as of September 30, 2021 and December 31, 2020, respectively. See Note 4 for details of the subordinate position we own in the 2018 Single Asset Securitization. The weighted-average risk rating of our total loan exposure was 2.8 and 3.0 as of September 30, 2021 and December 31, 2020, respectively. The decrease in risk rating reflects the ongoing market recovery from COVID-19 Current Expected Credit Loss Reserve The CECL reserve required under GAAP reflects our current estimate of potential credit losses related to the loans and debt securities included in our consolidated balance sheets. Refer to Note 2 for further discussion of our CECL reserve. The following table presents the activity in our loans receivable CECL reserve by investment pool for the three and nine months ended September 30, 2021 and 2020 ($ in thousands): U.S. Loans Non-U.S. Loans Unique Loans Impaired Loans Total Loans Receivable, Net CECL reserve as of December 31, 2020 $ 42,995 $ 27,734 $ 33,159 $ 69,661 $ 173,549 Increase (decrease) in CECL reserve 1,539 (3,134 ) 146 — (1,449 ) CECL reserve as of March 31, 2021 $ 44,534 $ 24,600 $ 33,305 $ 69,661 $ 172,100 Decrease in CECL reserve (26,861 ) (15,771 ) (523 ) — (43,155 ) CECL reserve as of June 30, 2021 $ 17,673 $ 8,829 $ 32,782 $ 69,661 $ 128,945 Increase (decrease) in CECL reserve 3,253 (283 ) (1,527 ) — 1,443 CECL reserve as of September 30, 2021 $ 20,926 $ 8,546 $ 31,255 $ 69,661 $ 130,388 CECL reserve as of December 31, 2019 $ — $ — $ — $ — $ — Initial CECL reserve on January 1, 2020 8,955 3,631 1,356 — 13,942 Increase in CECL reserve 55,906 18,194 24,652 — 98,752 CECL reserve as of March 31, 2020 $ 64,861 $ 21,825 $ 26,008 $ — $ 112,694 (Decrease) increase in CECL reserve (3,457 ) (2,080 ) 1,232 69,661 65,356 CECL reserve as of June 30, 2020 $ 61,404 $ 19,745 $ 27,240 $ 69,661 $ 178,050 (Decrease) increase in CECL reserve (10,762 ) 7,035 2,703 — (1,024 ) CECL reserve as of September 30, 2020 $ 50,642 $ 26,780 $ 29,943 $ 69,661 $ 177,026 Our initial CECL reserve of $13.9 million against our loans receivable portfolio, recorded on January 1, 2020, is reflected as a direct charge to retained earnings on our consolidated statements of changes in equity; however subsequent changes to the CECL reserve are recognized through net income on our consolidated statements of operations. During the three and nine months ended September 30, 2021, we recorded an increase of $1.4 million and a decrease of $43.2 million, respectively, in the CECL reserve against our loans receivable portfolio, bringing our total reserve to $130.4 million as of September 30, 2021. The increase in the CECL reserve during the three months ended September 30, 2021 is primarily due to an increase in the size of our loans receivable portfolio during the three months ended September 30, 2021. The decrease in the CECL reserve during the nine months ended September 30, 2021 reflects the ongoing market recovery from COVID-19 COVID-19. During 2020 and 2021, we entered into loan modifications related to a multifamily asset in New York City, which are classified as troubled debt restructurings under GAAP. These modifications included, among other changes, a reduction in the loan’s contractual interest payments and an extension of the loan’s maturity date. During the three months ended June 30, 2020, we recorded a $14.8 million During 2020, we entered into a loan modification related to a hospitality asset in New York City, which is classified as a troubled debt restructuring under GAAP. This modification included, among other changes, a reduction in the loan’s contractual interest payments and an extension of the loan’s maturity date. During the three months ended June 30, 2020, we recorded a $54.9 million CECL reserve on this loan, which was unchanged as of September 30, 2021. This loan has an outstanding principal balance of $286.3 million, net of cost-recovery proceeds, as of September 30, 2021. The CECL reserve was recorded based on our Manager’s estimation of the fair value of the loan’s underlying collateral as of September 30, 2021. As of July 1, 2020, the income accrual was suspended on the two loans detailed above, which had an aggregate outstanding principal balance of $338.7 million, as of September 30, 2021. No income was recorded on these loans subsequent to July 1, 2020. Our primary credit quality indicator is our risk ratings, which are further discussed above. The following tables present the net book value of our loan portfolio as of September 30, 2021 and December 31, 2020, respectively, by year of origination, investment pool, and risk rating ($ in thousands): Net Book Value of Loans Receivable by Year of Origination (1)(2) As of September 30, 2021 Risk Rating 2021 2020 2019 2018 2017 Prior Total U.S. loans 1 $ — $ 43,745 $ 696,764 $ — $ 66,188 $ — $ 806,697 2 694,114 — 586,976 887,935 391,740 81,256 2,642,021 3 4,979,207 830,399 1,844,466 1,522,591 602,976 269,127 10,048,766 4 — — 96,494 540,766 63,365 51,923 752,548 5 — — — — — — — Total U.S. loans $ 5,673,321 $ 874,144 $ 3,224,700 $ 2,951,292 $ 1,124,269 $ 402,306 $ 14,250,032 Non-U.S. 1 $ — $ — $ 34,877 $ — $ 89,756 $ — $ 124,633 2 564,277 100,126 1,383,692 — — 110,768 2,158,863 3 455,534 — 907,728 393,573 — — 1,756,835 4 — — 346,071 — — — 346,071 5 — — — — — — — Total Non-U.S. $ 1,019,811 $ 100,126 $ 2,672,368 $ 393,573 $ 89,756 $ 110,768 $ 4,386,402 Unique loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — — 196,073 — 58,949 255,022 4 — — 321,156 856,619 — — 1,177,775 5 — — — — — — — Total unique loans $ — $ — $ 321,156 $ 1,052,692 $ — $ 58,949 $ 1,432,797 Impaired loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — — — — — — 4 — — — — — — — 5 — — — 284,808 — 52,427 337,235 Total impaired loans $ — $ — $ — $ 284,808 $ — $ 52,427 $ 337,235 Total loans receivable 1 $ — $ 43,745 $ 731,641 $ — $ 155,944 $ — $ 931,330 2 1,258,391 100,126 1,970,668 887,935 391,740 192,024 4,800,884 3 5,434,741 830,399 2,752,194 2,112,237 602,976 328,076 12,060,623 4 — — 763,721 1,397,385 63,365 51,923 2,276,394 5 — — — 284,808 — 52,427 337,235 Total loans receivable $ 6,693,132 $ 974,270 $ 6,218,224 $ 4,682,365 $ 1,214,025 $ 624,450 $ 20,406,466 CECL reserve (130,388 ) Loans receivable, net $ 20,276,078 (1) Date loan was originated or acquired by us. Origination dates are subsequently updated to reflect material loan modifications. (2) Excludes the $77.6 million net book value of our held-to-maturity Net Book Value of Loans Receivable by Year of Origination (1)(2) As of December 31, 2020 Risk Rating 2020 2019 2018 2017 2016 Prior Total U.S. loans 1 $ — $ 231,796 $ 253,674 $ 43,906 $ 17,009 $ — $ 546,385 2 — 282,017 1,172,168 757,138 79,848 222,677 2,513,848 3 781,595 2,391,297 1,672,897 1,134,288 227,466 220,644 6,428,187 4 65,978 170,541 1,055,142 63,293 105,380 — 1,460,334 5 — — — — — — — Total U.S. loans $ 847,573 $ 3,075,651 $ 4,153,881 $ 1,998,625 $ 429,703 $ 443,321 $ 10,948,754 Non-U.S. 1 $ — $ — $ 136,021 $ 94,757 $ — $ — $ 230,778 2 — — — — — — — 3 105,300 2,526,225 479,512 — 113,653 — 3,224,690 4 — 256,494 — — — — 256,494 5 — — — — — — — Total Non-U.S. $ 105,300 $ 2,782,719 $ 615,533 $ 94,757 $ 113,653 $ — $ 3,711,962 Unique loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — 198,433 — — 60,604 259,037 4 — 325,097 990,668 — — — 1,315,765 5 — — — — — — — Total unique loans $ — $ 325,097 $ 1,189,101 $ — $ — $ 60,604 $ 1,574,802 Impaired loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — — — — — — 4 — — — — — — — 5 — — 284,809 — — 52,388 337,197 Total impaired loans $ — $ — $ 284,809 $ — $ — $ 52,388 $ 337,197 Total loans receivable 1 $ — $ 231,796 $ 389,695 $ 138,663 $ 17,009 $ — $ 777,163 2 — 282,017 1,172,168 757,138 79,848 222,677 2,513,848 3 886,895 4,917,522 2,350,842 1,134,288 341,119 281,248 9,911,914 4 65,978 752,132 2,045,810 63,293 105,380 — 3,032,593 5 — — 284,809 — — 52,388 337,197 Total loans receivable $ 952,873 $ 6,183,467 $ 6,243,324 $ 2,093,382 $ 543,356 $ 556,313 $ 16,572,715 CECL reserve (173,549 ) Loans receivable, net $ 16,399,166 (1) Date loan was originated or acquired by us. Origination dates are subsequently updated to reflect material loan modifications. (2) Excludes the $75.7 million net book value of our held-to-maturity Multifamily Joint Venture As discussed in Note 2, we entered into a Multifamily Joint Venture in April 2017. As of September 30, 2021 and December 31, 2020, our Multifamily Joint Venture held $817.9 million and $484.8 million of loans, respectively, which are included in the loan disclosures above. Refer to Note 2 for additional discussion of our Multifamily Joint Venture.

Other Assets and Liabilities

Other Assets and Liabilities	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Other Assets and Liabilities	4. OTHER ASSETS AND LIABILITIES Other Assets The following table details the components of our other assets ($ in thousands): September 30, 2021 December 31, 2020 Accrued interest receivable $ 78,689 $ 66,757 Debt securities held-to-maturity (1) 77,916 77,445 CECL reserve (280 ) (1,723 ) Debt securities held-to-maturity, 77,636 75,722 Derivative assets 35,858 522 2021 FL4 CLO restricted cash (2) 25,000 — Loan portfolio payments held by servicer (3) 766 73,224 Prepaid expenses 43 973 Collateral deposited under derivative agreements — 51,050 Prepaid taxes — 376 Other 622 1,195 Total $ 218,614 $ 269,819 (1) Represents the subordinate position we own in the 2018 Single Asset Securitization, which held aggregate loan assets of $493.3 million and $735.5 million as of September 30, 2021 and December 31, 2020, respectively, with a yield to full maturity of L+10.0% and a maximum maturity date of June 9, 2025, assuming all extension options are exercised by the borrower. Refer to Note 16 for additional discussion. (2) Represents $25.0 million of restricted cash held by our 2021 FL4 collateralized loan obligation that can be used to acquire and finance additional assets for up to six months from the date of closing. (3) Represents loan principal and interest payments held by our third-party loan servicer as of the balance sheet date which were remitted to us during the subsequent remittance cycle. Current Expected Credit Loss Reserve The CECL reserve required under GAAP reflects our current estimate of potential credit losses related to the loans and debt securities included in our consolidated balance sheets. Refer to Note 2 for further discussion of our CECL reserve. The following table presents the activity in our debt securities CECL reserve by investment pool for the three and nine months ended September 30, 2021 and 2020 ($ in thousands): Debt Securities Held-To-Maturity CECL reserve as of December 31, 2020 $ 1,723 Decrease in CECL reserve (834 ) CECL reserve as of March 31, 2021 $ 889 Decrease in CECL reserve (767 ) CECL reserve as of June 30, 2021 $ 122 Increase in CECL reserve 158 CECL reserve as of September 30, 2021 $ 280 CECL reserve as of December 31, 2019 $ — Initial CECL reserve on January 1, 2020 445 Increase in CECL reserve 4,677 CECL reserve as of March 31, 2020 $ 5,122 Decrease in CECL reserve (1,003 ) CECL reserve as of June 30, 2020 $ 4,119 Decrease in CECL reserve (2,086 ) CECL reserve as of September 30, 2020 $ 2,033 Our initial CECL reserve of $445,000 against our debt securities held-to-maturity, held-to-maturity, held-to-maturity, COVID-19. Other Liabilities The following table details the components of our other liabilities ($ in thousands): September 30, 2021 December 31, 2020 Accrued dividends payable $ 97,350 $ 91,004 Accrued interest payable 25,772 20,548 Accrued management and incentive fees payable 19,342 19,158 Accounts payable and other liabilities 11,080 2,671 Current expected credit loss reserve for unfunded loan commitments (1) 5,203 10,031 Derivative liabilities 355 58,915 Secured debt repayments pending servicer remittance (2) 322 — Total $ 159,424 $ 202,327 (1) Represents the CECL reserve related to our unfunded loan commitments. See Note 2 for further discussion of the CECL reserve. (2) Represents pending transfers from our third-party loan servicer that were remitted to our banking counterparties during the subsequent remittance cycle. Current Expected Credit Loss Reserve for Unfunded Loan Commitments As of September 30, 2021, we had aggregate unfunded loan commitments of $4.2 billion across 108 loans receivable. The expected credit losses over the contractual period of our loans are subject to the obligation to extend credit through our unfunded loan commitments. See Note 2 for further discussion of the CECL reserve related to our unfunded loan commitments, and Note 18 for further discussion of our unfunded loan commitments. The following table presents the activity in the CECL reserve related to our unfunded loan commitments by investment pool for the three and nine months ended September 30, 2021 and 2020 ($ in thousands): U.S. Loans Non-U.S. Loans Unique Loans Impaired Loans Total Unfunded Loan Commitments CECL reserve as of December 31, 2020 $ 6,953 $ 2,994 $ 84 $ — $ 10,031 Increase (decrease) in CECL reserve 216 778 (4 ) — 990 CECL reserve as of March 31, 2021 $ 7,169 $ 3,772 $ 80 $ — $ 11,021 Decrease in CECL reserve (4,315 ) (2,632 ) (37 ) — (6,984 ) CECL reserve as of June 30, 2021 $ 2,854 $ 1,140 $ 43 $ — $ 4,037 Increase (decrease) in CECL reserve 566 643 (43 ) — 1,166 CECL reserve as of September 30, 2021 $ 3,420 $ 1,783 $ — $ — $ 5,203 CECL reserve as of December 31, 2019 $ — $ — $ — $ — $ — Initial CECL reserve on January 1, 2020 2,801 453 9 — 3,263 Increase in CECL reserve 16,992 2,219 62 — 19,273 CECL reserve as of March 31, 2020 $ 19,793 $ 2,672 $ 71 $ — $ 22,536 (Decrease) increase in CECL reserve (6,957 ) (594 ) 17 — (7,534 ) CECL reserve as of June 30, 2020 $ 12,836 $ 2,078 $ 88 $ — $ 15,002 (Decrease) increase in CECL reserve (3,657 ) 732 (20 ) — (2,945 ) CECL reserve as of September 30, 2020 $ 9,179 $ 2,810 $ 68 $ — $ 12,057 Our initial CECL reserve of $3.3 million against our unfunded loan commitments, recorded on January 1, 2020, is reflected as a direct charge to retained earnings on our consolidated statements of changes in equity; however subsequent changes to the CECL reserve are recognized through net income on our consolidated statements of operations. During the three and nine months ended September 30, 2021, we recorded an increase of $1.2 million and a decrease of $4.8 million, respectively, in the CECL reserve against our unfunded loan commitments, bringing our total reserve to $5.2 million as of September 30, 2021. The increase in the CECL reserve against our unfunded loan commitments during the three months ended September 30, 2021 is primarily due to an increase in the size of our loans receivable portfolio during the three months ended September 30, 2021. The decrease in the CECL reserve during the nine months ended September 30, 2021 reflects the ongoing market recovery from COVID-19 COVID-19.

Secured Debt, Net

Secured Debt, Net	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Secured Debt, Net	5. SECURED DEBT, NET Our secured debt includes our secured credit facilities and acquisition facility. During the three months ended September 30, 2021, we obtained approval for $2.8 billion of new borrowings against $3.5 billion of collateral assets from nine Secured Debt Borrowings Outstanding September 30, 2021 December 31, 2020 Secured credit facilities $ 11,188,855 $ 7,896,863 Acquisition facility — — Total secured debt $ 11,188,855 $ 7,896,863 Deferred financing costs (1) (18,525 ) (16,327 ) Net book value of secured debt $ 11,170,330 $ 7,880,536 (1) Costs incurred in connection with our secured debt are recorded on our consolidated balance sheet when incurred and recognized as a component of interest expense over the life of each related facility. Secured Credit Facilities Our secured credit facilities are bilateral agreements we use to finance diversified pools of senior loan collateral with sufficient flexibility to accommodate our investment and asset management strategy. The facilities are uniformly structured to provide currency, index, and term-matched financing without capital markets based mark-to-market The following table details our secured credit facilities as of September 30, 2021 ($ in thousands): September 30, 2021 Wtd Avg. Wtd Avg. Recourse Limitation Currency Lenders (1) Borrowings Maturity (2) Loan Count Collateral (3) Maturity (4) Wtd. Avg. Range USD 12 $ 7,022,125 5/5/2025 114 $ 9,557,168 5/1/2025 29% 25% - 100% EUR 6 2,369,013 7/26/2024 10 3,150,165 7/4/2024 48% 25% - 100% GBP 6 1,163,414 10/22/2024 12 1,739,121 11/9/2024 26% 25% - 50% Others (5) 4 634,303 6/17/2025 5 812,537 5/28/2025 27% 25% - 100% Total 12 $ 11,188,855 2/17/2025 141 $ 15,258,991 2/10/2025 32% 25% - 100% (1) Represents the number of lenders with fundings advanced in each respective currency, as well as the total number of facility lenders. (2) Based on the earlier of (i) the maximum maturity date of each secured credit facility, or (ii) the maximum maturity date of the collateral loans. (3) Represents the principal balance of the collateral assets. (4) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. (5) Includes Swedish Krona, Australian Dollar, and Canadian Dollar currencies. The availability of funding under our secured credit facilities is based on the amount of approved collateral, which collateral is proposed by us in our discretion and approved by the respective counterparty in its discretion, resulting in a mutually agreed collateral portfolio construction. Certain structural elements of our secured credit facilities, including the limitation on recourse to us and facility economics are influenced by the specific collateral portfolio construction of each facility, and therefore vary within and among the facilities. The following tables detail the spread of our secured credit facilities as of September 30, 2021 and December 31, 2020 ($ in thousands): Nine Months Ended September 30, 2021 Spread (1) New Financings (2) Total Borrowings Wtd. Avg. All-in Cost (1)(3)(4) Collateral (5) Wtd. Avg. All-in Yield (1)(6) Net Interest (7) + 1.50% or less $ 3,065,115 $ 6,288,807 + 1.54 % $ 8,176,251 + 3.09 % + 1.55 % + 1.51% to + 1.75% 1,268,796 2,780,867 + 1.88 % 3,851,597 + 3.40 % + 1.52 % + 1.76% to + 2.00% 479,767 897,258 + 2.08 % 1,253,906 + 3.95 % + 1.87 % + 2.01% or more 465,872 1,221,923 + 2.42 % 1,977,237 + 4.42 % + 2.00 % Total $ 5,279,550 $ 11,188,855 + 1.77 % $ 15,258,991 + 3.41 % + 1.64 % Year Ended December 31, 2020 Spread (1) New Financings (2) Total Borrowings Wtd. Avg. All-in Cost (1)(3)(4) Collateral (5) Wtd. Avg. All-in Yield (1)(6) Net Interest Margin (7) + 1.50% or less $ 376,085 $ 4,192,280 + 1.59 % $ 6,338,626 + 3.09 % + 1.50 % + 1.51% to + 1.75% 172,447 1,945,692 + 1.95 % 2,975,581 + 3.43 % + 1.48 % + 1.76% to + 2.00% 215,056 926,666 + 2.06 % 1,212,546 + 3.83 % + 1.77 % + 2.01% or more 134,928 832,225 + 2.49 % 1,514,154 + 4.34 % + 1.85 % Total $ 898,516 $ 7,896,863 + 1.83 % $ 12,040,907 + 3.40 % + 1.57 % (1) The spread, all-in all-in (2) Represents borrowings outstanding as of September 30, 2021 and December 31, 2020, respectively, for new financings during the nine months ended September 30, 2021 and year ended December 31, 2020, respectively, based on the date collateral was initially pledged to each credit facility. (3) In addition to spread, the cost includes the associated deferred fees and expenses related to the respective borrowings. (4) Represents the weighted-average all-in (5) Represents the principal balance of the collateral assets. (6) In addition to cash coupon, all-in (7) Represents the difference between the weighted-average all-in all-in Our secured credit facilities generally permit us to increase or decrease the amount advanced against the pledged collateral in our discretion within certain maximum/minimum amount and frequency limitations. As of September 30, 2021, there was an aggregate $306.2 million available to be drawn at our discretion under our credit facilities. Acquisition Facility We have a $250.0 million full recourse secured credit facility that is designed to finance eligible first mortgage originations for up to nine months as a bridge to term financing without obtaining discretionary lender approval. The cost of borrowing under the facility is variable, dependent on the type of loan collateral, and its maturity date is April 4, 2023. During the nine months ended September 30, 2021, we had no borrowings under the acquisition facility and we recorded interest expense of $925,000, including $262,000 of amortization of deferred fees and expenses. As of September 30, 2021, we had one asset pledged to our acquisition facility and there was an aggregate $146.3 million available to be drawn at our discretion. During the nine months ended December 31, 2020, we had no borrowings under the acquisition facility and we recorded interest expense of $1.1 million, including $411,000 of amortization of deferred fees and expenses. Financial Covenants We are subject to the following financial covenants related to our secured debt: (i) our ratio of earnings before interest, taxes, depreciation, and amortization, or EBITDA, to fixed charges, as defined in the agreements, shall be not less than 1.4 to 1.0; (ii) our tangible net worth, as defined in the agreements, shall not be less than $3.2 billion as of each measurement date plus 75% of the net cash proceeds of future equity issuances subsequent to September 30, 2021; (iii) cash liquidity shall not be less than the greater of (x) $10.0 million or (y) no more than 5% of our recourse indebtedness; and (iv) our indebtedness shall not exceed 83.33% of our total assets. As of September 30, 2021 and December 31, 2020, we were in compliance with these covenants.

Securitized Debt Obligations, N

Securitized Debt Obligations, Net	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Securitized Debt Obligations, Net	6. SECURITIZED DEBT OBLIGATIONS, NET We have financed certain pools of our loans through collateralized loan obligations, which include the 2021 FL4 CLO, 2020 FL3 CLO, 2020 FL2 CLO, and 2017 FL1 CLO or collectively, the CLOs. We have also financed one of our loans through a single asset securitization vehicle, or the 2017 Single Asset Securitization. The CLOs and the 2017 Single Asset Securitization are consolidated in our financial statements and have issued securitized debt obligations that are non-recourse The following tables detail our securitized debt obligations ($ in thousands): September 30, 2021 Securitized Debt Obligations Count Principal Balance Book Value Wtd. Avg. (1) (2) Term (3) 2021 FL4 Collateralized Loan Obligation Collateral assets 35 $ 1,000,000 $ 1,000,000 + 3.41 % July 2024 Financing provided 1 803,750 796,864 + 1.65 % May 2038 2020 FL3 Collateralized Loan Obligation Collateral assets 21 1,000,000 1,000,000 + 3.02 % April 2024 Financing provided (2) 1 808,750 803,378 + 2.10 % November 2037 2020 FL2 Collateralized Loan Obligation Collateral assets 24 1,500,000 1,500,000 + 3.10 % March 2024 Financing provided (2) 1 1,243,125 1,235,807 + 1.45 % February 2038 Total Collateral assets 80 $ 3,500,000 $ 3,500,000 + 3.17 % Financing provided (4) 3 $ 2,855,625 $ 2,836,049 + 1.69 % (1) In addition to cash coupon, all-in (2) The weighted-average all-in 30-day 30-day one-month (3) Loan term represents weighted-average final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitizations. (4) During the three and nine months ended September 30, 2021, we recorded $10.7 million and $35.2 million, respectively, of interest expense related to our securitized debt obligations. December 31, 2020 Securitized Debt Obligations Count Principal Book Value Wtd. Avg. (1) (2) Term (3) 2020 FL3 Collateralized Loan Obligation Collateral assets 25 $ 1,000,000 $ 1,000,000 + 3.09 % February 2024 Financing provided 1 808,750 800,993 + 2.08 % November 2037 2020 FL2 Collateralized Loan Obligation Collateral assets 31 1,500,000 1,500,000 + 3.17 % January 2024 Financing provided 1 1,243,125 1,233,464 + 1.44 % February 2038 2017 FL1 Collateralized Loan Obligation Collateral assets 15 666,334 666,334 + 3.39 % January 2023 Financing provided 1 483,834 483,113 + 1.83 % June 2035 2017 Single Asset Securitization Collateral assets (4) 1 619,194 618,766 + 3.57 % June 2023 Financing provided 1 404,929 404,929 + 1.63 % June 2033 Total Collateral assets 72 $ 3,785,528 $ 3,785,100 + 3.25 % Financing provided (5) 4 $ 2,940,638 $ 2,922,499 + 1.70 % (1) In addition to cash coupon, all-in (2) The weighted-average all-in (3) Loan term represents weighted-average final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitizations. (4) The collateral assets for the 2017 Single Asset Securitization include the total loan amount, of which we securitized $500.0 million. (5) During the three and nine months ended September 30, 2020, we recorded $9.1 million and $31.8 million, respectively, of interest expense related to our securitized debt obligations.

Asset-Specific Debt, Net

Asset-Specific Debt, Net	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Asset-Specific Debt, Net	7. ASSET-SPECIFIC DEBT, NET The following tables detail our asset-specific debt ($ in thousands): September 30, 2021 Asset-Specific Debt Count Principal Balance Book Value Wtd. Avg. Yield/Cost (1) Wtd. Avg. Term (2) Collateral assets 3 $ 436,562 $ 424,650 + 4.34 % Dec. 2024 Financing provided 3 $ 328,068 $ 320,895 + 3.13 % Dec. 2024 December 31, 2020 Asset-Specific Debt Count Principal Balance Book Value Wtd. Avg. Yield/Cost (1) Wtd. Avg. Term (2) Collateral assets 4 $ 512,794 $ 499,085 + 4.65 % Oct. 2023 Financing provided 4 $ 399,699 $ 391,269 + 3.48 % Oct. 2023 (1) These floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) The weighted-average term is determined based on the maximum maturity of the corresponding loans, assuming all extension options are exercised by the borrower. Each of our asset-specific debt is term-matched to the corresponding collateral loans.

Term Loans, Net

Term Loans, Net	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Term Loans, Net	8. TERM LOANS, NET During the nine months ended September 30, 2021, we (i) increased our borrowings under our B-2 B-1 As of September 30, 2021, the following senior term loan facilities, or Term Loans, were outstanding ($ in thousands): Term Loans Face Value Interest Rate (1) All-in Cost (1)(2) Maturity B-1 $ 932,256 + 2.25 % + 2.53 % April 23, 2026 B-2 $ 420,450 + 2.75 % + 3.42 % April 23, 2026 (1) The B-2 (2) Includes issue discount and transaction expenses that are amortized through interest expense over the life of the Term Loans. The Term Loans are partially amortizing, with an amount equal to 1.0% per annum of the aggregate principal balance due in quarterly installments. The issue discount and transaction expenses on the B-1 B-1 B-2 B-2 The following table details the net book value of our Term Loans on our consolidated balance sheets ($ in thousands): September 30, 2021 December 31, 2020 Face value $ 1,352,706 $ 1,062,766 Unamortized discount (9,748 ) (9,807 ) Deferred financing costs (13,321 ) (11,255 ) Net book value $ 1,329,637 $ 1,041,704 The guarantee under our Term Loans contains the financial covenant that our indebtedness shall not exceed 83.33% of our total assets. As of September 30, 2021 and December 31, 2020, we were in compliance with this covenant. Refer to Note 2 for additional discussion of our accounting policies for the Term Loans.

Convertible Notes, Net

Convertible Notes, Net	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Convertible Notes, Net	9. CONVERTIBLE NOTES, NET As of September 30, 2021, the following convertible senior notes, or Convertible Notes, were outstanding ($ in thousands): Convertible Notes Face Value Interest Rate All-in Cost (1) Conversion Rate (2) Maturity May 2017 $ 402,500 4.38 % 4.85 % 28.0324 May 5, 2022 March 2018 $ 220,000 4.75 % 5.33 % 27.6052 March 15, 2023 (1) Includes issuance costs that are amortized through interest expense over the life of the Convertible Notes using the effective interest method. (2) Represents the shares of class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to a conversion price of $35.67 and $36.23 per share of class A common stock, respectively, for the May 2017 and March 2018 convertible notes. The cumulative dividend threshold as defined in the respective May 2017 and March 2018 convertible notes supplemental indentures have not been exceeded as of September 30, 2021. The Convertible Notes are convertible at the holders’ option into shares of our class A common stock, only under specific circumstances, prior to the close of business on January 31, 2022 and December 14, 2022 for the May 2017 and March 2018 convertible notes, respectively, at the applicable conversion rate in effect on the conversion date.​​​​​​​ Thereafter, the Convertible Notes are convertible at the option of the holder at any time until the second scheduled trading day immediately preceding the maturity date. We may not redeem the Convertible Notes prior to maturity. The last reported sale price of our class A common stock of $30.32 on September 30, 2021 was less than the per share conversion price of the May 2017 and March 2018 convertible notes. We have the intent and ability to settle each series of the Convertible Notes in cash and, as a result, the potential conversion of the Convertible Notes did not have any impact on our diluted earnings per share. Upon our issuance of the May 2017 convertible notes, we recorded a $979,000 discount based on the implied value of the conversion option and an assumed effective interest rate of 4.57%, as well as $8.4 million of issue discount and issuance costs. Including the amortization of the discount and issuance costs, our total cost of the May 2017 convertible notes issuance is 4.91% per annum. Upon our issuance of the March 2018 convertible notes, we recorded a $1.5 million discount based on the implied value of the conversion option and an assumed effective interest rate of 5.25%, as well as $5.2 million of issue discount and issuance costs. Including the amortization of the discount and issuance costs, our total cost of the March 2018 convertible notes issuance is 5.49% per annum. The following table details the net book value of our Convertible Notes on our consolidated balance sheets ($ in thousands): September 30, 2021 December 31, 2020 Face value $ 622,500 $ 622,500 Unamortized discount (3,301 ) (5,715 ) Deferred financing costs (214 ) (396 ) Net book value $ 618,985 $ 616,389 The following table details our interest expense related to the Convertible Notes ($ in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2021 2020 2021 2020 Cash coupon $ 7,015 $ 7,015 $ 21,045 $ 21,045 Discount and issuance cost amortization 873 831 2,595 2,470 Total interest expense $ 7,888 $ 7,846 $ 23,640 $ 23,515 Accrued interest payable for the Convertible Notes was $7.8 million and $6.0 million as of September 30, 2021 and December 31, 2020, respectively. Refer to Note 2 for additional discussion of our accounting policies for the Convertible Notes.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	10. DERIVATIVE FINANCIAL INSTRUMENTS The sole objective of our use of derivative financial instruments is to minimize the risks and/or costs associated with our investments and/or financing transactions. These derivatives may or may not qualify as net investment, cash flow, or fair value hedges under the hedge accounting requirements of ASC 815 – “Derivatives and Hedging.” Derivatives not designated as hedges are not speculative and are used to manage our exposure to interest rate movements and other identified risks. Refer to Note 2 for additional discussion of the accounting for designated and non-designated The use of derivative financial instruments involves certain risks, including the risk that the counterparties to these contractual arrangements do not perform as agreed. To mitigate this risk, we only enter into derivative financial instruments with counterparties that have appropriate credit ratings and are major financial institutions with which we and our affiliates may also have other financial relationships. Cash Flow Hedges of Interest Rate Risk Certain of our transactions expose us to interest rate risks, which include a fixed versus floating rate mismatch between our assets and liabilities. We use derivative financial instruments, which includes interest rate caps, and may also include interest rate swaps, options, floors, and other interest rate derivative contracts, to hedge interest rate risk. The following tables detail our outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk (notional amount in thousands): September 30, 2021 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Caps 1 C$ 21,020 1.0 % CDOR 0.2 December 31, 2020 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Caps 2 C$ 38,293 1.0 % CDOR 0.8 Amounts reported in accumulated other comprehensive income (loss) related to derivatives will be reclassified to interest expense as interest payments are made on our floating rate debt. During the twelve months following September 30, 2021, we estimate that an additional $3,000 will be reclassified from accumulated other comprehensive income (loss) as an increase to interest expense. Net Investment Hedges of Foreign Currency Risk Certain of our international investments expose us to fluctuations in foreign interest rates and currency exchange rates. These fluctuations may impact the value of our cash receipts and payments in terms of our functional currency, the U.S. dollar. We use foreign currency forward contracts to protect the value or fix the amount of certain investments or cash flows in terms of the U.S. dollar. Designated Hedges of Foreign Currency Risk The following table details our outstanding foreign exchange derivatives that were designated as net investment hedges of foreign currency risk (notional amount in thousands): September 30, 2021 December 31, 2020 Foreign Currency Derivatives Number of Notional Amount Foreign Currency Derivatives Number of Instruments Notional Amount Buy USD / Sell SEK Forward 1 kr 999,500 Buy USD / Sell EUR Forward 8 € 754,722 Buy USD / Sell EUR Forward 6 € 817,642 Buy USD / Sell GBP Forward 4 € 372,487 Buy USD / Sell GBP Forward 1 £ 542,551 Buy USD / Sell AUD Forward 1 A$ 92,800 Buy USD / Sell AUD Forward 1 A$ 89,500 Buy USD / Sell CAD Forward 1 C$ 26,200 Buy USD / Sell CAD Forward 1 C$ 21,000 Non-designated The following table details our outstanding foreign exchange derivatives that were non-designated September 30, 2021 December 31, 2020 Non-designated Number of Notional Non-designated Number of Notional Buy GBP / Sell EUR Forward 1 € 8,410 Buy EUR / Sell GBP Forward 2 £ 146,207 Buy EUR / Sell USD Forward 1 € 13,900 Buy USD / Sell EUR Forward 1 € 8,410 Buy USD / Sell EUR Forward 1 € 13,900 Financial Statement Impact of Hedges of Foreign Currency Risk The following table presents the effect of our derivative financial instruments on our consolidated statements of operations ($ in thousands): Increase (Decrease) to Net Interest Income from Foreign Exchange Contracts Three Months Three Months Nine Months Nine Months Foreign Exchange Contracts Location of Income Ended Ended Ended Ended in Hedging Relationships (Expense) Recognized September 30, 2021 September 30, 2020 September 30, 2021 September 30, 2020 Designated Hedges Interest Income (1) $ 1,542 $ 1,794 $ 5,294 $ 2,303 Non-Designated Interest Income (1) 34 (227 ) (340 ) (222 ) Non-Designated Interest Expense (2) (8 ) 669 (7,139 ) (846 ) Total $ 1,568 $ 2,236 $ (2,185 ) $ 1,235 (1) Represents the forward points earned on our foreign currency forward contracts, which reflect the interest rate differentials between the applicable base rate for our foreign currency investments and USD LIBOR. These forward contracts effectively convert the rate exposure to USD LIBOR, resulting in additional interest income earned in U.S. dollar terms. (2) Represents the spot rate movement in our non-designated marked-to-market Valuation and Other Comprehensive Income The following table summarizes the fair value of our derivative financial instruments ($ in thousands): Fair Value of Derivatives in an Asset Position (1) Fair Value of Derivatives in a Liability Position (2) September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Derivatives designated as hedging instruments: Foreign exchange contracts $ 35,460 $ 521 $ — $ 55,758 Interest rate derivatives — 1 — — Total $ 35,460 $ 522 $ — $ 55,758 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 398 $ — $ 355 $ 3,157 Interest rate derivatives — — — — Total $ 398 $ — $ 355 $ 3,157 Total Derivatives $ 35,858 $ 522 $ 355 $ 58,915 (1) Included in other assets in our consolidated balance sheets. (2) Included in other liabilities in our consolidated balance sheets. The following table presents the effect of our derivative financial instruments on our consolidated statements of operations ($ in thousands): Amount of Gain Recognized in OCI on Derivatives Location of Gain (Loss) Amount of Loss Reclassified from Accumulated OCI into Income Three Months Nine Months Reclassified from Accumulated Three Months Nine Months Derivatives in Ended Ended Ended Ended Hedging Relationships September 30, 2021 September 30, 2021 OCI into Income September 30, 2021 September 30, 2021 Net Investment Hedges Foreign exchange contracts (1) $ 46,078 $ 65,052 Interest Expense $ — $ — Cash Flow Hedges Interest rate derivatives — — Interest Expense (2) (5 ) (7 ) Total $ 46,078 $ 65,052 $ (5 ) $ (7 ) (1) During the three and nine months ended September 30, 2021, we received net cash settlements of $18.3 million and paid net cash settlements of $31.0 million, respectively, on our foreign currency forward contracts. Those amounts are included as a component of accumulated other comprehensive income (loss) on our consolidated balance sheets. (2) During the three months ended September 30, 2021, we recorded total interest and related expenses of $82.7 million, which included interest expense of $5,000 related to our cash flow hedges. During the nine months ended September 30, 2021, we recorded total interest and related expenses of $243.4 million, which included interest expense of $7,000. Credit-Risk Related Contingent Features We have entered into agreements with certain of our derivative counterparties that contain provisions where if we were to default on any of our indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, we may also be declared in default on our derivative obligations. In addition, certain of our agreements with our derivative counterparties require that we post collateral to secure net liability positions. As of September 30, 2021, we were in a net asset position with both of our derivative counterparties and did not have any collateral posted under these derivative contracts. As of December 31, 2020, we were in a net liability position with each such derivative counterparty and posted collateral of $51.1 million under these derivative contracts.

Equity

Equity	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Equity	11. EQUITY Stock and Stock Equivalents Authorized Capital As of September 30, 2021, we had the authority to issue up to 500,000,000 shares of stock, consisting of 400,000,000 shares of class A common stock and 100,000,000 shares of preferred stock. Subject to applicable NYSE listing requirements, our board of directors is authorized to cause us to issue additional shares of authorized stock without stockholder approval. In addition, to the extent not issued, currently authorized stock may be reclassified between class A common stock and preferred stock. We did not have any shares of preferred stock issued and outstanding as of September 30, 2021 and December 31, 2020. Class A Common Stock and Deferred Stock Units Holders of shares of our class A common stock are entitled to vote on all matters submitted to a vote of stockholders and are entitled to receive such dividends as may be authorized by our board of directors and declared by us, in all cases subject to the rights of the holders of shares of outstanding preferred stock, if any. The following table details our issuances of class A common stock during the nine months ended September 30, 2021 ($ in thousands, except share and per share data): Class A Common Stock Offerings September 2021 Shares issued 10,000,000 Gross / net issue price per share (1) $31.45 / $31.24 Net proceeds (2) $311,955 (1) Represents the gross price per share issued, as well as the net proceeds per share after underwriting or sales discounts and commissions. (2) Net proceeds represents proceeds received from the underwriters less applicable transaction costs. We also issue restricted class A common stock under our stock-based incentive plans. Refer to Note 14 for additional discussion of these long-term incentive plans. In addition to our class A common stock, we also issue deferred stock units to certain members of our board of directors in lieu of cash compensation for services rendered. These deferred stock units are non-voting, The following table details the movement in our outstanding shares of class A common stock, including restricted class A common stock and deferred stock units: Nine Months Ended September 30, Common Stock Outstanding (1) 2021 2020 Beginning balance 147,086,722 135,263,728 Issuance of class A common stock (2) 10,001,429 10,842,295 Issuance of restricted class A common stock, net (3) 234,229 351,333 Issuance of deferred stock units 50,009 33,790 Ending balance 157,372,389 146,491,146 (1) Includes 356,700 and 293,856 deferred stock units held by members of our board of directors as of September 30, 2021 and 2020, respectively. (2) Includes 1,429 and 1,599 shares issued under our dividend reinvestment program during the nine months ended September 30, 2021 and 2020, respectively. (3) The amounts are net of 29,580 and 249 shares of restricted class A common stock forfeited under our stock-based incentive plans during the nine months ended September 30, 2021 and 2020, respectively. See Note 14 for further discussion of our stock-based incentive plans. Dividend Reinvestment and Direct Stock Purchase Plan On March 25, 2014, we adopted a dividend reinvestment and direct stock purchase plan, under which we registered and reserved for issuance, in the aggregate, 10,000,000 shares of class A common stock. Under the dividend reinvestment component of this plan, our class A common stockholders can designate all or a portion of their cash dividends to be reinvested in additional shares of class A common stock. The direct stock purchase component allows stockholders and new investors, subject to our approval, to purchase shares of class A common stock directly from us. During the three and nine months ended September 30, 2021, we issued 480 shares and 1,429 shares, respectively, of class A common stock under the dividend reinvestment component of the plan compared to 628 shares and 1,599 shares, respectively, for the same periods in 2020. As of September 30, 2021, a total of 9,990,545 shares of class A common stock remained available for issuance under the dividend reinvestment and direct stock purchase plan. At the Market Stock Offering Program On November 14, 2018, we entered into six equity distribution agreements, or ATM Agreements, pursuant to which we may sell, from time to time, up to an aggregate sales price of $500.0 million of our class A common stock. On July 26, 2019, we amended our existing ATM Agreements and entered into one additional ATM Agreement. Sales of class A common stock made pursuant to our ATM Agreements may be made in negotiated transactions or transactions that are deemed to be “at the market” offerings as defined in Rule 415 under the Securities Act of 1933, as amended. Actual sales depend on a variety of factors including market conditions, the trading price of our class A common stock, our capital needs, and our determination of the appropriate sources of funding to meet such needs. During the nine months ended September 30, 2021 and 2020, we did not sell any shares of our class A common stock under ATM Agreements. As of September 30, 2021, sales of our class A common stock with an aggregate sales price of $363.8 million remained available for issuance under our ATM Agreements. Dividends We generally intend to distribute substantially all of our taxable income, which does not necessarily equal net income as calculated in accordance with GAAP, to our stockholders each year to comply with the REIT provisions of the Internal Revenue Code of 1986, as amended, or the Internal Revenue Code. Our On September 15, 2021, we declared a dividend of $0.62 per share, or $97.3 million in aggregate, that was paid on October 15, 2021, to stockholders of record as of September 30, 2021. The following table details our dividend activity ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Dividends declared per share of common stock $ 0.62 $ 0.62 $ 1.86 $ 1.86 Class A common stock dividends declared $ 97,350 $ 90,642 $ 279,659 $ 265,205 Deferred stock unit dividends declared 202 174 591 502 Total dividends declared $ 97,552 $ 90,816 $ 280,250 $ 265,707 Earnings Per Share We calculate our basic and diluted earnings per share using the two-class The following table sets forth the calculation of basic and diluted net income (loss) per share of class A common stock based on the weighted-average of both restricted and unrestricted class A common stock outstanding ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net income (1) $ 83,757 $ 89,860 $ 295,254 $ 54,054 Weighted-average shares outstanding, basic and diluted 149,214,819 146,484,651 147,971,737 140,157,620 Per share amount, basic and diluted $ 0.56 $ 0.61 $ 2.00 $ 0.39 (1) Represents net income attributable to Blackstone Mortgage Trust. Other Balance Sheet Items Accumulated Other Comprehensive Income As of September 30, 2021, total accumulated other comprehensive income was $9.9 million, primarily including $69.9 million of net realized and unrealized gains related to changes in the fair value of derivative instruments, offset by $60.0 million of cumulative unrealized currency translation adjustments on assets and liabilities denominated in foreign currencies. As of December 31, 2020, total accumulated other comprehensive income was $11.2 million, primarily representing (i) $6.4 million of cumulative unrealized currency translation adjustments on assets and liabilities denominated in foreign currencies, and (ii) $4.8 million of net realized and unrealized gains related to changes in the fair value of derivative instruments. Non-Controlling The non-controlling non-controlling non-controlling non-controlling

Other Expenses

Other Expenses	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
Other Expenses	12. OTHER EXPENSES Our other expenses consist of the management and incentive fees we pay to our Manager and our general and administrative expenses. Management and Incentive Fees Pursuant to a management agreement between our Manager and us, or our Management Agreement, our Manager earns a base management fee in an amount equal to 1.50% per annum multiplied by our outstanding equity balance, as defined in the Management Agreement. In addition, our Manager is entitled to an incentive fee in an amount equal to the product of (i) 20% and (ii) the excess of (a) our Core Earnings (as defined in our Management Agreement) for the previous 12-month (i) non-cash non-cash During the three and nine months ended September 30, 2021, we incurred $15.8 million and $46.9 million, respectively, of management fees payable to our Manager, compared to $15.6 million and $44.8 million during the same period in 2020. In addition, during the three and nine months ended September 30, 2021, we incurred $3.6 million and $13.2 million, respectively, of incentive fees payable to our Manager, compared to $3.4 million and $13.9 million during the same period in 2020. During the nine months ended September 30, 2021, we paid $59.9 million of aggregate management and incentive fees in cash. During the nine months ended September 30, 2020, we issued 840,696 shares of class A common stock to our Manager in satisfaction of our aggregate $19.3 million of management and incentive fees accrued in the first quarter of 2020, and paid the remaining $40.7 million in cash. As of September 30, 2021 and December 31, 2020 we had accrued management and incentive fees payable to our Manager of $19.3 million and $19.2 million, respectively, which are included in Other Liabilities on our consolidated balance sheets. General and Administrative Expenses General and administrative expenses consisted of the following ($ in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Professional services (1) $ 1,969 $ 1,715 $ 5,831 $ 5,130 Operating and other costs (1) 792 878 2,093 3,212 Subtotal 2,761 2,593 7,924 8,342 Non-cash Restricted class A common stock earned 7,907 8,524 23,762 25,603 Director stock-based compensation 173 125 422 375 Subtotal 8,080 8,649 24,184 25,978 Total general and administrative expenses $ 10,841 $ 11,242 $ 32,108 $ 34,320 (1) During the three and nine months ended September 30, 2021, we recognized an aggregate $110,000 and $543,000, respectively, of expenses related to our Multifamily Joint Venture. During the three and nine months ended September 30, 2020, we recognized an aggregate $293,000 and $869,000, respectively, of expenses related to our Multifamily Joint Venture.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	13. INCOME TAXES We have elected to be taxed as a REIT under the Internal Revenue Code for U.S. federal income tax purposes. We generally must distribute annually at least 90% of our net taxable income, subject to certain adjustments and excluding any net capital gain, in order for U.S. federal income tax not to apply to our earnings that we distribute. To the extent that we satisfy this distribution requirement, but distribute less than 100% of our net taxable income, we will be subject to U.S. federal income tax on our undistributed taxable income. In addition, we will be subject to a 4% nondeductible excise tax if the actual amount that we pay out to our stockholders in a calendar year is less than a minimum amount specified under U.S. federal tax laws. Our qualification as a REIT also depends on our ability to meet various other requirements imposed by the Internal Revenue Code, which relate to organizational structure, diversity of stock ownership, and certain restrictions with regard to the nature of our assets and the sources of our income. Even if we qualify as a REIT, we may be subject to certain U.S. federal income and excise taxes and state and local taxes on our income and assets. If we fail to maintain our qualification as a REIT for any taxable year, we may be subject to material penalties as well as federal, state, and local income tax on our taxable income at regular corporate rates and we would not be able to qualify as a REIT for the subsequent four full taxable years. As of September 30, 2021 and December 31, 2020, we were in compliance with all REIT requirements. Securitization transactions could result in the creation of taxable mortgage pools for federal income tax purposes. As a REIT, so long as we own 100% of the equity interests in a taxable mortgage pool, we generally would not be adversely affected by the characterization of the securitization as a taxable mortgage pool. Certain categories of stockholders, however, such as foreign stockholders eligible for treaty or other benefits, stockholders with net operating losses, and certain tax-exempt During the three and nine months ended September 30, 2021, we recorded a current income tax provision of $70,000 and $346,000, respectively, primarily related to activities of our taxable REIT subsidiaries and various state and local taxes. During the three and nine months ended September 30, 2020, we recorded a current income tax provision of $20,000 and $192,000, respectively. We did not have any deferred tax assets or liabilities as of September 30, 2021 or December 31, 2020. We have net operating losses, or NOLs, generated by our predecessor business that may be carried forward and utilized in current or future periods. As a result of our issuance of 25,875,000 shares of class A common stock in May 2013, the availability of our NOLs is generally limited to $2.0 million per annum by change of control provisions promulgated by the Internal Revenue Service with respect to the ownership of Blackstone Mortgage Trust. As of December 31, 2020, we had estimated NOLs of $159.0 million that will expire in 2029 As of September 30, 2021, tax years 2017 through 2020

Stock-Based Incentive Plans

Stock-Based Incentive Plans	9 Months Ended
	Sep. 30, 2021
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Incentive Plans	14. STOCK-BASED INCENTIVE PLANS We are externally managed by our Manager and do not currently have any employees. However, as of September 30, 2021, our Manager, certain individuals employed by an affiliate of our Manager, and certain members of our board of directors were compensated, in part, through our issuance of stock-based instruments. We had stock-based incentive awards outstanding under nine benefit plans as of September 30, 2021. Seven of such benefit plans have expired and no new awards may be issued under them. Under our two current benefit plans, a maximum of 5,000,000 shares of our class A common stock may be issued to our Manager, our directors and officers, and certain employees of affiliates of our Manager. As of September 30, 2021, there were 1,978,860 shares available under our current benefit plans. The following table details the movement in our outstanding shares of restricted class A common stock and the weighted-average grant date fair value per share: Restricted Class A Weighted-Average Balance as of December 31, 2020 1,627,890 $ 33.14 Granted 263,809 26.16 Vested (718,799 ) 33.08 Forfeited (29,580 ) 31.52 Balance as of September 30, 2021 1,143,320 $ 31.60 These shares generally vest in installments over a three-year period, pursuant to the terms of the respective award agreements and the terms of our current benefit plans. The 1,143,320 shares of restricted class A common stock outstanding as of September 30, 2021 will vest as follows: 239,145 shares will vest in 2021; 626,395 shares will vest in 2022; and 277,780 shares will vest in 2023. As of September 30, 2021, total unrecognized compensation cost relating to unvested share-based compensation arrangements was $33.6 million based on the grant date fair value of shares granted. This cost is expected to be recognized over a weighted-average period of 1.0 years from September 30, 2021.

Fair Values

Fair Values	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Values	15. FAIR VALUES Assets and Liabilities Measured at Fair Value The following table summarizes our assets and liabilities measured at fair value on a recurring basis ($ in thousands): September 30, 2021 December 31, 2020 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Derivatives $ — $ 35,858 $ — $ 35,858 $ — $ 522 $ — $ 522 Liabilities Derivatives $ — $ 355 $ — $ 355 $ — $ 58,915 $ — $ 58,915 Refer to Note 2 for further discussion regarding fair value measurement. Fair Value of Financial Instruments As discussed in Note 2, GAAP requires disclosure of fair value information about financial instruments, whether or not recognized at fair value in the statement of financial position, for which it is practicable to estimate that value. The following table details the book value, face amount, and fair value of the financial instruments described in Note 2 ($ in thousands): September 30, 2021 December 31, 2020 Book Face Fair Book Face Fair Value Amount Value Value Amount Value Financial assets Cash and cash equivalents $ 211,180 $ 211,180 $ 211,180 $ 289,970 $ 289,970 $ 289,970 Loans receivable, net 20,276,078 20,522,560 20,358,824 16,399,166 16,652,824 16,447,192 Debt securities held-to-maturity (1) 77,636 79,200 78,633 75,722 79,200 70,127 Financial liabilities Secured debt, net 11,170,330 11,188,855 11,188,855 7,880,536 7,896,863 7,896,863 Securitized debt obligations, net 2,836,049 2,855,625 2,855,589 2,922,499 2,940,638 2,923,489 Asset-specific debt, net 320,895 328,068 328,068 391,269 399,699 399,699 Term loans, net 1,329,637 1,352,706 1,343,771 1,041,704 1,062,766 1,053,060 Convertible notes, net 618,985 622,500 633,845 616,389 622,500 621,568 (1) Included in other assets on our consolidated balance sheets. Estimates of fair value for cash and cash equivalents and convertible notes are measured using observable, quoted market prices, or Level 1 inputs. Estimates o f

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	16. VARIABLE INTEREST ENTITIES Consolidated Variable Interest Entities We have financed a portion of our loans through the CLOs and the 2017 Single Asset Securitization, all of which are VIEs. During the nine months ended September 30, 2021, the 2017 Single Asset Securitization was liquidated upon full repayment of its collateral assets and all senior securities outstanding. Previously, the 2017 Single Asset Securitization was consolidated by us. We are the primary beneficiary of, and therefore consolidate, the CLOs on our balance sheet as we (i) control the relevant interests of the CLOs that give us power to direct the activities that most significantly affect the CLOs, and (ii) have the right to receive benefits and obligation to absorb losses of the CLOs through the subordinate interests we own. The following table details the assets and liabilities of our consolidated CLOs and 2017 Single Asset Securitization VIEs ($ in thousands): September 30, 2021 December 31, 2020 Assets: Loans receivable $ 3,475,000 $ 3,520,130 Current expected credit loss reserve (4,044 ) (13,454 ) Loans receivable, net 3,470,956 3,506,676 Other assets 32,406 81,274 Total assets $ 3,503,362 $ 3,587,950 Liabilities: Securitized debt obligations, net $ 2,836,049 $ 2,922,499 Other liabilities 1,631 2,104 Total liabilities $ 2,837,680 $ 2,924,603 Assets held by these VIEs are restricted and can be used only to settle obligations of the VIEs, including the subordinate interests owned by us. The liabilities of these VIEs are non-recourse Non-Consolidated In the third quarter of 2018, we contributed a $517.5 million loan to the $1.0 billion 2018 Single Asset Securitization, which is a VIE, and invested in the related $99.0 million subordinate position. We are not the primary beneficiary of the VIE because we do not have the power to direct the activities that most significantly affect the VIE’s economic performance and, therefore, do not consolidate the 2018 Single Asset Securitization on our balance sheet. We have classified the subordinate position we own as a held-to-maturity We are not obligated to provide, have not provided, and do not intend to provide financial support to these consolidated and non-consolidated

Transactions With Related Parti

Transactions With Related Parties	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Transactions With Related Parties	17. TRANSACTIONS WITH RELATED PARTIES We are managed by our Manager pursuant to the Management Agreement, the current term of which expires on December 19, 2021, and will be automatically renewed for a one-year As of September 30, 2021 and December 31, 2020, our consolidated balance sheets included $19.3 million and $19.2 million of accrued management and incentive fees payable to our Manager, respectively. During the three and nine months ended September 30, 2021, we paid aggregate management and incentive fees of $21.5 million and $59.9 million, respectively, to our Manager, compared to $20.5 million and $59.9 million during the same periods of 2020. During the nine months ended September 30, 2020, we issued 840,696 shares of class A common stock to our Manager in satisfaction of our aggregate $19.3 million of management and incentive fees accrued in the first quarter of 2020. The per share price with respect to such issuance was calculated based on the volume-weighted average price on the NYSE of our class A common stock over the five trading days following our April 29, 2020 first quarter 2020 earnings conference call. In addition, during the three and nine months ended September 30, 2021, we reimbursed our Manager for expenses incurred on our behalf of $141,000 and $325,000, respectively, compared to $416,000 and $839,000 during the same periods of 2020. As of September 30, 2021, our Manager held 578,914 shares of unvested restricted class A common stock, which had an aggregate grant date fair value of $18.5 million, and vest in installments over three years from the date of issuance. During the three and nine months ended September 30, 2021, we recorded non-cash An affiliate of our Manager is the special servicer of the CLOs. This affiliate did not earn any special servicing fees related to the CLOs during the nine months ended September 30, 2021 or 2020. During the nine month periods ended September 30, 2021 and 2020, we originated three loans and two loans, respectively, whereby the respective borrowers engaged an affiliate of our Manager to act as title insurance agent in connection with these transactions. We did not incur any expenses or receive any revenues as a result of these transactions. During the three and nine months ended September 30, 2021, we incurred $100,000 and $291,000, respectively, of expenses for various administrative, compliance, and capital market data services to third-party service providers that are affiliates of our Manager, compared to $98,000 and $369,000 during the same periods of 2020. In the third quarter of 2021, we originated $246.6 million of a total $503.3 million senior loan to an unaffiliated third-party, which was part of a total financing that included a mezzanine loan originated by a Blackstone-advised investment vehicle. We will forgo all non-economic In the third quarter of 2021, we acquired an aggregate £186.0 million of a total £379.6 million senior loan to a borrower that is majority owned by a Blackstone-advised investment vehicle. We will forgo all non-economic In the third quarter of 2021, we co-originated co-originated co-originated In the third and fourth quarter of 2019, we acquired an aggregate €250.0 million of a total €1.6 billion senior loan to a borrower that is partially owned by a Blackstone-advised investment vehicle. We will forgo all non-economic In the second quarter of 2021, we acquired an aggregate €50.0 million of a total €491.0 million senior loan to a borrower that is majority owned by a Blackstone-advised investment vehicle. We will forgo all non-economic In the second quarter of 2021 and 2020, certain Blackstone-advised investment vehicles acquired an aggregate $20.0 million participation, or 5%, of the initial aggregate B-2 In the first quarter of 2021 and second quarter and fourth quarter of 2019, certain Blackstone-advised investment vehicles acquired an aggregate $65.5 million participation, or 7%, of the initial aggregate B-1 In the first quarter of 2021, we acquired an SEK 5.0 billion interest in a total SEK 10.2 billion senior loan to a borrower that is wholly owned by a Blackstone-advised investment vehicle. We will forgo all non-economic In the first quarter of 2020, we acquired a $140.0 million interest in a total $421.5 million senior loan to a borrower that is partially owned by a Blackstone-advised investment vehicle. We will forgo all non-economic

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	18. COMMITMENTS AND CONTINGENCIES Impact of COVID-19 As further discussed in Note 2, the full extent of the impact of COVID-19 COVID-19, COVID-19. Unfunded Commitments Under Loans Receivable As of September 30, 2021, we had aggregate unfunded loan commitments of $4.2 billion across 108 loans receivable, and billion of committed or identified financings for those commitments, resulting in net unfunded commitments of billion. The unfunded loan commitments comprise funding for capital expenditures and construction, leasing costs, and interest and carry costs, and their funding will vary depending on the progress of capital projects, leasing, and cash flows at the properties securing our loans. Therefore, the exact timing and amounts of such future loan fundings are uncertain and will depend on the current and future performance of the underlying collateral assets. We expect to fund our loan commitments over the remaining term of the related loans, which have a weighted-average future funding period of Principal Debt Repayments Our contractual principal debt repayments as of September 30, 2021 were as follows ($ in thousands): Secured Asset-Specific Term Convertible Year Debt (1) Debt (1) Loans (2) Notes (3) Total (4) 2021 (remainder of the year) $ 130,668 $ — $ 3,436 $ — $ 134,104 2022 228,030 — 13,738 402,500 644,268 2023 1,834,836 149,896 13,738 220,000 2,218,470 2024 3,937,001 — 13,738 — 3,950,739 2025 1,231,023 178,172 13,738 — 1,422,933 2026 3,725,205 — 1,294,318 — 5,019,523 Thereafter 102,092 — — — 102,092 Total obligation $ 11,188,855 $ 328,068 $ 1,352,706 $ 622,500 $ 13,492,129 (1) The allocation of repayments under our secured debt and asset-specific debt is based on the earlier of (i) the maturity date of each agreement, or (ii) the maximum maturity date of the collateral loans, assuming all extension options are exercised by the borrower. (2) The Term Loans are partially amortizing, with an amount equal to 1.0% per annum of the principal balance due in quarterly installments. Refer to Note 8 for further details on our term loans. (3) Reflects the outstanding principal balance of Convertible Notes, excluding any potential conversion premium. Refer to Note 9 for further details on our Convertible Notes. (4) Total does not include $2.9 billion of consolidated securitized debt obligations, $997.6 million of non-consolidated non-consolidated Board of Directors’ Compensation As of September 30, 2021, of the nine members of our board of directors, our six independent directors are entitled to annual compensation of $210,000 each, of which $95,000 will be paid in the form of cash and $115,000 will be paid in the form of deferred stock units or, beginning in 2022, at their election, shares of restricted common stock. The other three board members, including our chairman and our chief executive officer, are not compensated by us for their service as directors. In addition, (i) the chairs of our audit, compensation, and corporate governance committees receive additional annual cash compensation of $20,000, $15,000, and $10,000, respectively and (ii) the members of our audit and investment risk management committees receive additional annual cash compensation of $10,000 and $7,500, respectively. Litigation From time to time, we may be involved in various claims and legal actions arising in the ordinary course of business. As of September 30, 2021, we were not involved in any material legal proceedings.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	19. SUBSEQUENT EVENTS On October 5, 2021, we issued $400.0 million aggregate principal amount of 3.75% senior secured notes due 2027,

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include, on a consolidated basis, our accounts, the accounts of our wholly-owned subsidiaries, majority-owned subsidiaries, and variable interest entities, or VIEs, of which we are the primary beneficiary. All intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications have been made in the presentation of the prior period statements of changes in equity, statements of cash flows, and loans receivable in Note 3 to conform to the current period presentation.
Principles of Consolidation	Principles of Consolidation We consolidate all entities that we control through either majority ownership or voting rights. In addition, we consolidate all VIEs of which we are considered the primary beneficiary. VIEs are defined as entities in which equity investors (i) do not have the characteristics of a controlling financial interest and/or (ii) do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties. The entity that consolidates a VIE is known as its primary beneficiary and is generally the entity with (i) the power to direct the activities that most significantly affect the VIE’s economic performance and (ii) the right to receive benefits from the VIE or the obligation to absorb losses of the VIE that could be significant to the VIE. In the third quarter of 2018, we contributed a loan to a single asset securitization vehicle, or the 2018 Single Asset Securitization, which is a VIE, and invested in the related subordinate position. We are not the primary beneficiary of the VIE because we do not have the power to direct the activities that most significantly affect the VIE’s economic performance and, therefore, do not consolidate the 2018 Single Asset Securitization on our balance sheet. We have classified the subordinate position we own as a held-to-maturity In April 2017, we entered into a joint venture, or our Multifamily Joint Venture, with Walker & Dunlop Inc. to originate, hold, and finance multifamily bridge loans. Pursuant to the terms of the agreements governing the joint venture, Walker & Dunlop contributed 15% of the venture’s equity capital and we contributed 85%. We consolidate the Multifamily Joint Venture as we have a controlling financial interest. The non-controlling non-controlling
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The novel coronavirus, or COVID-19 COVID-19 COVID-19.
Revenue Recognition	Revenue Recognition Interest income from our loans receivable portfolio and debt securities is recognized over the life of each investment using the effective interest method and is recorded on the accrual basis. Recognition of fees, premiums, and discounts associated with these investments is deferred and recorded over the term of the loan or debt security as an adjustment to yield. Income accrual is generally suspended for loans at the earlier of the date at which payments become 90 days past due or when, in the opinion of our Manager, recovery of income and principal becomes doubtful. Interest received is then recorded as a reduction in the outstanding principal balance until accrual is resumed when the loan becomes contractually current and performance is demonstrated to be resumed. In addition, for loans we originate, the related origination expenses are deferred and recognized as a component of interest income, however expenses related to loans we acquire are included in general and administrative expenses as incurred.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents represent cash held in banks and liquid investments with original maturities of three months or less. We may have bank balances in excess of federally insured amounts; however, we deposit our cash and cash equivalents with high credit-quality institutions to minimize credit risk exposure. We have not experienced, and do not expect, any losses on our cash or cash equivalents. Restricted cash represents cash collateral held within our 2021 FL4 collateralized loan obligation and is included in Other Assets on our consolidated balance sheets. See Note 6 for further discussion of the 2021 FL4 collateralized loan obligation. The following table provides a reconciliation of cash, cash equivalents, and restricted cash on our consolidated balance sheets to the total amount shown on our consolidated statements of cash flows ($ in thousands): September 30, 2021 September 30, 2020 Cash and cash equivalents $ 211,180 $ 427,028 2021 FL4 CLO restricted cash 25,000 — Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows $ 236,180 $ 427,028 Through our subsidiaries, we have oversight of certain servicing accounts held with third-party servicers, or Servicing Accounts, which relate to borrower escrows and other cash balances aggregating $426.6 million and $384.6 million as of September 30, 2021 and December 31, 2020, respectively. This cash is maintained in segregated bank accounts, and these amounts are not included in the assets and liabilities presented in our consolidated balance sheets. Cash in these Servicing Accounts will be transferred by the respective third-party servicer to the borrower or us under the terms of the applicable loan agreement upon occurrence of certain future events. We do not generate any revenue or incur any expenses as a result of these Servicing Accounts.
Loans Receivable	Loans Receivable We originate and purchase commercial real estate debt and related instruments generally to be held as long-term investments at amortized cost.
Debt Securities Held-to-Maturity	Debt Securities Held-to-Maturity We classify our debt securities as held-to-maturity,
Current Expected Credit Losses Reserve	Current Expected Credit Losses Reserve The current expected credit loss, or CECL, reserve required under Accounting Standard Update, or ASU, 2016-13 2016-13, 2016-13 2016-13 We estimate our CECL reserve primarily using the Weighted Average Remaining Maturity, or WARM, method which has been identified as an acceptable loss-rate method for estimating CECL reserves in the Financial Accounting Standards Board Staff Q&A Topic 326, No. 1. The WARM method requires us to reference historic loan loss data across a comparable data set and apply such loss rate to each of our loans over their expected remaining term, taking into consideration expected economic conditions over the relevant timeframe. We apply the WARM method for the majority of our loan portfolio, which loans share similar risk characteristics. In certain instances, for loans with unique risk characteristics, we may instead use a probability-weighted model that considers the likelihood of default and expected loss given default for each such individual loan. Application of the WARM method to estimate a CECL reserve requires judgment, including (i) the appropriate historical loan loss reference data, (ii) the expected timing and amount of future loan fundings and repayments, and (iii) the current credit quality of our portfolio and our expectations of performance, and (iv) market conditions over the relevant time period. To estimate the historic loan losses relevant to our portfolio, we have augmented our historical loan performance, which includes zero realized loan losses since the launch of our senior loan origination business in 2013, with market loan loss data licensed from Trepp LLC. This database includes commercial mortgage-backed securities, or CMBS, issued since January 1, 1999 through August 31, 2021. Within this database, we focused our historical loss reference calculations on the most relevant subset of available CMBS data, which we determined based on loan metrics that are most comparable to our loan portfolio including asset type, geography, and origination loan-to-value, Our loans typically include commitments to fund incremental proceeds to our borrowers over the life of the loan, which future funding commitments are also subject to the CECL model. The CECL reserve related to future loan fundings is recorded as a component of Other Liabilities on our consolidated balance sheets. This CECL reserve is estimated using the same process outlined above for our outstanding loan balances, and changes in this component of the CECL reserve will similarly impact our consolidated net income. For both the funded and unfunded portions of our loans, we consider our internal risk rating of each loan as the primary credit quality indicator underlying our assessment. The CECL reserve is measured on a collective basis wherever similar risk characteristics exist within a pool of similar assets. We have identified the following pools and measure the reserve for credit losses using the following methods: • U.S. Loans • Non-U.S. • Unique Loans • Impaired Loans non-recoverability We adopted ASU 2016-13 Impact of ASU 2016-13 Adoption Assets: Loans U.S. Loans $ 8,955 Non-U.S. 3,631 Unique Loans 1,356 CECL reserve on loans $ 13,942 CECL reserve on held-to-maturity 445 Liabilities: CECL reserve on unfunded loan commitments 3,263 Total impact of ASU 2016-13 $ 17,650 Contractual Term and Unfunded Loan Commitments Expected credit losses are estimated over the contractual term of each loan, adjusted for expected prepayments. As part of our quarterly review of our loan portfolio, we assess the expected repayment date of each loan, which is used to determine the contractual term for purposes of computing our CECL reserve. Additionally, the expected credit losses over the contractual period of our loans are subject to the obligation to extend credit through our unfunded loan commitments. The CECL reserve for unfunded loan commitments is adjusted quarterly, as we consider the expected timing of future funding obligations over the estimated life of the loan. The considerations in estimating our CECL reserve for unfunded loan commitments are similar to those used for the related outstanding loan receivables. Credit Quality Indicator Our risk rating is our primary credit quality indicator in assessing our current expected credit loss reserve. Our Manager performs a quarterly risk review of our portfolio of loans, and assigns each loan a risk rating based on a variety of factors, including, without limitation, LTV, debt yield, property type, geographic and local market dynamics, physical condition, cash flow volatility, leasing and tenant profile, loan structure and exit plan, and project sponsorship. Based on a 5-point 1 - Very Low Risk 2 - Low Risk 3 - Medium Risk 4 - High Risk/Potential for Loss: 5 - Impaired/Loss Likely: Estimation of Economic Conditions In addition to the WARM method computations and probability-weighted models described above, our CECL reserve is also adjusted to reflect our estimation of the current and future economic conditions that impact the performance of the commercial real estate assets securing our loans. These estimations include unemployment rates, interest rates, and other macroeconomic factors impacting the likelihood and magnitude of potential credit losses for our loans during their anticipated term. In addition to the CMBS data we have licensed from Trepp LLC, we have also licensed certain macroeconomic financial forecasts to inform our view of the potential future impact that broader economic conditions may have on our loan portfolio’s performance. These estimations require significant judgments about future events that, while based on the information available to us as of the balance sheet date, are ultimately indeterminate and the actual economic condition impacting our portfolio could vary significantly from the estimates we made as of September 30, 2021.
Derivative Financial Instruments	Derivative Financial Instruments We classify all derivative financial instruments as either other assets or other liabilities on our consolidated balance sheets at fair value. On the date we enter into a derivative contract, we designate each contract as (i) a hedge of a net investment in a foreign operation, or net investment hedge, (ii) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability, or cash flow hedge, (iii) a hedge of a recognized asset or liability, or fair value hedge, or (iv) a derivative instrument not to be designated as a hedging derivative, or non-designated non-designated On a quarterly basis, we also formally assess whether the derivative we designated in each hedging relationship is expected to be, and has been, highly effective in offsetting changes in the value or cash flows of the hedged items. If it is determined that a derivative is not highly effective at hedging the designated exposure, hedge accounting is discontinued and the changes in fair value of the instrument are included in net income prospectively. Effective April 1, 2020, our net investment hedges are assessed using a method based on changes in spot exchange rates. Gains and losses, representing hedge components excluded from the assessment of effectiveness, are recognized in interest income on our consolidated statements of operations over the contractual term of our net investment hedges on a systematic and rational basis, as documented at hedge inception in accordance with our accounting policy election. All other changes in the fair value of our derivative instruments that qualify as hedges are reported as a component of accumulated other comprehensive income (loss) on our consolidated financial statements. Deferred gains and losses are reclassified out of accumulated other comprehensive income (loss) and into net income in the same period or periods during which the hedged transaction affects earnings, and are presented in the same line item as the earnings effect of the hedged item. For cash flow hedges, this is typically when the periodic swap settlements are made, while for net investment hedges, this occurs when the hedged item is sold or substantially liquidated. To the extent a derivative does not qualify for hedge accounting and is deemed a non-designated
Secured Debt and Asset-Specific Debt	Secured Debt and Asset-Specific Debt We record investments financed with secured debt or asset-specific debt as separate assets and the related borrowings under any secured debt or asset-specific debt are recorded as separate liabilities on our consolidated balance sheets. Interest income earned on the investments and interest expense incurred on the secured debt or asset-specific debt are reported separately on our consolidated statements of operations.
Senior Loan Participations	Senior Loan Participations In certain instances, we finance our loans through the non-recourse syndication the non-consolidated senior
Term Loans	Term Loans We record our term loans as liabilities on our consolidated balance sheets. Where applicable, any issue discount or transaction expenses are deferred and amortized through the maturity date of the term loans as additional non-cash
Convertible Notes	Convertible Notes The “Debt with Conversion and Other Options” Topic of the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, requires the liability and equity components of convertible debt instruments that may be settled in cash upon conversion, including partial cash settlement, to be separately accounted for in a manner that reflects the issuer’s nonconvertible debt borrowing rate. The initial proceeds from the sale of convertible notes are allocated between a liability component and an equity component in a manner that reflects interest expense at the rate of similar nonconvertible debt that could have been issued at such time. The equity component represents the excess initial proceeds received over the fair value of the liability component of the notes as of the date of issuance. We measured the estimated fair value of the debt component of our convertible notes as of the respective issuance dates based on our nonconvertible debt borrowing rate. The equity component of each series of our convertible notes is reflected within additional paid-in non-cash non-cash
Deferred Financing Costs	Deferred Financing Costs The deferred financing costs that are included as a reduction in the net book value of the related liability on our consolidated balance sheets include issuance and other costs related to our debt obligations. These costs are amortized as interest expense using the effective interest method over the life of the related obligations.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The “Fair Value Measurements and Disclosures” Topic of the FASB, or ASC 820, defines fair value, establishes a framework for measuring fair value, and requires certain disclosures about fair value measurements under GAAP. Specifically, this guidance defines fair value based on exit price, or the price that would be received upon the sale of an asset or the transfer of a liability in an orderly transaction between market participants at the measurement date. ASC 820 also establishes a fair value hierarchy that prioritizes and ranks the level of market price observability used in measuring financial instruments. Market price observability is affected by a number of factors, including the type of financial instrument, the characteristics specific to the financial instrument, and the state of the marketplace, including the existence and transparency of transactions between market participants. Financial instruments with readily available quoted prices in active markets generally will have a higher degree of market price observability and a lesser degree of judgment used in measuring fair value. Financial instruments measured and reported at fair value are classified and disclosed based on the observability of inputs used in the determination, as follows: • Level 1: Generally includes only unadjusted quoted prices that are available in active markets for identical financial instruments as of the reporting date. • Level 2: Pricing inputs include quoted prices in active markets for similar instruments, quoted prices in less active or inactive markets for identical or similar instruments where multiple price quotes can be obtained, and other observable inputs, such as interest rates, yield curves, credit risks, and default rates. • Level 3: Pricing inputs are unobservable for the financial instruments and include situations where there is little, if any, market activity for the financial instrument. These inputs require significant judgment or estimation by management of third-parties when determining fair value and generally represent anything that does not meet the criteria of Levels 1 and 2. The estimated value of each asset reported at fair value using Level 3 inputs is determined by an internal committee composed of members of senior management of our Manager, including our Chief Executive Officer, Chief Financial Officer, and other senior officers. Certain of our other assets are reported at fair value, as of quarter-end, During the three months ended June 30, 2020, we recorded an aggregate $69.7 million CECL reserve specifically related to two of our loans receivable, which was unchanged as of September 30, 2021. These two loans have an aggregate outstanding principal balance of $338.7 million, net of cost-recovery proceeds, as of September 30, 2021. The CECL reserve was recorded based on our Manager’s estimation of the fair value of the loan’s underlying collateral as of September 30, 2021. These loans receivable are therefore measured at fair value on a nonrecurring basis using significant unobservable inputs, and are classified as Level 3 assets in the fair value hierarchy. The significant unobservable inputs used to estimate the fair value of these loans receivable include the exit capitalization rate assumption used to forecast the future sale price of the underlying real estate collateral, which ranged from 4.25% to 4.80%. We are also required by GAAP to disclose fair value information about financial instruments, which are not otherwise reported at fair value in our consolidated balance sheet, to the extent it is practicable to estimate a fair value for those instruments. These disclosure requirements exclude certain financial instruments and all non-financial The following methods and assumptions are used to estimate the fair value of each class of financial instruments, for which it is practicable to estimate that value: • Cash and cash equivalents: The carrying amount of cash and cash equivalents approximates fair value. • Loans receivable, net: The fair values of these loans were estimated by our Manager based on a discounted cash flow methodology, taking into consideration various factors including capitalization rates, discount rates, leasing, credit worthiness of major tenants, occupancy rates, availability and cost of financing, exit plan, loan sponsorship, actions of other lenders, and other factors deemed relevant by our Manager. • Debt securities held-to-maturity: • Derivative financial instruments: The fair value of our foreign currency and interest rate contracts was estimated using advice from a third-party derivative specialist, based on contractual cash flows and observable inputs comprising foreign currency rates and credit spreads. • Secured debt, net: The fair value of these instruments was estimated based on the rate at which a similar credit facility would currently be priced. • Securitized debt obligations, net: The fair value of these instruments was estimated by utilizing third-party pricing service providers. In determining the value of a particular investment, pricing service providers may use broker-dealer quotations, reported trades, or valuation estimates from their internal pricing models to determine the reported price. • Asset-specific debt, net: The fair value of these instruments was estimated based on the rate at which a similar agreement would currently be priced. • Term loans, net: The fair value of these instruments was estimated by utilizing third-party pricing service providers. In determining the value of a particular investment, pricing service providers may use broker-dealer quotations, reported trades, or valuation estimates from their internal pricing models to determine the reported price. • Convertible notes, net: Each series of the convertible notes is actively traded and their fair values were obtained using quoted market prices.
Income Taxes	Income Taxes Our financial results generally do not reflect provisions for current or deferred income taxes on our REIT taxable income. We believe that we operate in a manner that will continue to allow us to be taxed as a REIT and, as a result, we generally do not expect to pay substantial corporate level taxes other than those payable by our taxable REIT subsidiaries. If we were to fail to meet these requirements, we may be subject to federal, state, and local income tax on current and past income, and penalties. Refer to Note 13 for additional information.
Stock-Based Compensation	Stock-Based Compensation Our stock-based compensation consists of awards issued to our Manager and certain individuals employed by an affiliate of our Manager that vest over the life of the awards, as well as deferred stock units issued to certain members of our board of directors. Stock-based compensation expense is recognized for these awards in net income on a variable basis over the applicable vesting period of the awards, based on the value of our class A common stock. Refer to Note 14 for
Earnings per Share	Earnings per Share Basic earnings per share, or Basic EPS, is computed in accordance with the two-class two-class Diluted earnings per share, or Diluted EPS, is determined using the treasury stock method, and is based on the net earnings allocable to our class A common stock, including restricted class A common stock and deferred stock units, divided by the weighted-average number of shares of our class A common stock, including restricted class A common stock and deferred stock units. Refer to Note 11 for additional discussion of earnings per share.
Foreign Currency	Foreign Currency In the normal course of business, we enter into transactions not denominated in United States, or U.S., dollars. Foreign exchange gains and losses arising on such transactions are recorded as a gain or loss in our consolidated statements of operations. In addition, we consolidate entities that have a non-U.S. Non-U.S. non-U.S.
Underwriting Commissions and Offering Costs	Underwriting Commissions and Offering Costs Underwriting commissions and offering costs incurred in connection with common stock offerings are reflected as a reduction of additional paid-in
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04 2020-04. 2020-04 collectively, IBORs, to alternative reference rates. ASU 2020-04 2021-01 2021-01. 2021-01 2020-04 2020-04 2020-04 2020-04 In August 2020, the FASB issued ASU 2020-06 470-20) 815-40): 2020-06. 2020-06 2020-06 2020-06 2020-06, non-cash 2020-06 2020-06 paid-in
Reference Rate Reform	Reference Rate Reform LIBOR and certain other floating rate benchmark indices to which our floating rate loans and other loan agreements are tied, including, without limitation, the Euro Interbank Offered Rate, or EURIBOR, the Stockholm Interbank Offered Rate, or STIBOR, the Canadian Dollar Offered Rate, or CDOR, and the Australian Bank Bill Swap Reference Rate, or BBSY, or collectively, IBORs, are the subject of recent national, international and regulatory guidance and proposals for reform. On March 5, 2021, the Financial Conduct Authority of the U.K., or FCA, which has statutory powers to require panel banks to contribute to LIBOR where necessary, announced it would cease publication of certain IBORs, including one-week two-month The U.S. Federal Reserve, in conjunction with the Alternative Reference Rates Committee, a steering committee comprised of large U.S. financial institutions, has identified the Secured Overnight Financing Rate, or SOFR, a new index calculated using short-term repurchase agreements backed by Treasury securities, as its preferred alternative rate for USD LIBOR. In the U.K., the Bank of England’s working group on Sterling risk free rates set March 31, 2021 as the target date under which GBP LIBOR may no longer be used as the reference rate for new loan products with maturities after December 31, 2021. Market participants have started to transition to the Sterling Overnight Index Average, or SONIA, in line with guidance from the U.K. regulators. As of September 30, 2021, the floating benchmark rate for the financing provided on the 2020 FL3 and 2020 FL2 CLOs is the 30-day 30-day one-month ive At this time, it is not possible to predict how markets will respond to SOFR, SONIA, or other alternative reference rates as the transition away from USD LIBOR and GBP LIBOR proceeds. Despite the LIBOR transition in other markets, benchmark rate methodologies in Europe, Canada, and Australia have been reformed and rates such as EURIBOR, STIBOR, CDOR, and BBSY may persist as International Organization of Securities Commissions, or IOSCO, compliant reference rates moving forward. However, multi-rate environments may persist in these markets as regulators and working groups have suggested market participants adopt alternative reference rates. Refer to “Part I. Item 1A. Risk Factors—Risks Related to Our Lending and Investment Activities—The expected discontinuation of currently used financial reference rates and use of alternative replacement reference rates may adversely affect net interest income related to our loans and investments or otherwise adversely affect our results of operations, cash flows and the market value of our investments.” of our Annual Report on Form 10-K

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash on our consolidated balance sheets to the total amount shown on our consolidated statements of cash flows ($ in thousands): September 30, 2021 September 30, 2020 Cash and cash equivalents $ 211,180 $ 427,028 2021 FL4 CLO restricted cash 25,000 — Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows $ 236,180 $ 427,028
Schedule Of Cumulative Effective Adjustment To The Opening Retained Earnings	The following table details the impact of this adoption ($ in thousands): Impact of ASU 2016-13 Adoption Assets: Loans U.S. Loans $ 8,955 Non-U.S. 3,631 Unique Loans 1,356 CECL reserve on loans $ 13,942 CECL reserve on held-to-maturity 445 Liabilities: CECL reserve on unfunded loan commitments 3,263 Total impact of ASU 2016-13 $ 17,650

Loans Receivable, Net (Tables)

Loans Receivable, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Overall Statistics for Loans Receivable Portfolio	The following table details overall statistics for our loans receivable portfolio ($ in thousands): September 30, 2021 December 31, 2020 Number of loans 156 120 Principal balance $ 20,522,560 $ 16,652,824 Net book value $ 20,276,078 $ 16,399,166 Unfunded loan commitments (1) $ 4,220,214 $ 3,160,084 Weighted-average spread (2) + 3.18 % + 3.18 % Weighted-average all-in (2) + 3.51 % + 3.53 % Weighted-average maximum maturity (years) (3) 3.3 3.1 (1) Unfunded commitments will primarily be funded to finance our borrowers’ construction or development of real estate-related assets, capital improvements of existing assets, or lease-related expenditures. These commitments will generally be funded over the term of each loan, subject in certain cases to an expiration date. (2) The weighted-average spread and all-in all-in (3) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. As of September 30, 2021, 44% of our loans by principal balance were subject to yield maintenance or other prepayment restrictions and 56% were open to repayment by the borrower without penalty. As of December 31, 2020, 31% of our loans by principal balance were subject to yield maintenance or other prepayment restrictions and 69% were open to repayment by the borrower without penalty.
Schedule of Loan Receivable Portfolio Based On Floor Rate	The following table details the index rate floors for our loans receivable portfolio as of September 30, 2021 ($ in thousands): Loans Receivable Principal Balance Index rate floors USD Non-USD (1) Total Fixed rate $ — $ 78,511 $ 78,511 0.00% or no floor (2) 3,265,850 4,912,695 8,178,545 0.01% to 0.24% floor 3,910,133 112,026 4,022,159 0.25% to 0.99% floor 1,363,685 271,616 1,635,301 1.00% or more floor 6,062,597 545,447 6,608,044 Total (3)(4) $ 14,602,265 $ 5,920,295 $ 20,522,560 (1) Includes Euro, British Pound Sterling, Swedish Krona, Australian Dollar, and Canadian Dollar Currencies. (2) Includes $338.7 million of loans accounted for under the cost-recovery method. (3) Excludes investment exposure to $79.2 million subordinate position we own in the $493.3 million 2018 Single Asset Securitization. Refer to Notes 4 and 16 to our consolidated financial statements for further discussion of the 2018 Single Asset Securitization. (4) As of September 30, 2021, the weighted-average index rate floor of our loan portfolio was 0.55%. Excluding 0.0% index rate floors, the weighted-average index rate floor was 0.89%.
Activity Relating to Loans Receivable Portfolio	Activity relating to our loans receivable portfolio was as follows ($ in thousands): Principal Deferred Fees / (1) Net Book Loans receivable, as of December 31, 2020 $ 16,652,824 $ (80,109 ) $ 16,572,715 Loan fundings 7,449,491 — 7,449,491 Loan repayments and sales (3,351,118 ) — (3,351,118 ) Unrealized (loss) gain on foreign currency translation (228,637 ) 1,157 (227,480 ) Deferred fees and other items — (79,971 ) (79,971 ) Amortization of fees and other items — 42,829 42,829 Loans receivable, as of September 30, 2021 $ 20,522,560 $ (116,094 ) $ 20,406,466 CECL reserve (130,388 ) Loans receivable, net, as of September 30, 2021 $ 20,276,078 (1) Other items primarily consist of purchase and sale discounts or premiums, exit fees, and deferred origination expenses.
Property Type and Geographic Distribution of Properties Securing Loans in Portfolio	The tables below detail the property type and geographic distribution of the properties securing the loans in our portfolio ($ in thousands): September 30, 2021 Property Type Number of Net Book Total Loan (1)(2) Percentage of Office 65 $ 10,239,432 $ 10,940,778 50% Multifamily 56 4,465,938 4,494,065 21 Hospitality 18 2,777,827 2,879,888 13 Industrial 5 894,865 901,211 4 Retail 6 770,045 773,491 4 Life Sciences 2 407,595 413,209 2 Other 4 850,764 1,117,525 6 Total loans receivable 156 $ 20,406,466 $ 21,520,167 100% CECL reserve (130,388 ) Loans receivable, net $ 20,276,078 Geographic Location Number of Net Book Total Loan (1)(2) Percentage of United States Northeast 26 $ 4,463,202 $ 4,491,804 21% West 32 3,548,756 4,126,256 19 Southeast 33 3,425,624 3,618,296 17 Southwest 24 1,786,470 1,796,817 8 Midwest 10 1,201,663 1,205,877 6 Northwest 2 94,670 94,963 — Subtotal 127 14,520,385 15,334,013 71 International United Kingdom 14 1,754,872 1,999,180 9 Spain 4 1,448,355 1,455,967 7 Ireland 1 1,233,286 1,237,547 6 Sweden 1 564,277 569,529 3 Australia 2 175,786 176,144 1 Canada 2 66,881 66,864 — Other Europe 5 642,624 680,923 3 Subtotal 29 5,886,081 6,186,154 29 Total loans receivable 156 $ 20,406,466 $ 21,520,167 100% CECL reserve (130,388 ) Loans receivable, net $ 20,276,078 (1) In certain instances, we finance our loans through the non-recourse non-consolidated (2) Excludes investment exposure to the $493.3 million 2018 Single Asset Securitization. See Note 4 for details of the subordinate position we own in the 2018 Single Asset Securitization. December 31, 2020 Property Type Number of Net Book Total Loan (1)(2) Percentage of Office 58 $ 9,834,509 $ 10,303,895 58% Hospitality 14 2,295,255 2,369,454 14 Multifamily 31 1,788,149 1,862,667 11 Industrial 6 673,912 675,344 4 Retail 4 538,702 551,243 3 Life Sciences 1 146,290 147,763 1 Other 6 1,295,898 1,544,255 9 Total loans receivable 120 $ 16,572,715 $ 17,454,621 100% CECL reserve (173,549 ) Loans receivable, net $ 16,399,166 Geographic Location Number of Net Book Total Loan (1)(2) Percentage of United States Northeast 24 $ 4,050,732 $ 4,069,712 23% West 27 2,942,126 3,413,089 20 Southeast 25 2,624,701 2,707,080 16 Midwest 8 973,702 976,693 6 Southwest 9 597,100 598,813 3 Northwest 1 15,404 15,413 — Subtotal 94 11,203,765 11,780,800 68 International United Kingdom 13 1,816,901 2,066,390 12 Ireland 1 1,309,443 1,317,846 8 Spain 2 1,247,162 1,252,080 7 Australia 2 259,126 259,788 1 Canada 3 82,185 82,262 — Other Europe 5 654,133 695,455 4 Subtotal 26 5,368,950 5,673,821 32 Total loans receivable 120 $ 16,572,715 $ 17,454,621 100% CECL reserve (173,549 ) Loans receivable, net $ 16,399,166 (1) In certain instances, we finance our loans through the non-recourse non-consolidated (2) Excludes investment exposure to the $735.5 million 2018 Single Asset Securitization. See Note 4 for details of the subordinate position we own in the 2018 Single Asset Securitization.
Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings	The following table allocates the principal balance and net book value of our loans receivable based on our internal risk ratings ($ in thousands): September 30, 2021 December 31, 2020 Risk Rating Number of Loans Net Book Value Total Loan Exposure (1)(2) Number of Loans Net Book Value Total Loan Exposure (1)(2) 1 8 $ 931,330 $ 931,831 8 $ 777,163 $ 778,283 2 27 4,800,884 4,836,029 17 2,513,848 2,528,835 3 110 12,060,623 13,129,870 79 9,911,914 10,763,496 4 9 2,276,394 2,283,701 14 3,032,593 3,045,309 5 2 337,235 338,736 2 337,197 338,698 Total loans receivable 156 $ 20,406,466 $ 21,520,167 120 $ 16,572,715 $ 17,454,621 CECL reserve (130,388 ) (173,549 ) Loans receivable, net $ 20,276,078 $ 16,399,166 (1) In certain instances, we finance our loans through the non-recourse non-consolidated (2) Excludes investment exposure to the 2018 Single Asset Securitization of $493.3 million and $735.5 million as of September 30, 2021 and December 31, 2020, respectively. See Note 4 for details of the subordinate position we own in the 2018 Single Asset Securitization.
Schedule Of Current Expected Credit Loss Reserve By Pool	The following table presents the activity in our loans receivable CECL reserve by investment pool for the three and nine months ended September 30, 2021 and 2020 ($ in thousands): U.S. Loans Non-U.S. Loans Unique Loans Impaired Loans Total Loans Receivable, Net CECL reserve as of December 31, 2020 $ 42,995 $ 27,734 $ 33,159 $ 69,661 $ 173,549 Increase (decrease) in CECL reserve 1,539 (3,134 ) 146 — (1,449 ) CECL reserve as of March 31, 2021 $ 44,534 $ 24,600 $ 33,305 $ 69,661 $ 172,100 Decrease in CECL reserve (26,861 ) (15,771 ) (523 ) — (43,155 ) CECL reserve as of June 30, 2021 $ 17,673 $ 8,829 $ 32,782 $ 69,661 $ 128,945 Increase (decrease) in CECL reserve 3,253 (283 ) (1,527 ) — 1,443 CECL reserve as of September 30, 2021 $ 20,926 $ 8,546 $ 31,255 $ 69,661 $ 130,388 CECL reserve as of December 31, 2019 $ — $ — $ — $ — $ — Initial CECL reserve on January 1, 2020 8,955 3,631 1,356 — 13,942 Increase in CECL reserve 55,906 18,194 24,652 — 98,752 CECL reserve as of March 31, 2020 $ 64,861 $ 21,825 $ 26,008 $ — $ 112,694 (Decrease) increase in CECL reserve (3,457 ) (2,080 ) 1,232 69,661 65,356 CECL reserve as of June 30, 2020 $ 61,404 $ 19,745 $ 27,240 $ 69,661 $ 178,050 (Decrease) increase in CECL reserve (10,762 ) 7,035 2,703 — (1,024 ) CECL reserve as of September 30, 2020 $ 50,642 $ 26,780 $ 29,943 $ 69,661 $ 177,026
Schedule of Loans Receivable Based On Our Internal Risk Ratings, Separated By Year Of Origination	The following tables present the net book value of our loan portfolio as of September 30, 2021 and December 31, 2020, respectively, by year of origination, investment pool, and risk rating ($ in thousands): Net Book Value of Loans Receivable by Year of Origination (1)(2) As of September 30, 2021 Risk Rating 2021 2020 2019 2018 2017 Prior Total U.S. loans 1 $ — $ 43,745 $ 696,764 $ — $ 66,188 $ — $ 806,697 2 694,114 — 586,976 887,935 391,740 81,256 2,642,021 3 4,979,207 830,399 1,844,466 1,522,591 602,976 269,127 10,048,766 4 — — 96,494 540,766 63,365 51,923 752,548 5 — — — — — — — Total U.S. loans $ 5,673,321 $ 874,144 $ 3,224,700 $ 2,951,292 $ 1,124,269 $ 402,306 $ 14,250,032 Non-U.S. 1 $ — $ — $ 34,877 $ — $ 89,756 $ — $ 124,633 2 564,277 100,126 1,383,692 — — 110,768 2,158,863 3 455,534 — 907,728 393,573 — — 1,756,835 4 — — 346,071 — — — 346,071 5 — — — — — — — Total Non-U.S. $ 1,019,811 $ 100,126 $ 2,672,368 $ 393,573 $ 89,756 $ 110,768 $ 4,386,402 Unique loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — — 196,073 — 58,949 255,022 4 — — 321,156 856,619 — — 1,177,775 5 — — — — — — — Total unique loans $ — $ — $ 321,156 $ 1,052,692 $ — $ 58,949 $ 1,432,797 Impaired loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — — — — — — 4 — — — — — — — 5 — — — 284,808 — 52,427 337,235 Total impaired loans $ — $ — $ — $ 284,808 $ — $ 52,427 $ 337,235 Total loans receivable 1 $ — $ 43,745 $ 731,641 $ — $ 155,944 $ — $ 931,330 2 1,258,391 100,126 1,970,668 887,935 391,740 192,024 4,800,884 3 5,434,741 830,399 2,752,194 2,112,237 602,976 328,076 12,060,623 4 — — 763,721 1,397,385 63,365 51,923 2,276,394 5 — — — 284,808 — 52,427 337,235 Total loans receivable $ 6,693,132 $ 974,270 $ 6,218,224 $ 4,682,365 $ 1,214,025 $ 624,450 $ 20,406,466 CECL reserve (130,388 ) Loans receivable, net $ 20,276,078 (1) Date loan was originated or acquired by us. Origination dates are subsequently updated to reflect material loan modifications. (2) Excludes the $77.6 million net book value of our held-to-maturity Net Book Value of Loans Receivable by Year of Origination (1)(2) As of December 31, 2020 Risk Rating 2020 2019 2018 2017 2016 Prior Total U.S. loans 1 $ — $ 231,796 $ 253,674 $ 43,906 $ 17,009 $ — $ 546,385 2 — 282,017 1,172,168 757,138 79,848 222,677 2,513,848 3 781,595 2,391,297 1,672,897 1,134,288 227,466 220,644 6,428,187 4 65,978 170,541 1,055,142 63,293 105,380 — 1,460,334 5 — — — — — — — Total U.S. loans $ 847,573 $ 3,075,651 $ 4,153,881 $ 1,998,625 $ 429,703 $ 443,321 $ 10,948,754 Non-U.S. 1 $ — $ — $ 136,021 $ 94,757 $ — $ — $ 230,778 2 — — — — — — — 3 105,300 2,526,225 479,512 — 113,653 — 3,224,690 4 — 256,494 — — — — 256,494 5 — — — — — — — Total Non-U.S. $ 105,300 $ 2,782,719 $ 615,533 $ 94,757 $ 113,653 $ — $ 3,711,962 Unique loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — 198,433 — — 60,604 259,037 4 — 325,097 990,668 — — — 1,315,765 5 — — — — — — — Total unique loans $ — $ 325,097 $ 1,189,101 $ — $ — $ 60,604 $ 1,574,802 Impaired loans 1 $ — $ — $ — $ — $ — $ — $ — 2 — — — — — — — 3 — — — — — — — 4 — — — — — — — 5 — — 284,809 — — 52,388 337,197 Total impaired loans $ — $ — $ 284,809 $ — $ — $ 52,388 $ 337,197 Total loans receivable 1 $ — $ 231,796 $ 389,695 $ 138,663 $ 17,009 $ — $ 777,163 2 — 282,017 1,172,168 757,138 79,848 222,677 2,513,848 3 886,895 4,917,522 2,350,842 1,134,288 341,119 281,248 9,911,914 4 65,978 752,132 2,045,810 63,293 105,380 — 3,032,593 5 — — 284,809 — — 52,388 337,197 Total loans receivable $ 952,873 $ 6,183,467 $ 6,243,324 $ 2,093,382 $ 543,356 $ 556,313 $ 16,572,715 CECL reserve (173,549 ) Loans receivable, net $ 16,399,166 (1) Date loan was originated or acquired by us. Origination dates are subsequently updated to reflect material loan modifications. (2) Excludes the $75.7 million net book value of our held-to-maturity

Other Assets and Liabilities (T

Other Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Summary of Components of Other Assets	The following table details the components of our other assets ($ in thousands): September 30, 2021 December 31, 2020 Accrued interest receivable $ 78,689 $ 66,757 Debt securities held-to-maturity (1) 77,916 77,445 CECL reserve (280 ) (1,723 ) Debt securities held-to-maturity, 77,636 75,722 Derivative assets 35,858 522 2021 FL4 CLO restricted cash (2) 25,000 — Loan portfolio payments held by servicer (3) 766 73,224 Prepaid expenses 43 973 Collateral deposited under derivative agreements — 51,050 Prepaid taxes — 376 Other 622 1,195 Total $ 218,614 $ 269,819 (1) Represents the subordinate position we own in the 2018 Single Asset Securitization, which held aggregate loan assets of $493.3 million and $735.5 million as of September 30, 2021 and December 31, 2020, respectively, with a yield to full maturity of L+10.0% and a maximum maturity date of June 9, 2025, assuming all extension options are exercised by the borrower. Refer to Note 16 for additional discussion. (2) Represents $25.0 million of restricted cash held by our 2021 FL4 collateralized loan obligation that can be used to acquire and finance additional assets for up to six months from the date of closing. (3) Represents loan principal and interest payments held by our third-party loan servicer as of the balance sheet date which were remitted to us during the subsequent remittance cycle.
Schedule Of Current Expected Credit Loss Reserve By Pool	The following table presents the activity in our loans receivable CECL reserve by investment pool for the three and nine months ended September 30, 2021 and 2020 ($ in thousands): U.S. Loans Non-U.S. Loans Unique Loans Impaired Loans Total Loans Receivable, Net CECL reserve as of December 31, 2020 $ 42,995 $ 27,734 $ 33,159 $ 69,661 $ 173,549 Increase (decrease) in CECL reserve 1,539 (3,134 ) 146 — (1,449 ) CECL reserve as of March 31, 2021 $ 44,534 $ 24,600 $ 33,305 $ 69,661 $ 172,100 Decrease in CECL reserve (26,861 ) (15,771 ) (523 ) — (43,155 ) CECL reserve as of June 30, 2021 $ 17,673 $ 8,829 $ 32,782 $ 69,661 $ 128,945 Increase (decrease) in CECL reserve 3,253 (283 ) (1,527 ) — 1,443 CECL reserve as of September 30, 2021 $ 20,926 $ 8,546 $ 31,255 $ 69,661 $ 130,388 CECL reserve as of December 31, 2019 $ — $ — $ — $ — $ — Initial CECL reserve on January 1, 2020 8,955 3,631 1,356 — 13,942 Increase in CECL reserve 55,906 18,194 24,652 — 98,752 CECL reserve as of March 31, 2020 $ 64,861 $ 21,825 $ 26,008 $ — $ 112,694 (Decrease) increase in CECL reserve (3,457 ) (2,080 ) 1,232 69,661 65,356 CECL reserve as of June 30, 2020 $ 61,404 $ 19,745 $ 27,240 $ 69,661 $ 178,050 (Decrease) increase in CECL reserve (10,762 ) 7,035 2,703 — (1,024 ) CECL reserve as of September 30, 2020 $ 50,642 $ 26,780 $ 29,943 $ 69,661 $ 177,026
Summary of Components of Other Liabilities	The following table details the components of our other liabilities ($ in thousands): September 30, 2021 December 31, 2020 Accrued dividends payable $ 97,350 $ 91,004 Accrued interest payable 25,772 20,548 Accrued management and incentive fees payable 19,342 19,158 Accounts payable and other liabilities 11,080 2,671 Current expected credit loss reserve for unfunded loan commitments (1) 5,203 10,031 Derivative liabilities 355 58,915 Secured debt repayments pending servicer remittance (2) 322 — Total $ 159,424 $ 202,327 (1) Represents the CECL reserve related to our unfunded loan commitments. See Note 2 for further discussion of the CECL reserve. (2) Represents pending transfers from our third-party loan servicer that were remitted to our banking counterparties during the subsequent remittance cycle.
Schedule of Unfunded Loan Commitments Reserve	The following table presents the activity in the CECL reserve related to our unfunded loan commitments by investment pool for the three and nine months ended September 30, 2021 and 2020 ($ in thousands): U.S. Loans Non-U.S. Loans Unique Loans Impaired Loans Total Unfunded Loan Commitments CECL reserve as of December 31, 2020 $ 6,953 $ 2,994 $ 84 $ — $ 10,031 Increase (decrease) in CECL reserve 216 778 (4 ) — 990 CECL reserve as of March 31, 2021 $ 7,169 $ 3,772 $ 80 $ — $ 11,021 Decrease in CECL reserve (4,315 ) (2,632 ) (37 ) — (6,984 ) CECL reserve as of June 30, 2021 $ 2,854 $ 1,140 $ 43 $ — $ 4,037 Increase (decrease) in CECL reserve 566 643 (43 ) — 1,166 CECL reserve as of September 30, 2021 $ 3,420 $ 1,783 $ — $ — $ 5,203 CECL reserve as of December 31, 2019 $ — $ — $ — $ — $ — Initial CECL reserve on January 1, 2020 2,801 453 9 — 3,263 Increase in CECL reserve 16,992 2,219 62 — 19,273 CECL reserve as of March 31, 2020 $ 19,793 $ 2,672 $ 71 $ — $ 22,536 (Decrease) increase in CECL reserve (6,957 ) (594 ) 17 — (7,534 ) CECL reserve as of June 30, 2020 $ 12,836 $ 2,078 $ 88 $ — $ 15,002 (Decrease) increase in CECL reserve (3,657 ) 732 (20 ) — (2,945 ) CECL reserve as of September 30, 2020 $ 9,179 $ 2,810 $ 68 $ — $ 12,057
Held To Maturity Debt Securities [Member]
Schedule Of Current Expected Credit Loss Reserve By Pool	The following table presents the activity in our debt securities CECL reserve by investment pool for the three and nine months ended September 30, 2021 and 2020 ($ in thousands): Debt Securities Held-To-Maturity CECL reserve as of December 31, 2020 $ 1,723 Decrease in CECL reserve (834 ) CECL reserve as of March 31, 2021 $ 889 Decrease in CECL reserve (767 ) CECL reserve as of June 30, 2021 $ 122 Increase in CECL reserve 158 CECL reserve as of September 30, 2021 $ 280 CECL reserve as of December 31, 2019 $ — Initial CECL reserve on January 1, 2020 445 Increase in CECL reserve 4,677 CECL reserve as of March 31, 2020 $ 5,122 Decrease in CECL reserve (1,003 ) CECL reserve as of June 30, 2020 $ 4,119 Decrease in CECL reserve (2,086 ) CECL reserve as of September 30, 2020 $ 2,033

Secured Debt , Net (Tables)

Secured Debt , Net (Tables)	9 Months Ended
	Sep. 30, 2021
Schedule of Secured Debt Agreements	The following table details our secured debt ($ in thousands): Secured Debt Borrowings Outstanding September 30, 2021 December 31, 2020 Secured credit facilities $ 11,188,855 $ 7,896,863 Acquisition facility — — Total secured debt $ 11,188,855 $ 7,896,863 Deferred financing costs (1) (18,525 ) (16,327 ) Net book value of secured debt $ 11,170,330 $ 7,880,536 (1) Costs incurred in connection with our secured debt are recorded on our consolidated balance sheet when incurred and recognized as a component of interest expense over the life of each related facility.
Schedule of Secured Credit Facilities	The following table details our secured credit facilities as of September 30, 2021 ($ in thousands): September 30, 2021 Wtd Avg. Wtd Avg. Recourse Limitation Currency Lenders (1) Borrowings Maturity (2) Loan Count Collateral (3) Maturity (4) Wtd. Avg. Range USD 12 $ 7,022,125 5/5/2025 114 $ 9,557,168 5/1/2025 29% 25% - 100% EUR 6 2,369,013 7/26/2024 10 3,150,165 7/4/2024 48% 25% - 100% GBP 6 1,163,414 10/22/2024 12 1,739,121 11/9/2024 26% 25% - 50% Others (5) 4 634,303 6/17/2025 5 812,537 5/28/2025 27% 25% - 100% Total 12 $ 11,188,855 2/17/2025 141 $ 15,258,991 2/10/2025 32% 25% - 100% (1) Represents the number of lenders with fundings advanced in each respective currency, as well as the total number of facility lenders. (2) Based on the earlier of (i) the maximum maturity date of each secured credit facility, or (ii) the maximum maturity date of the collateral loans. (3) Represents the principal balance of the collateral assets. (4) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. (5) Includes Swedish Krona, Australian Dollar, and Canadian Dollar currencies.
Schedule of All in Cost of Secured Credit Facilities	The following tables detail the spread of our secured credit facilities as of September 30, 2021 and December 31, 2020 ($ in thousands): Nine Months Ended September 30, 2021 Spread (1) New Financings (2) Total Borrowings Wtd. Avg. All-in Cost (1)(3)(4) Collateral (5) Wtd. Avg. All-in Yield (1)(6) Net Interest (7) + 1.50% or less $ 3,065,115 $ 6,288,807 + 1.54 % $ 8,176,251 + 3.09 % + 1.55 % + 1.51% to + 1.75% 1,268,796 2,780,867 + 1.88 % 3,851,597 + 3.40 % + 1.52 % + 1.76% to + 2.00% 479,767 897,258 + 2.08 % 1,253,906 + 3.95 % + 1.87 % + 2.01% or more 465,872 1,221,923 + 2.42 % 1,977,237 + 4.42 % + 2.00 % Total $ 5,279,550 $ 11,188,855 + 1.77 % $ 15,258,991 + 3.41 % + 1.64 % Year Ended December 31, 2020 Spread (1) New Financings (2) Total Borrowings Wtd. Avg. All-in Cost (1)(3)(4) Collateral (5) Wtd. Avg. All-in Yield (1)(6) Net Interest Margin (7) + 1.50% or less $ 376,085 $ 4,192,280 + 1.59 % $ 6,338,626 + 3.09 % + 1.50 % + 1.51% to + 1.75% 172,447 1,945,692 + 1.95 % 2,975,581 + 3.43 % + 1.48 % + 1.76% to + 2.00% 215,056 926,666 + 2.06 % 1,212,546 + 3.83 % + 1.77 % + 2.01% or more 134,928 832,225 + 2.49 % 1,514,154 + 4.34 % + 1.85 % Total $ 898,516 $ 7,896,863 + 1.83 % $ 12,040,907 + 3.40 % + 1.57 % (1) The spread, all-in all-in (2) Represents borrowings outstanding as of September 30, 2021 and December 31, 2020, respectively, for new financings during the nine months ended September 30, 2021 and year ended December 31, 2020, respectively, based on the date collateral was initially pledged to each credit facility. (3) In addition to spread, the cost includes the associated deferred fees and expenses related to the respective borrowings. (4) Represents the weighted-average all-in (5) Represents the principal balance of the collateral assets. (6) In addition to cash coupon, all-in (7) Represents the difference between the weighted-average all-in all-in

Securitized Debt Obligations,_2

Securitized Debt Obligations, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Schedule of Information on Securitized Debt Obligations	The following tables detail our securitized debt obligations ($ in thousands): September 30, 2021 Securitized Debt Obligations Count Principal Balance Book Value Wtd. Avg. (1) (2) Term (3) 2021 FL4 Collateralized Loan Obligation Collateral assets 35 $ 1,000,000 $ 1,000,000 + 3.41 % July 2024 Financing provided 1 803,750 796,864 + 1.65 % May 2038 2020 FL3 Collateralized Loan Obligation Collateral assets 21 1,000,000 1,000,000 + 3.02 % April 2024 Financing provided (2) 1 808,750 803,378 + 2.10 % November 2037 2020 FL2 Collateralized Loan Obligation Collateral assets 24 1,500,000 1,500,000 + 3.10 % March 2024 Financing provided (2) 1 1,243,125 1,235,807 + 1.45 % February 2038 Total Collateral assets 80 $ 3,500,000 $ 3,500,000 + 3.17 % Financing provided (4) 3 $ 2,855,625 $ 2,836,049 + 1.69 % (1) In addition to cash coupon, all-in (2) The weighted-average all-in 30-day 30-day one-month (3) Loan term represents weighted-average final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitizations. (4) During the three and nine months ended September 30, 2021, we recorded $10.7 million and $35.2 million, respectively, of interest expense related to our securitized debt obligations. December 31, 2020 Securitized Debt Obligations Count Principal Book Value Wtd. Avg. (1) (2) Term (3) 2020 FL3 Collateralized Loan Obligation Collateral assets 25 $ 1,000,000 $ 1,000,000 + 3.09 % February 2024 Financing provided 1 808,750 800,993 + 2.08 % November 2037 2020 FL2 Collateralized Loan Obligation Collateral assets 31 1,500,000 1,500,000 + 3.17 % January 2024 Financing provided 1 1,243,125 1,233,464 + 1.44 % February 2038 2017 FL1 Collateralized Loan Obligation Collateral assets 15 666,334 666,334 + 3.39 % January 2023 Financing provided 1 483,834 483,113 + 1.83 % June 2035 2017 Single Asset Securitization Collateral assets (4) 1 619,194 618,766 + 3.57 % June 2023 Financing provided 1 404,929 404,929 + 1.63 % June 2033 Total Collateral assets 72 $ 3,785,528 $ 3,785,100 + 3.25 % Financing provided (5) 4 $ 2,940,638 $ 2,922,499 + 1.70 % (1) In addition to cash coupon, all-in (2) The weighted-average all-in (3) Loan term represents weighted-average final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitizations. (4) The collateral assets for the 2017 Single Asset Securitization include the total loan amount, of which we securitized $500.0 million. (5) During the three and nine months ended September 30, 2020, we recorded $9.1 million and $31.8 million, respectively, of interest expense related to our securitized debt obligations.

Asset-Specific Debt, Net (Table

Asset-Specific Debt, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Summary of Asset-Specific Financings	The following tables detail our asset-specific debt ($ in thousands): September 30, 2021 Asset-Specific Debt Count Principal Balance Book Value Wtd. Avg. Yield/Cost (1) Wtd. Avg. Term (2) Collateral assets 3 $ 436,562 $ 424,650 + 4.34 % Dec. 2024 Financing provided 3 $ 328,068 $ 320,895 + 3.13 % Dec. 2024 December 31, 2020 Asset-Specific Debt Count Principal Balance Book Value Wtd. Avg. Yield/Cost (1) Wtd. Avg. Term (2) Collateral assets 4 $ 512,794 $ 499,085 + 4.65 % Oct. 2023 Financing provided 4 $ 399,699 $ 391,269 + 3.48 % Oct. 2023 (1) These floating rate loans and related liabilities are indexed to the various benchmark rates relevant in each arrangement in terms of currency and payment frequency. Therefore the net exposure to each benchmark rate is in direct proportion to our net assets indexed to that rate. In addition to cash coupon, yield/cost includes the amortization of deferred origination fees / financing costs. (2) The weighted-average term is determined based on the maximum maturity of the corresponding loans, assuming all extension options are exercised by the borrower. Each of our asset-specific debt is term-matched to the corresponding collateral loans.

Term Loans, Net (Tables)

Term Loans, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Line Items]
Schedule of Debt	The following table details our secured credit facilities as of September 30, 2021 ($ in thousands): September 30, 2021 Wtd Avg. Wtd Avg. Recourse Limitation Currency Lenders (1) Borrowings Maturity (2) Loan Count Collateral (3) Maturity (4) Wtd. Avg. Range USD 12 $ 7,022,125 5/5/2025 114 $ 9,557,168 5/1/2025 29% 25% - 100% EUR 6 2,369,013 7/26/2024 10 3,150,165 7/4/2024 48% 25% - 100% GBP 6 1,163,414 10/22/2024 12 1,739,121 11/9/2024 26% 25% - 50% Others (5) 4 634,303 6/17/2025 5 812,537 5/28/2025 27% 25% - 100% Total 12 $ 11,188,855 2/17/2025 141 $ 15,258,991 2/10/2025 32% 25% - 100% (1) Represents the number of lenders with fundings advanced in each respective currency, as well as the total number of facility lenders. (2) Based on the earlier of (i) the maximum maturity date of each secured credit facility, or (ii) the maximum maturity date of the collateral loans. (3) Represents the principal balance of the collateral assets. (4) Maximum maturity assumes all extension options are exercised by the borrower, however our loans may be repaid prior to such date. (5) Includes Swedish Krona, Australian Dollar, and Canadian Dollar currencies.
Schedule of Net Book Value of Our Term Loans on Our Consolidated Balance Sheets	The following table details the net book value of our Convertible Notes on our consolidated balance sheets ($ in thousands): September 30, 2021 December 31, 2020 Face value $ 622,500 $ 622,500 Unamortized discount (3,301 ) (5,715 ) Deferred financing costs (214 ) (396 ) Net book value $ 618,985 $ 616,389
Term Loan [Member]
Debt Disclosure [Line Items]
Schedule of Debt	As of September 30, 2021, the following senior term loan facilities, or Term Loans, were outstanding ($ in thousands): Term Loans Face Value Interest Rate (1) All-in Cost (1)(2) Maturity B-1 $ 932,256 + 2.25 % + 2.53 % April 23, 2026 B-2 $ 420,450 + 2.75 % + 3.42 % April 23, 2026 (1) The B-2 (2) Includes issue discount and transaction expenses that are amortized through interest expense over the life of the Term Loans.
Schedule of Net Book Value of Our Term Loans on Our Consolidated Balance Sheets	The following table details the net book value of our Term Loans on our consolidated balance sheets ($ in thousands): September 30, 2021 December 31, 2020 Face value $ 1,352,706 $ 1,062,766 Unamortized discount (9,748 ) (9,807 ) Deferred financing costs (13,321 ) (11,255 ) Net book value $ 1,329,637 $ 1,041,704

Convertible Notes, Net (Tables)

Convertible Notes, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Summary of Outstanding Convertible Senior Notes	As of September 30, 2021, the following convertible senior notes, or Convertible Notes, were outstanding ($ in thousands): Convertible Notes Face Value Interest Rate All-in Cost (1) Conversion Rate (2) Maturity May 2017 $ 402,500 4.38 % 4.85 % 28.0324 May 5, 2022 March 2018 $ 220,000 4.75 % 5.33 % 27.6052 March 15, 2023 (1) Includes issuance costs that are amortized through interest expense over the life of the Convertible Notes using the effective interest method. (2) Represents the shares of class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to a conversion price of $35.67 and $36.23 per share of class A common stock, respectively, for the May 2017 and March 2018 convertible notes. The cumulative dividend threshold as defined in the respective May 2017 and March 2018 convertible notes supplemental indentures have not been exceeded as of September 30, 2021.
Summary of Details of Net Book Value of Convertible Note	The following table details the net book value of our Convertible Notes on our consolidated balance sheets ($ in thousands): September 30, 2021 December 31, 2020 Face value $ 622,500 $ 622,500 Unamortized discount (3,301 ) (5,715 ) Deferred financing costs (214 ) (396 ) Net book value $ 618,985 $ 616,389
Summary of Details about Interest Expense	The following table details our interest expense related to the Convertible Notes ($ in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2021 2020 2021 2020 Cash coupon $ 7,015 $ 7,015 $ 21,045 $ 21,045 Discount and issuance cost amortization 873 831 2,595 2,470 Total interest expense $ 7,888 $ 7,846 $ 23,640 $ 23,515

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk	The following tables detail our outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk (notional amount in thousands): September 30, 2021 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Caps 1 C$ 21,020 1.0 % CDOR 0.2 December 31, 2020 Interest Rate Derivatives Number of Notional Strike Index Wtd.-Avg. Interest Rate Caps 2 C$ 38,293 1.0 % CDOR 0.8
Summary of Outstanding Foreign Exchange Derivatives Designated as Net Investment Hedges of Foreign Currency Risk	The following table details our outstanding foreign exchange derivatives that were designated as net investment hedges of foreign currency risk (notional amount in thousands): September 30, 2021 December 31, 2020 Foreign Currency Derivatives Number of Notional Amount Foreign Currency Derivatives Number of Instruments Notional Amount Buy USD / Sell SEK Forward 1 kr 999,500 Buy USD / Sell EUR Forward 8 € 754,722 Buy USD / Sell EUR Forward 6 € 817,642 Buy USD / Sell GBP Forward 4 € 372,487 Buy USD / Sell GBP Forward 1 £ 542,551 Buy USD / Sell AUD Forward 1 A$ 92,800 Buy USD / Sell AUD Forward 1 A$ 89,500 Buy USD / Sell CAD Forward 1 C$ 26,200 Buy USD / Sell CAD Forward 1 C$ 21,000
Summary of Non-designated Hedges	The following table details our outstanding foreign exchange derivatives that were non-designated September 30, 2021 December 31, 2020 Non-designated Number of Notional Non-designated Number of Notional Buy GBP / Sell EUR Forward 1 € 8,410 Buy EUR / Sell GBP Forward 2 £ 146,207 Buy EUR / Sell USD Forward 1 € 13,900 Buy USD / Sell EUR Forward 1 € 8,410 Buy USD / Sell EUR Forward 1 € 13,900
Schedule of Derivative Instruments Gain Loss in Statement of Operations	The following table presents the effect of our derivative financial instruments on our consolidated statements of operations ($ in thousands): Increase (Decrease) to Net Interest Income from Foreign Exchange Contracts Three Months Three Months Nine Months Nine Months Foreign Exchange Contracts Location of Income Ended Ended Ended Ended in Hedging Relationships (Expense) Recognized September 30, 2021 September 30, 2020 September 30, 2021 September 30, 2020 Designated Hedges Interest Income (1) $ 1,542 $ 1,794 $ 5,294 $ 2,303 Non-Designated Interest Income (1) 34 (227 ) (340 ) (222 ) Non-Designated Interest Expense (2) (8 ) 669 (7,139 ) (846 ) Total $ 1,568 $ 2,236 $ (2,185 ) $ 1,235 (1) Represents the forward points earned on our foreign currency forward contracts, which reflect the interest rate differentials between the applicable base rate for our foreign currency investments and USD LIBOR. These forward contracts effectively convert the rate exposure to USD LIBOR, resulting in additional interest income earned in U.S. dollar terms. (2) Represents the spot rate movement in our non-designated marked-to-market
Summary of Fair Value of Derivative Financial Instruments	The following table summarizes the fair value of our derivative financial instruments ($ in thousands): Fair Value of Derivatives in an Asset Position (1) Fair Value of Derivatives in a Liability Position (2) September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Derivatives designated as hedging instruments: Foreign exchange contracts $ 35,460 $ 521 $ — $ 55,758 Interest rate derivatives — 1 — — Total $ 35,460 $ 522 $ — $ 55,758 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 398 $ — $ 355 $ 3,157 Interest rate derivatives — — — — Total $ 398 $ — $ 355 $ 3,157 Total Derivatives $ 35,858 $ 522 $ 355 $ 58,915 (1) Included in other assets in our consolidated balance sheets. (2) Included in other liabilities in our consolidated balance sheets.
Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations	The following table presents the effect of our derivative financial instruments on our consolidated statements of operations ($ in thousands): Amount of Gain Recognized in OCI on Derivatives Location of Gain (Loss) Amount of Loss Reclassified from Accumulated OCI into Income Three Months Nine Months Reclassified from Accumulated Three Months Nine Months Derivatives in Ended Ended Ended Ended Hedging Relationships September 30, 2021 September 30, 2021 OCI into Income September 30, 2021 September 30, 2021 Net Investment Hedges Foreign exchange contracts (1) $ 46,078 $ 65,052 Interest Expense $ — $ — Cash Flow Hedges Interest rate derivatives — — Interest Expense (2) (5 ) (7 ) Total $ 46,078 $ 65,052 $ (5 ) $ (7 ) (1) During the three and nine months ended September 30, 2021, we received net cash settlements of $18.3 million and paid net cash settlements of $31.0 million, respectively, on our foreign currency forward contracts. Those amounts are included as a component of accumulated other comprehensive income (loss) on our consolidated balance sheets. (2) During the three months ended September 30, 2021, we recorded total interest and related expenses of $82.7 million, which included interest expense of $5,000 related to our cash flow hedges. During the nine months ended September 30, 2021, we recorded total interest and related expenses of $243.4 million, which included interest expense of $7,000.

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Summary of Class A Common Stock Issuances	The following table details our issuances of class A common stock during the nine months ended September 30, 2021 ($ in thousands, except share and per share data): Class A Common Stock Offerings September 2021 Shares issued 10,000,000 Gross / net issue price per share (1) $31.45 / $31.24 Net proceeds (2) $311,955 (1) Represents the gross price per share issued, as well as the net proceeds per share after underwriting or sales discounts and commissions. (2) Net proceeds represents proceeds received from the underwriters less applicable transaction costs.
Schedule of Movement in Outstanding Shares of Class A Common Stock, Restricted Class A Common Stock and Deferred Stock Units	The following table details the movement in our outstanding shares of class A common stock, including restricted class A common stock and deferred stock units: Nine Months Ended September 30, Common Stock Outstanding (1) 2021 2020 Beginning balance 147,086,722 135,263,728 Issuance of class A common stock (2) 10,001,429 10,842,295 Issuance of restricted class A common stock, net (3) 234,229 351,333 Issuance of deferred stock units 50,009 33,790 Ending balance 157,372,389 146,491,146 (1) Includes 356,700 and 293,856 deferred stock units held by members of our board of directors as of September 30, 2021 and 2020, respectively. (2) Includes 1,429 and 1,599 shares issued under our dividend reinvestment program during the nine months ended September 30, 2021 and 2020, respectively. (3) The amounts are net of 29,580 and 249 shares of restricted class A common stock forfeited under our stock-based incentive plans during the nine months ended September 30, 2021 and 2020, respectively. See Note 14 for further discussion of our stock-based incentive plans.
Schedule of Dividend Activity	The following table details our dividend activity ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Dividends declared per share of common stock $ 0.62 $ 0.62 $ 1.86 $ 1.86 Class A common stock dividends declared $ 97,350 $ 90,642 $ 279,659 $ 265,205 Deferred stock unit dividends declared 202 174 591 502 Total dividends declared $ 97,552 $ 90,816 $ 280,250 $ 265,707
Schedule of Basic and Diluted Earnings Per Share, or EPS, Based on Weighted-Average of Both Restricted and Unrestricted Class A Common Stock Outstanding	The following table sets forth the calculation of basic and diluted net income (loss) per share of class A common stock based on the weighted-average of both restricted and unrestricted class A common stock outstanding ($ in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net income (1) $ 83,757 $ 89,860 $ 295,254 $ 54,054 Weighted-average shares outstanding, basic and diluted 149,214,819 146,484,651 147,971,737 140,157,620 Per share amount, basic and diluted $ 0.56 $ 0.61 $ 2.00 $ 0.39 (1) Represents net income attributable to Blackstone Mortgage Trust.

Other Expenses (Tables)

Other Expenses (Tables)	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
Schedule of General and Administrative Expenses	General and administrative expenses consisted of the following ($ in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Professional services (1) $ 1,969 $ 1,715 $ 5,831 $ 5,130 Operating and other costs (1) 792 878 2,093 3,212 Subtotal 2,761 2,593 7,924 8,342 Non-cash Restricted class A common stock earned 7,907 8,524 23,762 25,603 Director stock-based compensation 173 125 422 375 Subtotal 8,080 8,649 24,184 25,978 Total general and administrative expenses $ 10,841 $ 11,242 $ 32,108 $ 34,320 (1) During the three and nine months ended September 30, 2021, we recognized an aggregate $110,000 and $543,000, respectively, of expenses related to our Multifamily Joint Venture. During the three and nine months ended September 30, 2020, we recognized an aggregate $293,000 and $869,000, respectively, of expenses related to our Multifamily Joint Venture.

Stock-Based Incentive Plans (Ta

Stock-Based Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Movement in Outstanding Shares of Restricted Class A Common Stock and Weighted-Average Grant Date Fair Value Per Share	The following table details the movement in our outstanding shares of restricted class A common stock and the weighted-average grant date fair value per share: Restricted Class A Weighted-Average Balance as of December 31, 2020 1,627,890 $ 33.14 Granted 263,809 26.16 Vested (718,799 ) 33.08 Forfeited (29,580 ) 31.52 Balance as of September 30, 2021 1,143,320 $ 31.60

Fair Values (Tables)

Fair Values (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table summarizes our assets and liabilities measured at fair value on a recurring basis ($ in thousands): September 30, 2021 December 31, 2020 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Derivatives $ — $ 35,858 $ — $ 35,858 $ — $ 522 $ — $ 522 Liabilities Derivatives $ — $ 355 $ — $ 355 $ — $ 58,915 $ — $ 58,915
Schedule of Details of Carrying Amount, Face Amount, and Fair Value of Financial Instruments	The following table details the book value, face amount, and fair value of the financial instruments described in Note 2 ($ in thousands): September 30, 2021 December 31, 2020 Book Face Fair Book Face Fair Value Amount Value Value Amount Value Financial assets Cash and cash equivalents $ 211,180 $ 211,180 $ 211,180 $ 289,970 $ 289,970 $ 289,970 Loans receivable, net 20,276,078 20,522,560 20,358,824 16,399,166 16,652,824 16,447,192 Debt securities held-to-maturity (1) 77,636 79,200 78,633 75,722 79,200 70,127 Financial liabilities Secured debt, net 11,170,330 11,188,855 11,188,855 7,880,536 7,896,863 7,896,863 Securitized debt obligations, net 2,836,049 2,855,625 2,855,589 2,922,499 2,940,638 2,923,489 Asset-specific debt, net 320,895 328,068 328,068 391,269 399,699 399,699 Term loans, net 1,329,637 1,352,706 1,343,771 1,041,704 1,062,766 1,053,060 Convertible notes, net 618,985 622,500 633,845 616,389 622,500 621,568 (1) Included in other assets on our consolidated balance sheets.

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Assets and Liabilities of Consolidated CLO and Single Asset Securitization VIE	The following table details the assets and liabilities of our consolidated CLOs and 2017 Single Asset Securitization VIEs ($ in thousands): September 30, 2021 December 31, 2020 Assets: Loans receivable $ 3,475,000 $ 3,520,130 Current expected credit loss reserve (4,044 ) (13,454 ) Loans receivable, net 3,470,956 3,506,676 Other assets 32,406 81,274 Total assets $ 3,503,362 $ 3,587,950 Liabilities: Securitized debt obligations, net $ 2,836,049 $ 2,922,499 Other liabilities 1,631 2,104 Total liabilities $ 2,837,680 $ 2,924,603

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Principal Contractual Obligations	Our contractual principal debt repayments as of September 30, 2021 were as follows ($ in thousands): Secured Asset-Specific Term Convertible Year Debt (1) Debt (1) Loans (2) Notes (3) Total (4) 2021 (remainder of the year) $ 130,668 $ — $ 3,436 $ — $ 134,104 2022 228,030 — 13,738 402,500 644,268 2023 1,834,836 149,896 13,738 220,000 2,218,470 2024 3,937,001 — 13,738 — 3,950,739 2025 1,231,023 178,172 13,738 — 1,422,933 2026 3,725,205 — 1,294,318 — 5,019,523 Thereafter 102,092 — — — 102,092 Total obligation $ 11,188,855 $ 328,068 $ 1,352,706 $ 622,500 $ 13,492,129 (1) The allocation of repayments under our secured debt and asset-specific debt is based on the earlier of (i) the maturity date of each agreement, or (ii) the maximum maturity date of the collateral loans, assuming all extension options are exercised by the borrower. (2) The Term Loans are partially amortizing, with an amount equal to 1.0% per annum of the principal balance due in quarterly installments. Refer to Note 8 for further details on our term loans. (3) Reflects the outstanding principal balance of Convertible Notes, excluding any potential conversion premium. Refer to Note 9 for further details on our Convertible Notes. (4) Total does not include $2.9 billion of consolidated securitized debt obligations, $997.6 million of non-consolidated non-consolidated

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2020	Sep. 30, 2021	Dec. 31, 2020	Apr. 30, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Joint venture capital contribution percentage				85.00%
Income accrual, description		Income accrual is generally suspended for loans at the earlier of the date at which payments become 90 days past due or when, in the opinion of our Manager, recovery of income and principal becomes doubtful.
Cash and cash equivalents, description		Cash and cash equivalents represent cash held in banks and liquid investments with original maturities of three months or less.
Borrower Escrows		$ 426.6	$ 384.6
SOFR [Member] | Credit Spread Option [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit spread adjustment rate		0.11%
Average compounded secured overnight financing rate		0.05%
USD LIBOR Rate [Member] | Credit Spread Option [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average compounded secured overnight financing rate		0.08%
Sterling Overnight Interbank Average Rate [Member] | Credit Spread Option [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Daily compounded sterling overnight interbank average rate		0.05%
GBP LIBOR Rate [Member] | Credit Spread Option [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Daily compounded sterling overnight interbank average rate		0.08%
Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in CECL reserve	$ 69.7
Level 3 [Member] | Fair Value, Nonrecurring [Member] | Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and lease receivable		$ 338.7
Level 3 [Member] | Minimum [Member] | Measurement Input, Cap Rate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Capitalisation rate of loans receivable		4.25%
Level 3 [Member] | Maximum [Member] | Measurement Input, Cap Rate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Capitalisation rate of loans receivable		4.80%
ASU 2020-06 [Member] | January 1, 2022 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Adjustment to additional paid in capital other one		$ 2.4
Decrease in accumulated deficit		$ 2
Walker and Dunlop [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Joint venture capital contribution percentage				15.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 211,180	$ 289,970	$ 427,028
2021 FL4 CLO restricted cash	25,000	0	0
Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows	$ 236,180	$ 289,970	$ 427,028	$ 150,090

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Impact of this Adoption (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	$ 130,388	$ 128,945	$ 172,100	$ 173,549	$ 177,026	$ 178,050	$ 112,694		$ 0
Current expected credit loss reserve	280	122	889	1,723	2,033	4,119	5,122		0
Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve								$ 13,942
Current expected credit loss reserve								445,000	445
Impact of ASU 2016-13 Adoption [Member] | Adoption of ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	17,650
Current expected credit loss reserve	445
CECL reserve on unfunded loan commitments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	5,203	4,037	11,021	10,031	12,057	15,002	22,536		0
CECL reserve on unfunded loan commitments [Member] | Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	3,300							3,263
CECL reserve on unfunded loan commitments [Member] | Impact of ASU 2016-13 Adoption [Member] | Adoption of ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	3,263
U.S. Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	20,926	17,673	44,534	42,995	50,642	61,404	64,861
U.S. Loans [Member] | Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve								8,955
U.S. Loans [Member] | Impact of ASU 2016-13 Adoption [Member] | Adoption of ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	8,955
U.S. Loans [Member] | CECL reserve on unfunded loan commitments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	3,420	2,854	7,169	6,953	9,179	12,836	19,793		0
U.S. Loans [Member] | CECL reserve on unfunded loan commitments [Member] | Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve								2,801
Non-U.S. Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	8,546	8,829	24,600	27,734	26,780	19,745	21,825
Non-U.S. Loans [Member] | Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve								3,631
Non-U.S. Loans [Member] | Impact of ASU 2016-13 Adoption [Member] | Adoption of ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	3,631
Non-U.S. Loans [Member] | CECL reserve on unfunded loan commitments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	1,783	1,140	3,772	2,994	2,810	2,078	2,672		0
Non-U.S. Loans [Member] | CECL reserve on unfunded loan commitments [Member] | Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve								453
Unique Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	31,255	32,782	33,305	33,159	29,943	27,240	26,008		0
Unique Loans [Member] | Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve								1,356
Unique Loans [Member] | Impact of ASU 2016-13 Adoption [Member] | Adoption of ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	1,356
Unique Loans [Member] | CECL reserve on unfunded loan commitments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	0	$ 43	$ 80	$ 84	$ 68	$ 88	$ 71		$ 0
Unique Loans [Member] | CECL reserve on unfunded loan commitments [Member] | Impact of ASU 2016-13 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve								$ 9
CECL reserve on loans [Member] | Impact of ASU 2016-13 Adoption [Member] | Adoption of ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserve	$ 13,942

Loans Receivable, Net - Overall

Loans Receivable, Net - Overall Statistics for Loans Receivable Portfolio (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)SecurityLoan	Dec. 31, 2020USD ($)SecurityLoan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	156	120
Principal balance	$ 20,522,560	$ 16,652,824
Net book value	20,276,078	16,399,166
Unfunded loan commitments	$ 20,406,466	$ 16,572,715
Loans Receivable [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	156	120
Principal balance	$ 20,522,560	$ 16,652,824
Net book value	20,276,078	16,399,166
Unfunded loan commitments	$ 20,406,466	$ 16,572,715
Weighted-average maximum maturity (years)	3 years 3 months 18 days	3 years 1 month 6 days
Loans Receivable [Member] | Unfunded Loan Commitment [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Unfunded loan commitments	$ 4,220,214	$ 3,160,084
Loans Receivable [Member] | LIBOR [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Weighted-average spread, rate	3.18%	3.18%
Weighted-average all-in yield, rate	3.51%	3.53%
Weighted-average spread, rate description	+ 3.18	+ 3.18
Weighted-average all-in yield, rate description	+ 3.51	+ 3.53

Loans Receivable, Net - Overa_2

Loans Receivable, Net - Overall Statistics for Loans Receivable Portfolio (Parenthetical) (Detail)	Sep. 30, 2021	Dec. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Percentage of Portfolio	100.00%	100.00%
Prepayment Restrictions Including Yield Maintenance Lock Out Provisions [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Percentage of Portfolio	44.00%	31.00%
Without Prepayment Restrictions [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Percentage of Portfolio	56.00%	69.00%
Floating Rate Mortgage [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Percentage of Portfolio	99.60%	99.40%
Fixed Rate Mortgage [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Percentage of Portfolio	0.40%

Loans Receivable, Net - Schedul

Loans Receivable, Net - Schedule Of Loan Receivable Portfolio Based On Floor Rate (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	$ 20,522,560	$ 16,652,824
Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	5,920,295
USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	14,602,265
Fixed rate
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	78,511
Fixed rate | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	78,511
Fixed rate | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	0
0.00% or no floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	8,178,545
0.00% or no floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	4,912,695
0.00% or no floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	3,265,850
0.01% to 0.24% floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	4,022,159
0.01% to 0.24% floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	112,026
0.01% to 0.24% floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	3,910,133
0.25% to 0.99% floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	1,635,301
0.25% to 0.99% floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	271,616
0.25% to 0.99% floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	1,363,685
1.00% or more floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	6,608,044
1.00% or more floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	545,447
1.00% or more floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	$ 6,062,597

Loans Receivable, Net - Sched_2

Loans Receivable, Net - Schedule Of Loan Receivable Portfolio Based On Floor Rate (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Mortgage loans on real estate accounted for under cost recovery method	$ 338.7
2018 Single Asset Securitization [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal amount outstanding of loans	493.3	$ 735.5
Single asset securitization principal amount subordinate position	$ 79.2
0.00% or no floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Floor rate percentage on loan portfolio	0.00%
0.01% to 0.24% floor | Maximum [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Floor rate percentage on loan portfolio	0.24%
0.01% to 0.24% floor | Minimum [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Floor rate percentage on loan portfolio	0.01%
0.25% to 0.99% floor | Maximum [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Floor rate percentage on loan portfolio	0.99%
0.25% to 0.99% floor | Minimum [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Floor rate percentage on loan portfolio	0.25%
0.25% to 0.99% floor | Weighted Average [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Floor rate percentage on loan portfolio	0.55%
Floor rate percentage on loan portfolio excluding zero point zero percentage	0.89%
1.00% or more floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Floor rate percentage on loan portfolio	1.00%

Loans Receivable, Net - Activit

Loans Receivable, Net - Activity Relating to Loans Receivable Portfolio (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans receivable, Beginning Balance Principal Balance	$ 16,652,824
Loan fundings Principal Balance	7,449,491
Loan repayments and sales Principal balance	(3,351,118)
Unrealized (loss) gain on foreign currency translation Principal Balance	(228,637)
Deferred fees and other items Principal Balance	0
Amortization of fees and other items Principal Balance	0
Loans receivable, Ending Balance Principal Balance	20,522,560
Loans receivable, Beginning Balance Deferred Fees/ Other Items	(80,109)
Loans repayments Principal Balance	0
Loan repayments and sales proceeds deferred fees and other items	0
Unrealized gain (loss) on foreign currency translation Deferred Fees/ Other Items	1,157
Deferred fees and other items Deferred Fees/ Other Items	(79,971)
Amortization of fees and other items Deferred Fees/ Other Items	42,829
Loans receivable, Ending Balance Deferred Fees/ Other Items	(116,094)
Loans receivable, Beginning Balance Net Book Value	16,572,715
Loan fundings Net Book Value	7,449,491
Loan repayments and sales proceeds	(3,351,118)
Unrealized gain (loss) on foreign currency translation Net Book Value	(227,480)
Deferred fees and other items Net Book Value	(79,971)
Amortization of fees and other items Net Book Value	42,829
Loans receivable, Ending Balance Net Book Value	20,406,466
CECL reserve	(130,388)	$ (128,945)	$ (172,100)	$ (173,549)	$ (177,026)	$ (178,050)	$ (112,694)	$ 0
Net book value of restructured loan	$ 20,276,078			$ 16,399,166

Loans Receivable, Net - Propert

Loans Receivable, Net - Property Type and Geographic Distribution of Properties Securing Loans in Portfolio (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)SecurityLoan	Dec. 31, 2020USD ($)SecurityLoan	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	156	120
Net Book Value	$ 20,406,466	$ 16,572,715
Total Loan Exposure	$ 21,520,167	$ 17,454,621
Percentage of Portfolio	100.00%	100.00%
CECL reserve	$ (130,388)	$ (173,549)	$ (128,945)	$ (172,100)	$ (177,026)	$ (178,050)	$ (112,694)	$ 0
Net book value of restructured loan	$ 20,276,078	$ 16,399,166
Office [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	65	58
Net Book Value	$ 10,239,432	$ 9,834,509
Total Loan Exposure	$ 10,940,778	$ 10,303,895
Percentage of Portfolio	50.00%	58.00%
Hospitality [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	18	14
Net Book Value	$ 2,777,827	$ 2,295,255
Total Loan Exposure	$ 2,879,888	$ 2,369,454
Percentage of Portfolio	13.00%	14.00%
Multifamily [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	56	31
Net Book Value	$ 4,465,938	$ 1,788,149
Total Loan Exposure	$ 4,494,065	$ 1,862,667
Percentage of Portfolio	21.00%	11.00%
Industrial [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	5	6
Net Book Value	$ 894,865	$ 673,912
Total Loan Exposure	$ 901,211	$ 675,344
Percentage of Portfolio	4.00%	4.00%
Life Sciences [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	2	1
Net Book Value	$ 407,595	$ 146,290
Total Loan Exposure	$ 413,209	$ 147,763
Percentage of Portfolio	2.00%	1.00%
Retail [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	6	4
Net Book Value	$ 770,045	$ 538,702
Total Loan Exposure	$ 773,491	$ 551,243
Percentage of Portfolio	4.00%	3.00%
Other [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	4	6
Net Book Value	$ 850,764	$ 1,295,898
Total Loan Exposure	$ 1,117,525	$ 1,544,255
Percentage of Portfolio	6.00%	9.00%
United States Northeast [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	26	24
Net Book Value	$ 4,463,202	$ 4,050,732
Total Loan Exposure	$ 4,491,804	$ 4,069,712
Percentage of Portfolio	21.00%	23.00%
United States West [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	32	27
Net Book Value	$ 3,548,756	$ 2,942,126
Total Loan Exposure	$ 4,126,256	$ 3,413,089
Percentage of Portfolio	19.00%	20.00%
United States Southeast [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	33	25
Net Book Value	$ 3,425,624	$ 2,624,701
Total Loan Exposure	$ 3,618,296	$ 2,707,080
Percentage of Portfolio	17.00%	16.00%
United States Midwest [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	10	8
Net Book Value	$ 1,201,663	$ 973,702
Total Loan Exposure	$ 1,205,877	$ 976,693
Percentage of Portfolio	6.00%	6.00%
United States Southwest [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	24	9
Net Book Value	$ 1,786,470	$ 597,100
Total Loan Exposure	$ 1,796,817	$ 598,813
Percentage of Portfolio	8.00%	3.00%
United States Northwest [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	2	1
Net Book Value	$ 94,670	$ 15,404
Total Loan Exposure	$ 94,963	$ 15,413
Percentage of Portfolio	0.00%	0.00%
United States [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	127	94
Net Book Value	$ 14,520,385	$ 11,203,765
Total Loan Exposure	$ 15,334,013	$ 11,780,800
Percentage of Portfolio	71.00%	68.00%
United Kingdom [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	14	13
Net Book Value	$ 1,754,872	$ 1,816,901
Total Loan Exposure	$ 1,999,180	$ 2,066,390
Percentage of Portfolio	9.00%	12.00%
Spain [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	4	2
Net Book Value	$ 1,448,355	$ 1,247,162
Total Loan Exposure	$ 1,455,967	$ 1,252,080
Percentage of Portfolio	7.00%	7.00%
Ireland [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	1	1
Net Book Value	$ 1,233,286	$ 1,309,443
Total Loan Exposure	$ 1,237,547	$ 1,317,846
Percentage of Portfolio	6.00%	8.00%
Sweden [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	1
Net Book Value	$ 564,277
Total Loan Exposure	$ 569,529
Percentage of Portfolio	3.00%
Australia [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	2	2
Net Book Value	$ 175,786	$ 259,126
Total Loan Exposure	$ 176,144	$ 259,788
Percentage of Portfolio	1.00%	1.00%
Canada [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	2	3
Net Book Value	$ 66,881	$ 82,185
Total Loan Exposure	$ 66,864	$ 82,262
Percentage of Portfolio	0.00%	0.00%
International [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	29	26
Net Book Value	$ 5,886,081	$ 5,368,950
Total Loan Exposure	$ 6,186,154	$ 5,673,821
Percentage of Portfolio	29.00%	32.00%
Other Europe [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	5	5
Net Book Value	$ 642,624	$ 654,133
Total Loan Exposure	$ 680,923	$ 695,455
Percentage of Portfolio	3.00%	4.00%

Loans Receivable, Net - Prope_2

Loans Receivable, Net - Property Type and Geographic Distribution of Properties Securing Loans in Portfolio (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Total loan exposure including senior interests	$ 997.6	$ 801.8
2018 Single Asset Securitization [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Single asset securitization principal amount	$ 493.3	$ 735.5

Loans Receivable, Net - Princip

Loans Receivable, Net - Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)SecurityLoan	Dec. 31, 2020USD ($)SecurityLoan	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	156	120
Net Book Value	$ 20,406,466	$ 16,572,715
Total Loan Exposure	21,520,167	17,454,621
CECL reserve	(130,388)	(173,549)	$ (128,945)	$ (172,100)	$ (177,026)	$ (178,050)	$ (112,694)	$ 0
Net book value of restructured loan	$ 20,276,078	$ 16,399,166
Risk Rating 1 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	8	8
Net Book Value	$ 931,330	$ 777,163
Total Loan Exposure	$ 931,831	$ 778,283
Risk Rating 2 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	27	17
Net Book Value	$ 4,800,884	$ 2,513,848
Total Loan Exposure	$ 4,836,029	$ 2,528,835
Risk Rating 3 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	110	79
Net Book Value	$ 12,060,623	$ 9,911,914
Total Loan Exposure	$ 13,129,870	$ 10,763,496
Risk Rating 4 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	9	14
Net Book Value	$ 2,276,394	$ 3,032,593
Total Loan Exposure	$ 2,283,701	$ 3,045,309
Risk Rating 5 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans | SecurityLoan	2	2
Net Book Value	$ 337,235	$ 337,197
Total Loan Exposure	$ 338,736	$ 338,698

Loans Receivable, Net - Princ_2

Loans Receivable, Net - Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Total loan exposure including senior interests	$ 997.6	$ 801.8
2018 Single Asset Securitization [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Single asset securitization principal amount	$ 493.3	$ 735.5

Loans Receivable, Net - Additio

Loans Receivable, Net - Additional Information (Detail) $ in Thousands	Jul. 01, 2020USD ($)	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Weighted-average risk rating on loan exposure		2.8						2.8		3
Loans held		$ 21,520,167						$ 21,520,167		$ 17,454,621
Net book value of restructured loan		20,276,078						20,276,078		16,399,166
CECL reserve		130,388	$ 128,945	$ 172,100	$ 177,026	$ 178,050	$ 112,694	130,388	$ 177,026	173,549		$ 0
(Decrease) Increase in CECL reserve		98,752	$ (43,155)	$ (1,449)	(1,024)	65,356	$ 1,443
Reduction In Loan Spread And Extension In Maturity Date [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing receivable troubled debt restructuring premodification recorded investment	$ 338,700
Financing receivable troubled debt restructuring premodification recorded investment income	$ 0
CECL Troubled Debt Restructuring Principal Amount Due Is 52.4 Million Dollars [Member] | Reduction In Loan Spread And Extension In Maturity Date [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Increase in CECL reserve						14,800
Financing receivable troubled debt restructuring premodification recorded investment								52,400
CECL Troubled Debt Restructuring Principal Amount Due Is 54.9 Million Dollars [Member] | Reduction In Loan Spread And Extension In Maturity Date [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Increase in CECL reserve						$ 54,900
Financing receivable troubled debt restructuring premodification recorded investment								286,300
COVID-19 pandemic [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Net book value of restructured loan		130,400			177,000			130,400	177,000
CECL reserve											$ 13,900
(Decrease) Increase in CECL reserve		(1,400)			$ (1,000)			(43,200)	$ 163,100
Multifamily [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans held		4,494,065						4,494,065		1,862,667
Joint Venture [Member] | Multifamily [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans held		$ 817,900						$ 817,900		$ 484,800

Loans Receivable, Net - Sched_3

Loans Receivable, Net - Schedule Of Current Expected Credit Loss Reserve By Pool (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Loans Receivable, Net
CECL reserve	$ 130,388	$ 128,945	$ 172,100	$ 177,026	$ 178,050	$ 112,694	$ 173,549		$ 0
Increase (decrease) in CECL reserve	98,752	(43,155)	(1,449)	(1,024)	65,356	1,443
U.S. Loans [Member]
Loans Receivable, Net
CECL reserve	20,926	17,673	44,534	50,642	61,404	64,861	42,995
Increase (decrease) in CECL reserve	55,906	(26,861)	1,539	(10,762)	(3,457)	3,253
Non-U.S. Loans [Member]
Loans Receivable, Net
CECL reserve	8,546	8,829	24,600	26,780	19,745	21,825	27,734
Increase (decrease) in CECL reserve	18,194	(15,771)	(3,134)	7,035	(2,080)	(283)
Unique Loans [Member]
Loans Receivable, Net
CECL reserve	31,255	32,782	33,305	29,943	27,240	26,008	33,159		0
Increase (decrease) in CECL reserve	24,652	(523)	146	2,703	1,232	(1,527)
Impaired Loans [Member]
Loans Receivable, Net
CECL reserve	69,661	69,661	69,661	69,661	69,661	0	$ 69,661		$ 0
Increase (decrease) in CECL reserve	$ 0	$ 0	$ 0	$ 0	$ 69,661	$ 0
Accounting Standards Update 2016-13 [Member]
Loans Receivable, Net
CECL reserve								$ 13,942
Accounting Standards Update 2016-13 [Member] | U.S. Loans [Member]
Loans Receivable, Net
CECL reserve								8,955
Accounting Standards Update 2016-13 [Member] | Non-U.S. Loans [Member]
Loans Receivable, Net
CECL reserve								3,631
Accounting Standards Update 2016-13 [Member] | Unique Loans [Member]
Loans Receivable, Net
CECL reserve								1,356
Accounting Standards Update 2016-13 [Member] | Impaired Loans [Member]
Loans Receivable, Net
CECL reserve								$ 0

Loans Receivable, Net - Loans R

Loans Receivable, Net - Loans Receivable Based On Our Internal Risk Ratings, Separated By Year Of Origination (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans receivable	$ 20,406,466			$ 16,572,715
CECL reserve	(130,388)	$ (128,945)	$ (172,100)	(173,549)	$ (177,026)	$ (178,050)	$ (112,694)	$ 0
Loans receivable, net	20,276,078			16,399,166
Loans Receivable [Member]
Financing receivable, originated in current fiscal year	6,693,132			952,873
Financing receivable, originated in fiscal year before latest fiscal year	974,270							6,183,467
Financing receivable, originated two years before latest fiscal year	6,218,224								$ 6,243,324
Financing receivable, originated three years before latest fiscal year	4,682,365									$ 2,093,382
Financing receivable, originated four years before latest fiscal year	1,214,025										$ 543,356
Financing receivable, originated five or more years before latest fiscal year	624,450			556,313
Loans receivable	20,406,466			16,572,715
Loans receivable, net	20,276,078			16,399,166
U.S. Loans [Member]
Financing receivable, originated in current fiscal year	5,673,321			847,573
Financing receivable, originated in fiscal year before latest fiscal year	874,144							3,075,651
Financing receivable, originated two years before latest fiscal year	3,224,700								4,153,881
Financing receivable, originated three years before latest fiscal year	2,951,292									1,998,625
Financing receivable, originated four years before latest fiscal year	1,124,269										429,703
Financing receivable, originated five or more years before latest fiscal year	402,306			443,321
Loans receivable	14,250,032			10,948,754
CECL reserve								0
Non-U.S. Loans [Member]
Financing receivable, originated in current fiscal year	1,019,811			105,300
Financing receivable, originated in fiscal year before latest fiscal year	100,126							2,782,719
Financing receivable, originated two years before latest fiscal year	2,672,368								615,533
Financing receivable, originated three years before latest fiscal year	393,573									94,757
Financing receivable, originated four years before latest fiscal year	89,756										113,653
Financing receivable, originated five or more years before latest fiscal year	110,768			0
Loans receivable	4,386,402			3,711,962
CECL reserve								0
Unique Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							325,097
Financing receivable, originated two years before latest fiscal year	321,156								1,189,101
Financing receivable, originated three years before latest fiscal year	1,052,692									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	58,949			60,604
Loans receivable	1,432,797			1,574,802
CECL reserve	(31,255)	(32,782)	(33,305)	(33,159)	(29,943)	(27,240)	(26,008)	0
Impaired Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								284,809
Financing receivable, originated three years before latest fiscal year	284,808									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	52,427			52,388
Loans receivable	337,235			337,197
CECL reserve	(69,661)	$ (69,661)	$ (69,661)	(69,661)	$ (69,661)	$ (69,661)	$ 0	0
Risk Rating 1 [Member]
Loans receivable	931,330			777,163
Risk Rating 1 [Member] | Loans Receivable [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	43,745							231,796
Financing receivable, originated two years before latest fiscal year	731,641								389,695
Financing receivable, originated three years before latest fiscal year	0									138,663
Financing receivable, originated four years before latest fiscal year	155,944										17,009
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	931,330			777,163
Risk Rating 1 [Member] | U.S. Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	43,745							231,796
Financing receivable, originated two years before latest fiscal year	696,764								253,674
Financing receivable, originated three years before latest fiscal year	0									43,906
Financing receivable, originated four years before latest fiscal year	66,188										17,009
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	806,697			546,385
Risk Rating 1 [Member] | Non-U.S. Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	34,877								136,021
Financing receivable, originated three years before latest fiscal year	0									94,757
Financing receivable, originated four years before latest fiscal year	89,756										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	124,633			230,778
Risk Rating 1 [Member] | Unique Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 1 [Member] | Impaired Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 2 [Member]
Loans receivable	4,800,884			2,513,848
Risk Rating 2 [Member] | Loans Receivable [Member]
Financing receivable, originated in current fiscal year	1,258,391			0
Financing receivable, originated in fiscal year before latest fiscal year	100,126							282,017
Financing receivable, originated two years before latest fiscal year	1,970,668								1,172,168
Financing receivable, originated three years before latest fiscal year	887,935									757,138
Financing receivable, originated four years before latest fiscal year	391,740										79,848
Financing receivable, originated five or more years before latest fiscal year	192,024			222,677
Loans receivable	4,800,884			2,513,848
Risk Rating 2 [Member] | U.S. Loans [Member]
Financing receivable, originated in current fiscal year	694,114			0
Financing receivable, originated in fiscal year before latest fiscal year	0							282,017
Financing receivable, originated two years before latest fiscal year	586,976								1,172,168
Financing receivable, originated three years before latest fiscal year	887,935									757,138
Financing receivable, originated four years before latest fiscal year	391,740										79,848
Financing receivable, originated five or more years before latest fiscal year	81,256			222,677
Loans receivable	2,642,021			2,513,848
Risk Rating 2 [Member] | Non-U.S. Loans [Member]
Financing receivable, originated in current fiscal year	564,277			0
Financing receivable, originated in fiscal year before latest fiscal year	100,126							0
Financing receivable, originated two years before latest fiscal year	1,383,692								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	110,768			0
Loans receivable	2,158,863			0
Risk Rating 2 [Member] | Unique Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 2 [Member] | Impaired Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 3 [Member]
Loans receivable	12,060,623			9,911,914
Risk Rating 3 [Member] | Loans Receivable [Member]
Financing receivable, originated in current fiscal year	5,434,741			886,895
Financing receivable, originated in fiscal year before latest fiscal year	830,399							4,917,522
Financing receivable, originated two years before latest fiscal year	2,752,194								2,350,842
Financing receivable, originated three years before latest fiscal year	2,112,237									1,134,288
Financing receivable, originated four years before latest fiscal year	602,976										341,119
Financing receivable, originated five or more years before latest fiscal year	328,076			281,248
Loans receivable	12,060,623			9,911,914
Risk Rating 3 [Member] | U.S. Loans [Member]
Financing receivable, originated in current fiscal year	4,979,207			781,595
Financing receivable, originated in fiscal year before latest fiscal year	830,399							2,391,297
Financing receivable, originated two years before latest fiscal year	1,844,466								1,672,897
Financing receivable, originated three years before latest fiscal year	1,522,591									1,134,288
Financing receivable, originated four years before latest fiscal year	602,976										227,466
Financing receivable, originated five or more years before latest fiscal year	269,127			220,644
Loans receivable	10,048,766			6,428,187
Risk Rating 3 [Member] | Non-U.S. Loans [Member]
Financing receivable, originated in current fiscal year	455,534			105,300
Financing receivable, originated in fiscal year before latest fiscal year	0							2,526,225
Financing receivable, originated two years before latest fiscal year	907,728								479,512
Financing receivable, originated three years before latest fiscal year	393,573									0
Financing receivable, originated four years before latest fiscal year	0										113,653
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	1,756,835			3,224,690
Risk Rating 3 [Member] | Unique Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								198,433
Financing receivable, originated three years before latest fiscal year	196,073									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	58,949			60,604
Loans receivable	255,022			259,037
Risk Rating 3 [Member] | Impaired Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 4 [Member]
Loans receivable	2,276,394			3,032,593
Risk Rating 4 [Member] | Loans Receivable [Member]
Financing receivable, originated in current fiscal year	0			65,978
Financing receivable, originated in fiscal year before latest fiscal year	0							752,132
Financing receivable, originated two years before latest fiscal year	763,721								2,045,810
Financing receivable, originated three years before latest fiscal year	1,397,385									63,293
Financing receivable, originated four years before latest fiscal year	63,365										105,380
Financing receivable, originated five or more years before latest fiscal year	51,923			0
Loans receivable	2,276,394			3,032,593
Risk Rating 4 [Member] | U.S. Loans [Member]
Financing receivable, originated in current fiscal year	0			65,978
Financing receivable, originated in fiscal year before latest fiscal year	0							170,541
Financing receivable, originated two years before latest fiscal year	96,494								1,055,142
Financing receivable, originated three years before latest fiscal year	540,766									63,293
Financing receivable, originated four years before latest fiscal year	63,365										105,380
Financing receivable, originated five or more years before latest fiscal year	51,923			0
Loans receivable	752,548			1,460,334
Risk Rating 4 [Member] | Non-U.S. Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							256,494
Financing receivable, originated two years before latest fiscal year	346,071								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	346,071			256,494
Risk Rating 4 [Member] | Unique Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							325,097
Financing receivable, originated two years before latest fiscal year	321,156								990,668
Financing receivable, originated three years before latest fiscal year	856,619									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	1,177,775			1,315,765
Risk Rating 4 [Member] | Impaired Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 5 [Member] | Loans Receivable [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								284,809
Financing receivable, originated three years before latest fiscal year	284,808									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	52,427			52,388
Loans receivable	337,235			337,197
Risk Rating 5 [Member] | U.S. Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 5 [Member] | Non-U.S. Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 5 [Member] | Unique Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							0
Financing receivable, originated two years before latest fiscal year	0								0
Financing receivable, originated three years before latest fiscal year	0									0
Financing receivable, originated four years before latest fiscal year	0										0
Financing receivable, originated five or more years before latest fiscal year	0			0
Loans receivable	0			0
Risk Rating 5 [Member] | Impaired Loans [Member]
Financing receivable, originated in current fiscal year	0			0
Financing receivable, originated in fiscal year before latest fiscal year	0							$ 0
Financing receivable, originated two years before latest fiscal year	0								$ 284,809
Financing receivable, originated three years before latest fiscal year	284,808									$ 0
Financing receivable, originated four years before latest fiscal year	0										$ 0
Financing receivable, originated five or more years before latest fiscal year	52,427			52,388
Loans receivable	$ 337,235			$ 337,197

Loans Receivable, Net - Loans_2

Loans Receivable, Net - Loans Receivable Based On Our Internal Risk Ratings, Separated By Year Of Origination (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Held-to-maturity	$ 77,636	$ 75,722
2018 Single Asset Securitization [Member]
Debt Securities, Held-to-maturity	$ 77,600	$ 75,700

Other Assets and Liabilities -

Other Assets and Liabilities - Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Past Due [Line Items]
Accrued interest receivable	$ 78,689			$ 66,757
Debt securities held-to-maturity	77,916			77,445
CECL reserve	(280)	$ (122)	$ (889)	(1,723)	$ (2,033)	$ (4,119)	$ (5,122)	$ 0
Debt securities held-to-maturity, net	77,636			75,722
Derivative assets	35,858			522
2021 FL4 CLO restricted cash	25,000			0	$ 0
Loan portfolio payments held by servicer	766			73,224
Prepaid expenses	43			973
Collateral deposited under derivative agreements	0			51,050
Prepaid taxes	0			376
Other	622			1,195
Total	$ 218,614			$ 269,819

Other Assets and Liabilities _2

Other Assets and Liabilities - Summary of Components of Other Assets (Parenthetical) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Schedule Of Other Assets [Line Items]
Percentage of yield in subordinate risk retention interest	10.00%
Restricted cash	$ 25,000	$ 0	$ 0
2021 FL4 CLO [Member]
Schedule Of Other Assets [Line Items]
Restricted cash	25,000
2018 Single Asset Securitization [Member]
Schedule Of Other Assets [Line Items]
Single asset securitization principal amount	$ 493,300	$ 735,500
Single asset securitization maximum maturity date	Jun. 9, 2025

Other Assets and Liabilities _3

Other Assets and Liabilities - Summary Of Current Expected Credit Loss Reserve By Pool (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Current Expected Credit Loss Reserve	$ 122	$ 889	$ 1,723	$ 4,119	$ 5,122	$ 0	$ 1,723	$ 0
Increase (Decrease) in current expected credit loss reserve	158	(767)	(834)	(2,086)	(1,003)	4,677
Current Expected Credit Loss Reserve	$ 280	$ 122	$ 889	$ 2,033	$ 4,119	5,122	$ 280	2,033
Accounting Standards Update 2016-13 [Member]
Current Expected Credit Loss Reserve						$ 445		$ 445

Other Assets and Liabilities _4

Other Assets and Liabilities - Additional Information (Detail) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021USD ($)Loans	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)Loans	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
CECL reserve	$ 130,388	$ 128,945	$ 172,100	$ 177,026	$ 178,050	$ 112,694	$ 130,388	$ 177,026	$ 173,549		$ 0
Increase (Decrease) in current expected credit loss reserve	158	(767)	(834)	(2,086)	(1,003)	4,677
Current expected credit loss reserve	$ 280	122	889	2,033	4,119	5,122	$ 280	2,033	1,723		0
Number of loans receivable | Loans	108						108
Credit Loss Reserve [Member]
CECL reserve	$ 280,000			2,000			$ 280,000	2,000
Increase (Decrease) in current expected credit loss reserve	(158,000)			(2,100)			(1,400)	1,600
Unfunded Loan Commitments [Member]
CECL reserve	5,203	$ 4,037	$ 11,021	12,057	$ 15,002	$ 22,536	5,203	12,057	$ 10,031		0
Increase (Decrease) in current expected credit loss reserve	$ (1,200)			$ (2,900)			$ (4,800)	8,800
Number of loans receivable | Loans	108						108
Unfunded loan commitments	$ 4,200,000						$ 4,200,000
Accounting Standards Update 2016-13 [Member]
CECL reserve										$ 13,942
Current expected credit loss reserve										445,000	$ 445
Accounting Standards Update 2016-13 [Member] | Unfunded Loan Commitments [Member]
CECL reserve	$ 3,300						3,300			$ 3,263
Increase (Decrease) in current expected credit loss reserve							$ 5,200	$ 12,100

Other Assets and Liabilities _5

Other Assets and Liabilities - Summary of Components of Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Accrued dividends payable	$ 97,350			$ 91,004
Accrued interest payable	25,772			20,548
Accrued management and incentive fees payable	19,342			19,158
Accounts payable and other liabilities	11,080			2,671
Current expected credit loss reserve for unfunded loan commitments	130,388	$ 128,945	$ 172,100	173,549	$ 177,026	$ 178,050	$ 112,694	$ 0
Derivative liabilities	355			58,915
Secured debt repayments pending servicer remittance	322			0
Total	159,424			202,327
Unfunded Loan Commitments [Member]
Current expected credit loss reserve for unfunded loan commitments	$ 5,203	$ 4,037	$ 11,021	$ 10,031	$ 12,057	$ 15,002	$ 22,536	$ 0

Other Assets and Liabilities _6

Other Assets and Liabilities - Summary of Unfunded Loan Commitment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
CECL reserve	$ 130,388	$ 128,945	$ 172,100	$ 177,026	$ 178,050	$ 112,694	$ 173,549		$ 0
(Decrease) Increase in CECL reserve	98,752	(43,155)	(1,449)	(1,024)	65,356	1,443
U.S. Loans [Member]
CECL reserve	20,926	17,673	44,534	50,642	61,404	64,861	42,995
(Decrease) Increase in CECL reserve	55,906	(26,861)	1,539	(10,762)	(3,457)	3,253
Non-U.S. Loans [Member]
CECL reserve	8,546	8,829	24,600	26,780	19,745	21,825	27,734
(Decrease) Increase in CECL reserve	18,194	(15,771)	(3,134)	7,035	(2,080)	(283)
Unfunded Loan Commitment [Member]
CECL reserve	5,203	4,037	11,021	12,057	15,002	22,536	10,031		0
(Decrease) Increase in CECL reserve	1,166	(6,984)	990	(2,945)	(7,534)	19,273
Unfunded Loan Commitment [Member] | U.S. Loans [Member]
CECL reserve	3,420	2,854	7,169	9,179	12,836	19,793	6,953		0
(Decrease) Increase in CECL reserve	566	(4,315)	216	(3,657)	(6,957)	16,992
Unfunded Loan Commitment [Member] | Non-U.S. Loans [Member]
CECL reserve	1,783	1,140	3,772	2,810	2,078	2,672	2,994		0
(Decrease) Increase in CECL reserve	643	(2,632)	778	732	(594)	2,219
Accounting Standards Update 2016-13 [Member]
CECL reserve								$ 13,942
Accounting Standards Update 2016-13 [Member] | U.S. Loans [Member]
CECL reserve								8,955
Accounting Standards Update 2016-13 [Member] | Non-U.S. Loans [Member]
CECL reserve								3,631
Accounting Standards Update 2016-13 [Member] | Unfunded Loan Commitment [Member]
CECL reserve	3,300							3,263
Accounting Standards Update 2016-13 [Member] | Unfunded Loan Commitment [Member] | U.S. Loans [Member]
CECL reserve								2,801
Accounting Standards Update 2016-13 [Member] | Unfunded Loan Commitment [Member] | Non-U.S. Loans [Member]
CECL reserve								453
Unique Loans [Member]
CECL reserve	31,255	32,782	33,305	29,943	27,240	26,008	33,159		0
(Decrease) Increase in CECL reserve	24,652	(523)	146	2,703	1,232	(1,527)
Unique Loans [Member] | Unfunded Loan Commitment [Member]
CECL reserve	0	43	80	68	88	71	84		0
(Decrease) Increase in CECL reserve	(43)	(37)	(4)	(20)	17	62
Unique Loans [Member] | Accounting Standards Update 2016-13 [Member]
CECL reserve								1,356
Unique Loans [Member] | Accounting Standards Update 2016-13 [Member] | Unfunded Loan Commitment [Member]
CECL reserve								9
Impaired Loans [Member]
CECL reserve	69,661	69,661	69,661	69,661	69,661	0	69,661		0
(Decrease) Increase in CECL reserve	0	0	0	0	69,661	0
Impaired Loans [Member] | Unfunded Loan Commitment [Member]
CECL reserve	0	0	0	0	0	0	$ 0		$ 0
(Decrease) Increase in CECL reserve	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Impaired Loans [Member] | Accounting Standards Update 2016-13 [Member]
CECL reserve								0
Impaired Loans [Member] | Accounting Standards Update 2016-13 [Member] | Unfunded Loan Commitment [Member]
CECL reserve								$ 0

Secured Debt, Net - Additional

Secured Debt, Net - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Debt Instrument [Line Items]
Interest expense	$ 82,690,000	$ 78,978,000	$ 243,413,000		$ 268,070,000
Covenants, minimum tangible net worth	$ 3,200,000,000		$ 3,200,000,000
Covenants, percentage of tangible assets on cash proceeds from equity issuances			75.00%
Covenants, percentage of recourse indebtedness	5.00%		5.00%
Maximum [Member]
Debt Instrument [Line Items]
Covenants, indebtedness to total assets, in percent	83.33%		83.33%
Minimum [Member]
Debt Instrument [Line Items]
Covenants, EBITDA to fixed charges, in percent			1.40%
Covenants, minimum cash liquidity amount	$ 10,000,000		$ 10,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Interest expense			925,000	$ 1,100,000
Amortization of deferred fees and expenses			262,000	411,000
Revolving Credit Facility [Member] | Acquisition Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity	146,300,000		146,300,000
Revolving Credit Facility [Member] | Barclays [Member]
Debt Instrument [Line Items]
Maximum Facility Size	250,000,000		250,000,000
Credit Facilities [Member]
Debt Instrument [Line Items]
Collateral Assets	15,258,991,000		15,258,991,000	$ 12,040,907,000
Line of credit facility, remaining borrowing capacity	306,200,000,000		306,200,000,000
Credit Facilities Six [Member]
Debt Instrument [Line Items]
Potential	2,800,000,000		2,800,000,000
Collateral Assets	3,500,000,000		3,500,000,000
Credit Facilities Eight [Member] | One of the Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Additional credit capacity	150,000,000
Credit Facilities Eight [Member] | Four of the Eight Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Maximum Facility Size	$ 2,300,000,000		$ 2,300,000,000

Secured Debt, Net - Schedule of

Secured Debt, Net - Schedule of Secured Debt Agreements (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	$ 11,188,855	$ 7,896,863
Deferred financing costs	(18,525)	(16,327)
Net book value of secured debt	11,170,330	7,880,536
Secured Debt [Member]
Debt Instrument [Line Items]
Secured debt agreements borrowings outstanding	11,188,855	7,896,863
Acquisition Facility [Member]
Debt Instrument [Line Items]
Secured debt repurchase agreement acquisition facility face amount	$ 0	$ 0

Secured Debt, Net - Schedule _2

Secured Debt, Net - Schedule of Secured Credit Facilities (Detail) - Secured Debt [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)Countries
Schedule Of Secured Credit Facilities [Line Items]
Lenders | Countries	12
Borrowings | $	$ 11,188,855
Wtd Avg. Maturity	Feb. 17, 2025
Loan Count | Countries	141
Collateral | $	$ 15,258,991
Wtd Avg. Maturity	Feb. 10, 2025
Recourse Limitation Wtd. Avg.	32.00%
Minimum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	25.00%
Maximum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	100.00%
USD [Member]
Schedule Of Secured Credit Facilities [Line Items]
Lenders | Countries	12
Borrowings | $	$ 7,022,125
Wtd Avg. Maturity	May 5, 2025
Loan Count | Countries	114
Collateral | $	$ 9,557,168
Wtd Avg. Maturity	May 1, 2025
Recourse Limitation Wtd. Avg.	29.00%
USD [Member] | Minimum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	25.00%
USD [Member] | Maximum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	100.00%
EUR [Member]
Schedule Of Secured Credit Facilities [Line Items]
Lenders | Countries	6
Borrowings | $	$ 2,369,013
Wtd Avg. Maturity	Jul. 26, 2024
Loan Count | Countries	10
Collateral | $	$ 3,150,165
Wtd Avg. Maturity	Jul. 4, 2024
Recourse Limitation Wtd. Avg.	48.00%
EUR [Member] | Minimum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	25.00%
EUR [Member] | Maximum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	100.00%
GBP [Member]
Schedule Of Secured Credit Facilities [Line Items]
Lenders | Countries	6
Borrowings | $	$ 1,163,414
Wtd Avg. Maturity	Oct. 22, 2024
Loan Count | Countries	12
Collateral | $	$ 1,739,121
Wtd Avg. Maturity	Nov. 9, 2024
Recourse Limitation Wtd. Avg.	26.00%
GBP [Member] | Minimum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	25.00%
GBP [Member] | Maximum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	50.00%
Other Currencies [Member]
Schedule Of Secured Credit Facilities [Line Items]
Lenders | Countries	4
Borrowings | $	$ 634,303
Wtd Avg. Maturity	Jun. 17, 2025
Loan Count | Countries	5
Collateral | $	$ 812,537
Wtd Avg. Maturity	May 28, 2025
Recourse Limitation Wtd. Avg.	27.00%
Other Currencies [Member] | Minimum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	25.00%
Other Currencies [Member] | Maximum [Member]
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range	100.00%

Secured Debt, Net - Schedule _3

Secured Debt, Net - Schedule of All in Cost of Secured Credit Facilities (Detail) - Credit Facilities [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 5,279,550	$ 898,516
Total Borrowings	$ 11,188,855	$ 7,896,863
Wtd. Avg. All-in Cost	1.77%	1.83%
Collateral	$ 15,258,991	$ 12,040,907
Wtd. Avg. All-in Yield	3.41%	3.40%
Net Interest Margin	1.64%	1.57%
1.50% or less [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 3,065,115	$ 376,085
Total Borrowings	$ 6,288,807	$ 4,192,280
Wtd. Avg. All-in Cost	1.54%	1.59%
Collateral	$ 8,176,251	$ 6,338,626
Wtd. Avg. All-in Yield	3.09%	3.09%
Net Interest Margin	1.55%	1.50%
1.51% to + 1.75% [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 1,268,796	$ 172,447
Total Borrowings	$ 2,780,867	$ 1,945,692
Wtd. Avg. All-in Cost	1.88%	1.95%
Collateral	$ 3,851,597	$ 2,975,581
Wtd. Avg. All-in Yield	3.40%	3.43%
Net Interest Margin	1.52%	1.48%
1.76% to + 2.00% [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 479,767	$ 215,056
Total Borrowings	$ 897,258	$ 926,666
Wtd. Avg. All-in Cost	2.08%	2.06%
Collateral	$ 1,253,906	$ 1,212,546
Wtd. Avg. All-in Yield	3.95%	3.83%
Net Interest Margin	1.87%	1.77%
2.01% or more [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
New Financings	$ 465,872	$ 134,928
Total Borrowings	$ 1,221,923	$ 832,225
Wtd. Avg. All-in Cost	2.42%	2.49%
Collateral	$ 1,977,237	$ 1,514,154
Wtd. Avg. All-in Yield	4.42%	4.34%
Net Interest Margin	2.00%	1.85%

Secured Debt, Net - Schedule _4

Secured Debt, Net - Schedule of All in Cost of Secured Credit Facilities (Parenthetical) (Detail) - Credit Facilities [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
USD LIBOR Rate [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
Basis spread on debt obligation, in percent	1.50%	1.50%
GBP LIBOR [Member] | Maximum [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
Basis spread on debt obligation, in percent	1.75%	1.75%
GBP LIBOR [Member] | Minimum [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
Basis spread on debt obligation, in percent	1.51%	1.51%
Sterling Overnight Interbank Average Rate [Member] | Maximum [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
Basis spread on debt obligation, in percent	2.00%	2.00%
Sterling Overnight Interbank Average Rate [Member] | Minimum [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
Basis spread on debt obligation, in percent	1.76%	1.76%
Sek [Member]
Schedule Of All In Cost Of Secured Credit Facilities [Line Items]
Basis spread on debt obligation, in percent	2.01%	2.01%

Securitized Debt Obligations,_3

Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Detail) $ in Thousands		9 Months Ended		12 Months Ended
		Sep. 30, 2021USD ($)Loans		Dec. 31, 2020USD ($)Loans
Financing Provided [Member]
Debt Instrument [Line Items]
Count | Loans		3	[1]	4	[2]
Principal Balance		$ 2,855,625	[1]	$ 2,940,638	[2]
Book Value		$ 2,836,049	[1]	$ 2,922,499	[2]
Financing Provided [Member] | 2021 FL4 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans		1
Principal Balance		$ 803,750
Book Value		$ 796,864
Financing Provided [Member] | 2020 FL3 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans		1	[3]	1
Principal Balance		$ 808,750	[3]	$ 808,750
Book Value		$ 803,378	[3]	$ 800,993
Financing Provided [Member] | 2020 FL2 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans		1	[3]	1
Principal Balance		$ 1,243,125	[3]	$ 1,243,125
Book Value		$ 1,235,807	[3]	$ 1,233,464
Financing Provided [Member] | 2017 FL1 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans				1
Principal Balance				$ 483,834
Book Value				$ 483,113
Financing Provided [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Count | Loans				1
Principal Balance				$ 404,929
Book Value				$ 404,929
Collateral Assets [Member]
Debt Instrument [Line Items]
Count | Loans		80		72
Principal Balance		$ 3,500,000		$ 3,785,528
Book Value		$ 3,500,000		$ 3,785,100
Collateral Assets [Member] | 2021 FL4 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans		35
Principal Balance		$ 1,000,000
Book Value		$ 1,000,000
Collateral Assets [Member] | 2020 FL3 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans		21		25
Principal Balance		$ 1,000,000		$ 1,000,000
Book Value		$ 1,000,000		$ 1,000,000
Collateral Assets [Member] | 2020 FL2 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans		24		31
Principal Balance		$ 1,500,000		$ 1,500,000
Book Value		$ 1,500,000		$ 1,500,000
Collateral Assets [Member] | 2017 FL1 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Count | Loans				15
Principal Balance				$ 666,334
Book Value				$ 666,334
Collateral Assets [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Count | Loans	[4]			1
Principal Balance	[4]			$ 619,194
Book Value	[4]			$ 618,766
LIBOR [Member] | Financing Provided [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5]	1.69%	[1],[3]	1.70%	[2],[6]
LIBOR [Member] | Financing Provided [Member] | 2021 FL4 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[3],[5]	1.65%
Term	[7]	2038-05
LIBOR [Member] | Financing Provided [Member] | 2020 FL3 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5]	2.10%	[3]	2.08%	[6]
Term	[7]			2037-11
LIBOR [Member] | Financing Provided [Member] | 2020 FL2 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5]	1.45%	[3]	1.44%	[6]
Term	[7]			2038-02
LIBOR [Member] | Financing Provided [Member] | 2017 FL1 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5],[6]			1.83%
Term	[7]			2035-06
LIBOR [Member] | Financing Provided [Member] | 2020 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5],[6]			1.63%
LIBOR [Member] | Financing Provided [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Term	[7]			2033-06
LIBOR [Member] | Collateral Assets [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5]	3.17%	[3]	3.25%	[6]
LIBOR [Member] | Collateral Assets [Member] | 2021 FL4 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[3],[5]	3.41%
Term	[7]	2024-07
LIBOR [Member] | Collateral Assets [Member] | 2020 FL3 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5]	3.02%	[3]	3.09%	[6]
Term	[7]	2024-04		2024-02
LIBOR [Member] | Collateral Assets [Member] | 2020 FL2 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5]	3.10%	[3]	3.17%	[6]
Term	[7]	2024-03		2024-01
LIBOR [Member] | Collateral Assets [Member] | 2017 FL1 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[5],[6]			3.39%
Term	[7]			2023-01
LIBOR [Member] | Collateral Assets [Member] | 2020 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[4],[5],[6]			3.57%
LIBOR [Member] | Collateral Assets [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Term	[4],[7]			2023-06
SOFR [Member] | Financing Provided [Member] | 2020 FL3 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Term	[3],[7]	2037-11
SOFR [Member] | Financing Provided [Member] | 2020 FL2 Collateralized Loan Obligation [Member]
Debt Instrument [Line Items]
Term	[3],[7]	2038-02
[1]	During the three and nine months ended September 30, 2021, we recorded $10.7 million and $35.2 million, respectively, of interest expense related to our securitized debt obligations.
[2]	During the three and nine months ended September 30, 2020, we recorded $9.1 million and $31.8 million, respectively, of interest expense related to our securitized debt obligations.
[3]	The weighted-average all-in yield and cost are expressed as a spread over the relevant floating benchmark rates, which include USD LIBOR and SOFR, as applicable to each securitized debt obligation. As of September 30, 2021, the floating benchmark rate for the financing provided on the 2020 FL3 and 2020 FL2 CLOs is the 30-day average compounded SOFR, plus a credit spread adjustment of 0.11%. As of September 30, 2021, the 30-day average compounded SOFR was 0.05% and one-month USD LIBOR was 0.08%.
[4]	The collateral assets for the 2017 Single Asset Securitization include the total loan amount, of which we securitized $500.0 million.
[5]	In addition to cash coupon, all-in yield includes the amortization of deferred origination and extension fees, loan origination costs, purchase discounts, and accrual of exit fees.
[6]	The weighted-average all-in yield and cost are expressed as a spread over USD LIBOR.
[7]	Loan term represents weighted-average final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitizations.

Securitized Debt Obligations,_4

Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Interest expense on securitized debt obligations	$ 10.7	$ 9.1	$ 35.2	$ 31.8
Credit spread adjustment	0.11%		0.11%
LIBOR [Member]
Debt Instrument [Line Items]
One-month USD LIBOR	0.08%		0.08%
SOFR [Member]
Debt Instrument [Line Items]
30-day average compounded SOFR	0.05%		0.05%
Collateral Assets [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Total loan amount, securitized					$ 500

Asset-Specific Debt, Net - Summ

Asset-Specific Debt, Net - Summary of Asset-Specific Financings (Detail) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)SecurityLoan	Dec. 31, 2020USD ($)SecurityLoan
Participating Mortgage Loans [Line Items]
Financing provided, Principal Balance	$ 11,188,855	$ 7,896,863
Asset Specific Financings [Member]
Participating Mortgage Loans [Line Items]
Count | SecurityLoan	3	4
Financing provided, Principal Balance	$ 328,068	$ 399,699
Financing provided	2024-12	2023-10
Financing provided, Book Value	$ 320,895	$ 391,269
LIBOR [Member] | Asset Specific Financings [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost Rate	3.13%	3.48%
Collateral Assets [Member]
Participating Mortgage Loans [Line Items]
Count | SecurityLoan	3	4
Collateral assets, Book Value	$ 424,650	$ 499,085
Financing provided	2024-12	2023-10
Collateral assets, Principal Balance	$ 436,562	$ 512,794
Collateral Assets [Member] | LIBOR [Member]
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost Rate	4.34%	4.65%

Term Loans, Net - Additional In

Term Loans, Net - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Secured term loan percentage of partially amortizing	1.00%
Secured term loan covenant description	The guarantee under our Term Loans contains the financial covenant that our indebtedness shall not exceed 83.33% of our total assets.
B-1 Term Loan
Secured term loan percentage of partially amortizing	1.00%
Discount upon issuance of Secured term loan	$ 3.1
Secured term loan transaction expenses	12.6
Secured term loan facility face value	$ 200
B-1 Term Loan | LIBOR [Member]
Basis spread on debt obligation, in percent	2.75%
B-2 Term Loan
Secured term loan percentage of partially amortizing	1.00%
Discount upon issuance of Secured term loan	$ 9.6
Secured term loan transaction expenses	5.4
Secured term loan facility face value	$ 100
Basis spread on debt obligation, in percent	0.50%
B-2 Term Loan | LIBOR [Member]
Basis spread on debt obligation, in percent	2.50%

Term Loans, Net - Schedule of D

Term Loans, Net - Schedule of Debt (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
B-1 Term Loan
Face Value	$ 932,256
Interest rate	2.25
All-in Cost	2.53
Maturity	Apr. 23, 2026
B-2 Term Loan
Face Value	$ 420,450
Interest rate	2.75
All-in Cost	3.42
Maturity	Apr. 23, 2026

Term Loans, Net - Schedule of_2

Term Loans, Net - Schedule of Debt (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2021
B-2 Term Loan
Debt Instrument [Line Items]
Basis spread on debt obligation, in percent	0.50%

Term Loans, Net - Schedule of N

Term Loans, Net - Schedule of Net Book Value of Our Term Loans on Our Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Deferred financing costs	$ (18,525)	$ (16,327)
Term Loan
Face value	1,352,706	1,062,766
Unamortized discount	(9,748)	(9,807)
Deferred financing costs	(13,321)	(11,255)
Net book value	$ 1,329,637	$ 1,041,704

Convertible Notes, Net - Summar

Convertible Notes, Net - Summary of Outstanding Convertible Senior Notes (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
4.38% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Note Issuance	2017-05
Face Value	$ 402,500
Interest Rate	4.38%
All-in Cost	4.85%
Conversion Rate	28.0324
Maturity	May 5, 2022
4.75% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Note Issuance	2018-03
Face Value	$ 220,000
Interest Rate	4.75%
All-in Cost	5.33%
Conversion Rate	27.6052
Maturity	Mar. 15, 2023

Convertible Notes, Net - Summ_2

Convertible Notes, Net - Summary of Outstanding Convertible Senior Notes (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2021USD ($)$ / shares
Debt Instrument [Line Items]
Convertible Notes, debt conversion, principal amount | $	$ 1,000
4.38% Convertible Senior Notes [Member] | Class A Common Stock [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, principal amount | $	$ 1,000
Debt instrument, conversion price	$ 0
4.75% Convertible Senior Notes Issued In March 2018 [Member] | Class A Common Stock [Member]
Debt Instrument [Line Items]
Debt instrument, conversion price	35.67
Debt instrument, conversion price	0
4.38% Convertible Senior Notes Issued in May 2017 [Member] | Class A Common Stock [Member]
Debt Instrument [Line Items]
Debt instrument, conversion price	36.23
Debt instrument, conversion price	$ 0

Convertible Notes, Net - Additi

Convertible Notes, Net - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Mar. 31, 2018	May 31, 2017
Debt Instrument [Line Items]
Accrued interest payable	$ 25,772,000	$ 20,548,000
5.25% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Description of Convertible Notes conversion	The Convertible Notes are convertible at the holders’ option into shares of our class A common stock, only under specific circumstances, prior to the close of business on January 31, 2022 and December 14, 2022 for the May 2017 and March 2018 convertible notes, respectively, at the applicable conversion rate in effect on the conversion date.
Discount upon issuance of Convertible Notes			$ 1,500,000
Debt issuance costs			$ 5,200,000
Convertible Notes, assumed effective interest rate			5.25%
Convertible Senior Notes, Interest rate including amortization of discount upon issuance			5.49%
Accrued interest payable	$ 7,800,000	$ 6,000,000
4.38% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Discount upon issuance of Convertible Notes				$ 979,000
Debt issuance costs				$ 8,400,000
Convertible Notes, assumed effective interest rate				4.57%
Convertible Senior Notes, Interest rate including amortization of discount upon issuance				4.91%

Convertible Notes, Net - Summ_3

Convertible Notes, Net - Summary of Details of Net Book Value of Convertible Note (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Deferred financing costs	$ (18,525)	$ (16,327)
Net book value	618,985	616,389
Convertible Senior Note [Member]
Debt Instrument [Line Items]
Face Value	622,500	622,500
Unamortized discount	(3,301)	(5,715)
Deferred financing costs	(214)	(396)
Net book value	$ 618,985	$ 616,389

Convertible Notes, Net - Summ_4

Convertible Notes, Net - Summary of Details about Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Discount and issuance cost amortization			$ 29,698	$ 28,122
Convertible Senior Note [Member]
Debt Instrument [Line Items]
Cash coupon	$ 7,015	$ 7,015	21,045	21,045
Discount and issuance cost amortization	873	831	2,595	2,470
Total interest expense	$ 7,888	$ 7,846	$ 23,640	$ 23,515

Derivative Financial Instrume_3

Derivative Financial Instruments - Summary of Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk (Detail) - Cash Flow Hedges [Member] - Designated as Hedging Instrument [Member] - Interest Rate Caps [Member] - CAD [Member] - CDOR [Member] $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021CAD ($)DerivativeInstrument	Dec. 31, 2020CAD ($)DerivativeInstrument
Derivative [Line Items]
Number of Instruments | DerivativeInstrument	1	2
Notional Amount | $	$ 21,020	$ 38,293
Strike	1.00%	1.00%
Wtd. Avg. Maturity (Years)	2 months 12 days	9 months 18 days

Derivative Financial Instrume_4

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of collateral posted for the net assets/liability positions	$ 0	$ 51,050,000
Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification from accumulated other comprehensive income (loss) as increase to interest income	$ 3,000

Derivative Financial Instrume_5

Derivative Financial Instruments - Summary of Outstanding Foreign Exchange Derivatives Designated as Net Investment Hedges of Foreign Currency Risk (Detail) - Designated as Hedging Instrument [Member] - Net Investment Hedges [Member] € in Thousands, £ in Thousands, kr in Thousands, $ in Thousands, $ in Thousands	Sep. 30, 2021CAD ($)DerivativeInstrument	Sep. 30, 2021SEK (kr)DerivativeInstrument	Sep. 30, 2021EUR (€)DerivativeInstrument	Sep. 30, 2021GBP (£)DerivativeInstrument	Sep. 30, 2021AUD ($)DerivativeInstrument	Dec. 31, 2020CAD ($)DerivativeInstrument	Dec. 31, 2020EUR (€)DerivativeInstrument	Dec. 31, 2020GBP (£)DerivativeInstrument	Dec. 31, 2020AUD ($)DerivativeInstrument
Buy USD / Sell SEK Forward [Member] | SEK [Member]
Derivative [Line Items]
Number of Instruments	1	1	1	1	1
Notional Amount | kr		kr 999,500
Buy USD / Sell EUR Forward [Member] | EUR [Member]
Derivative [Line Items]
Number of Instruments	6	6	6	6	6	8	8	8	8
Notional Amount | €			€ 817,642				€ 754,722
Buy USD / Sell GBP Forward [Member] | GBP [Member]
Derivative [Line Items]
Number of Instruments	1	1	1	1	1	4	4	4	4
Notional Amount | £				£ 542,551				£ 372,487
Buy USD / Sell AUD Forward [Member] | AUD [Member]
Derivative [Line Items]
Number of Instruments	1	1	1	1	1	1	1	1	1
Notional Amount | $					$ 89,500				$ 92,800
Buy USD / Sell CAD Forward [Member] | CAD [Member]
Derivative [Line Items]
Number of Instruments	1	1	1	1	1	1	1	1	1
Notional Amount | $	$ 21,000					$ 26,200

Derivative Financial Instrume_6

Derivative Financial Instruments - Summary of Non-designated Hedges (Detail) - Not Designated as Hedging Instrument [Member] € in Thousands, £ in Thousands	Sep. 30, 2021EUR (€)DerivativeInstrument	Sep. 30, 2021GBP (£)DerivativeInstrument	Dec. 31, 2020EUR (€)DerivativeInstrument	Dec. 31, 2020GBP (£)DerivativeInstrument
GBP [Member] | Buy EUR / Sell GBP Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments			2	2
Notional Amount | £				£ 146,207
EUR [Member] | Buy USD / Sell EUR Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | €	€ 13,900		€ 8,410
EUR [Member] | Buy GBP / Sell EUR Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1
Notional Amount | £		£ 8,410
USD [Member] | Buy EUR / Sell USD Forward [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of Instruments	1	1
Notional Amount | €	€ 13,900

Derivative Financial Instrume_7

Derivative Financial Instruments - Schedule of Derivative Instruments Gain Loss in Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net			$ 3,298	$ 754
Foreign Exchange Forward [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 1,568	$ 2,236	(2,185)	1,235
Designated as Hedging Instrument [Member] | Interest Income [Member] | Foreign Exchange Forward [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	1,542	1,794	5,294	2,303
Not Designated as Hedging Instrument [Member] | Interest Income [Member] | Foreign Exchange Forward [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	34	(227)	(340)	(222)
Not Designated as Hedging Instrument [Member] | Interest Expense [Member] | Foreign Exchange Forward [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ (8)	$ 669	$ (7,139)	$ (846)

Derivative Financial Instrume_8

Derivative Financial Instruments - Summary of Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	$ 35,858	$ 522
Fair Value of Derivatives in a Liability Position	355	58,915
Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	35,460	522
Fair Value of Derivatives in a Liability Position	0	55,758
Designated as Hedging Instrument [Member] | Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	0	1
Fair Value of Derivatives in a Liability Position	0	0
Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	35,460	521
Fair Value of Derivatives in a Liability Position	0	55,758
Not Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	398	0
Fair Value of Derivatives in a Liability Position	355	3,157
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	0	0
Fair Value of Derivatives in a Liability Position	0	0
Not Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives in an Asset Position	398	0
Fair Value of Derivatives in a Liability Position	$ 355	$ 3,157

Derivative Financial Instrume_9

Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	$ 46,078,000	$ 65,052,000
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	(5,000)	(7,000)
Net Investment [Member] | Foreign Currency Contracts [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	46,078,000	65,052,000
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	0	0
Cash Flow Hedges [Member] | Interest Rate Swaps/Derivatives [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	0	0
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	$ (5,000)	$ (7,000)

Derivative Financial Instrum_10

Derivative Financial Instruments - Summary of Effect of Derivative Financial Instruments on Consolidated Statements of Operations (Parenthetical) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest and related expenses	$ 82,690,000	$ 78,978,000	$ 243,413,000	$ 268,070,000
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	5,000		7,000
Interest Rate Swaps/Derivatives [Member] | Cash Flow Hedges [Member] | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	5,000		7,000
Foreign Currency Contracts [Member] | Net Investment Hedges [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net cash settlements on our foreign currency forward contracts	$ 18,300,000		$ 31,000,000

Equity - Additional Information

Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 14, 2018	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Mar. 25, 2014
Class of Stock [Line Items]
Total stock, shares authorized		500,000,000		500,000,000
Common stock, shares authorized		400,000,000		400,000,000		400,000,000
Dividends paid				$ 97,300
Dividends paid per common stock				$ 0.62
Date of dividend paid				Oct. 15, 2021
Date of dividend declared				Sep. 15, 2021
Record date of dividend paid				Sep. 30, 2021
Accumulated other comprehensive income (loss)		$ 9,874		$ 9,874		$ 11,170
Net realized and unrealized gains related to changes in fair value of derivative instruments		69,900		69,900		4,800
Cumulative unrealized currency translation adjustment on assets and liabilities denominated in foreign currencies		60,000		60,000		6,400
Multifamily [Member] | Joint Venture [Member]
Class of Stock [Line Items]
Total equity		226,700		226,700		121,100
Equity interests owned by Blackstone Mortgage Trust, Inc.		192,700		192,700		102,900
Non-controlling interests		$ 34,000		$ 34,000		$ 18,200
Dividend Reinvestment and Direct Stock Purchase Plan [Member]
Class of Stock [Line Items]
Reserved for issuance of class A common stock		9,990,545		9,990,545			10,000,000
Class A Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized		400,000,000		400,000,000
Preferred stock, shares authorized		100,000,000		100,000,000
Common stock, shares issued under dividend reinvestment program				1,429	1,599
Class A Common Stock [Member] | Dividend Reinvestment and Direct Stock Purchase Plan [Member]
Class of Stock [Line Items]
Common stock, shares issued under dividend reinvestment program		480	628	1,429	1,599
Class A Common Stock [Member] | ATM Agreements [Member]
Class of Stock [Line Items]
Aggregate sales price	$ 500,000
Aggregate sales price remaining available		$ 363,800		$ 363,800

Equity - Summary of Class A Com

Equity - Summary of Class A Common Stock Issuances (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	9 Months Ended
		May 31, 2013	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Shares issued		25,875,000	10,001,429	10,842,295
Net proceeds			$ 311,955	$ 278,322
Class A Common Stock [Member]
Class of Stock [Line Items]
Shares issued			10,000,000
Gross per share issue price			$ 31.45
Net per share issue price			$ 31.24
Net proceeds	[1]		$ 311,955
[1]	Net proceeds represents proceeds received from the underwriters less applicable transaction costs.

Equity - Schedule of Movement i

Equity - Schedule of Movement in Outstanding Shares of Class A Common Stock, Restricted Class A Common Stock and Deferred Stock Units (Detail) - shares		1 Months Ended	9 Months Ended
		May 31, 2013	Sep. 30, 2021	Sep. 30, 2020
Equity [Abstract]
Beginning balance			147,086,722	135,263,728
Issuance of class A common stock		25,875,000	10,001,429	10,842,295
Issuance of restricted class A common stock, net	[1]		234,229	351,333
Issuance of deferred stock units			50,009	33,790
Ending balance			157,372,389	146,491,146
[1]	The amounts are net of 29,580 and 249 shares of restricted class A common stock forfeited under our stock-based incentive plans during the nine months ended September 30, 2021 and 2020, respectively. See Note 14 for further discussion of our stock-based incentive plans.

Equity - Schedule of Movement_2

Equity - Schedule of Movement in Outstanding Shares of Class A Common Stock, Restricted Class A Common Stock and Deferred Stock Units (Parenthetical) (Detail) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Class A Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares issued under dividend reinvestment program	1,429	1,599
Restricted Stock [Member]
Class of Stock [Line Items]
Deferred stock units held by directors	356,700	293,856
Restricted Class A Common Stock, Forfeited	29,580
Restricted Stock [Member] | Class A Common Stock [Member]
Class of Stock [Line Items]
Restricted Class A Common Stock, Forfeited	29,580	249

Equity - Schedule of Dividend A

Equity - Schedule of Dividend Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Equity [Abstract]
Dividends declared per share of common stock	$ 0.62	$ 0.62	$ 0.62	$ 0.62	$ 0.62	$ 0.62	$ 1.86	$ 1.86
Class A common stock dividends declared	$ 97,350			$ 90,642			$ 279,659	$ 265,205
Deferred stock unit dividends declared	202			174			591	502
Total dividends declared	$ 97,552			$ 90,816			$ 280,250	$ 265,707

Equity - Schedule of Basic and

Equity - Schedule of Basic and Diluted Earnings Per Share, or EPS, Based on Weighted-Average of Both Restricted and Unrestricted Class A Common Stock Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income (loss)	$ 83,757	$ 89,860	$ 295,254	$ 54,054
Weighted-average shares outstanding, basic and diluted	149,214,819	146,484,651	147,971,737	140,157,620
Per share amount, basic and diluted	$ 0.56	$ 0.61	$ 2	$ 0.39

Other Expenses - Additional Inf

Other Expenses - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Management fee - percent of outstanding equity balance			1.50%
Incentive fee computation-percent of the product per agreement			20.00%
Incentive fee computation-percent of outstanding Equity per annum			7.00%
Management fees description			our Manager earns a base management fee in an amount equal to 1.50% per annum multiplied by our outstanding equity balance, as defined in the Management Agreement. In addition, our Manager is entitled to an incentive fee in an amount equal to the product of (i) 20% and (ii) the excess of (a) our Core Earnings (as defined in our Management Agreement) for the previous 12-month period over (b) an amount equal to 7.00% per annum multiplied by our outstanding Equity, provided that our Core Earnings over the prior three-year period is greater than zero. Core Earnings, as defined in our Management Agreement, is generally equal to our GAAP net income (loss), including realized gains and losses not otherwise recognized in current period GAAP net income (loss), and excluding (i) non-cash equity compensation expense, (ii) depreciation and amortization, (iii) unrealized gains (losses), (iv) certain non-cash items, and (v) incentive management fees.
Management fees	$ 19,342	$ 18,985	$ 60,094	$ 58,758
Manager [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Management fees	15,800	15,600	46,900	44,800
Total incentive compensation payments	3,600	$ 3,400	13,200	13,900
Accrued management and incentive fees payable	$ 19,300		19,300		$ 19,200
Payment for management and incentive fees			$ 59,900	40,700
Manager [Member] | Class A Common Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock Issued During Period, Value, Issued for Services				$ 19,300
Stock Issued During Period, Shares, Issued for Services				840,696

Other Expenses - Schedule of Ge

Other Expenses - Schedule of General and Administrative Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Professional services	$ 1,969	$ 1,715	$ 5,831	$ 5,130
Operating and other costs	792	878	2,093	3,212
Subtotal	2,761	2,593	7,924	8,342
Non-cash compensation expenses
Restricted class A common stock earned	7,907	8,524	23,762	25,603
Director stock-based compensation	173	125	422	375
Subtotal	8,080	8,649	24,184	25,978
Total general and administrative expenses	$ 10,841	$ 11,242	$ 32,108	$ 34,320

Other Expenses - Schedule of _2

Other Expenses - Schedule of General and Administrative Expenses (Parenthetical) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Multifamily [Member] | Joint Venture [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Expenses related Multifamily Joint Venture.	$ 110,000	$ 293,000	$ 543,000	$ 869,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	May 31, 2013	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Tax Credit Carryforward [Line Items]
Annual distribution of net taxable income for U.S. federal income tax not to apply to our earnings that we distribute (percent)				90.00%
Net taxable income subject to distribution (percent)				100.00%
Excise tax rate				4.00%
Income tax provision (benefit)		$ 70	$ 20	$ 346	$ 192
Deferred tax assets		0		0		$ 0
Deferred tax liabilities		0		$ 0		0
Common stock, shares issued	25,875,000			10,001,429	10,842,295
Net operating losses carried forward						$ 159,000
NOLs expiration date						Dec. 31, 2029
Open tax year				2017 2018 2019 2020
Internal Revenue Service [Member]
Tax Credit Carryforward [Line Items]
Net operating losses limit per annum		$ 2,000		$ 2,000
Net operating losses limitations				the availability of our NOLs is generally limited to $2.0 million per annum

Stock-Based Incentive Plans - A

Stock-Based Incentive Plans - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)Plansshares	Dec. 31, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of benefit plans | Plans	9
Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, vesting period	3 years
Number of shares of restricted class A common stock outstanding	1,143,320	1,627,890
Unrecognized compensation cost relating to nonvested share-based compensation | $	$ 33.6
Unrecognized compensation cost expected to be recognized over weighted average period	1 year
Expired Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available under plan	0
Vest in 2021 [Member] | Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding	239,145
Vest in 2022 [Member] | Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding	626,395
Vest in 2023 [Member] | Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding	277,780
Class A Common Stock [Member] | Stock Incentive Current Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available under plan	1,978,860
Maximum number of shares available under plan	5,000,000

Stock-Based Incentive Plans - M

Stock-Based Incentive Plans - Movement in Outstanding Shares of Restricted Class A Common Stock and Weighted-Average Grant Date Fair Value Per Share (Detail) - Restricted Class A Common Stock [Member]	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Class A Common Stock, Beginning Balance | shares	1,627,890
Restricted Class A Common Stock, Granted | shares	263,809
Restricted Class A Common Stock, Vested | shares	(718,799)
Restricted Class A Common Stock, Forfeited | shares	(29,580)
Restricted Class A Common Stock, Ending Balance | shares	1,143,320
Weighted-Average Grant Date Fair Value Per Share, Beginning Balance | $ / shares	$ 33.14
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	26.16
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	33.08
Weighted-Average Grant Date Fair Value Per Share, Forfeited | $ / shares	31.52
Weighted-Average Grant Date Fair Value Per Share, Ending Balance | $ / shares	$ 31.60

Fair Values - Assets and Liabil

Fair Values - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Derivatives	$ 35,858	$ 522
Liabilities
Derivatives	355	58,915
Recurring [Member]
Assets
Derivatives	35,858	522
Liabilities
Derivatives	355	58,915
Level 1 [Member] | Recurring [Member]
Assets
Derivatives	0	0
Liabilities
Derivatives	0	0
Level 2 [Member] | Recurring [Member]
Assets
Derivatives		522
Liabilities
Derivatives	355
Level 3 [Member] | Recurring [Member]
Assets
Derivatives	0	0
Liabilities
Derivatives	$ 0	$ 0

Fair Values - Schedule of Detai

Fair Values - Schedule of Details of Book Value, Face Amount, and Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financial assets
Cash and cash equivalents	$ 211,180	$ 289,970
Loans receivable, net	20,522,560	16,652,824
Debt securities held-to-maturity	79,200	79,200
Financial liabilities
Secured debt agreements, net, face amount	11,188,855	7,896,863
Securitized debt obligations, net	2,836,049	2,922,499
Securitized debt obligations, net,face amount	2,855,625	2,940,638
Term loans, net	1,352,706	1,062,766
Asset-specific debt , net, face amount	328,068	399,699
Book Value [Member]
Financial assets
Cash and cash equivalents	211,180	289,970
Loans receivable, net	20,276,078	16,399,166
Debt securities held-to-maturity	77,636	75,722
Financial liabilities
Secured debt, net	11,170,330	7,880,536
Securitized debt obligations, net	2,836,049	2,922,499
Asset-specific debt , net	320,895	391,269
Term loans, net	1,329,637	1,041,704
Convertible notes, net	618,985	616,389
Fair Value [Member]
Financial assets
Cash and cash equivalents	211,180	289,970
Loans receivable, net	20,358,824	16,447,192
Debt securities held-to-maturity	78,633	70,127
Financial liabilities
Secured debt, net	11,188,855	7,896,863
Securitized debt obligations, net	2,855,589	2,923,489
Asset-specific debt , net	328,068	399,699
Term loans, net	1,343,771	1,053,060
Convertible notes, net	633,845	621,568
Convertible Senior Note [Member]
Financial liabilities
Convertible notes, net, face amount	$ 622,500	$ 622,500

Variable Interest Entities - Su

Variable Interest Entities - Summary of Assets and Liabilities of Consolidated CLO and Single Asset Securitization VIE (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets:
Assets	$ 20,705,872	$ 16,958,955
Liabilities:
Liabilities	16,435,320	13,054,724
VIE [Member]
Assets:
Assets	3,503,362	3,587,950
Liabilities:
Liabilities	2,837,680	2,924,603
VIE [Member] | Loans Receivable [Member]
Assets:
Assets	3,475,000	3,520,130
Loans receivable, net	3,470,956	3,506,676
VIE [Member] | Current Expected Credit Loss Reserve [Member]
Assets:
Assets	(4,044)	(13,454)
VIE [Member] | Other Assets [Member]
Assets:
Assets	32,406	81,274
VIE [Member] | Securitized Debt Obligations, Net [Member]
Liabilities:
Liabilities	2,836,049	2,922,499
VIE [Member] | Other Liabilities [Member]
Liabilities:
Liabilities	$ 1,631	$ 2,104

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2021	Sep. 30, 2018
Variable Interest Entity [Line Items]
Subordinate risk retention interest notional amount		$ 99
Loans Receivable [Member]
Variable Interest Entity [Line Items]
Loan contributed to securitization	$ 517.5
2018 Single Asset Securitization [Member]
Variable Interest Entity [Line Items]
Single asset securitization principal amount		$ 1,000
Maximum exposure to loss	$ 77.6

Transactions with Related Par_2

Transactions with Related Parties - Additional Information (Detail) € in Millions, £ in Millions, kr in Billions	3 Months Ended				9 Months Ended
	Sep. 30, 2021USD ($)shares	Sep. 30, 2021GBP (£)	Jun. 30, 2021EUR (€)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)shares	Dec. 31, 2020USD ($)shares	Sep. 30, 2020USD ($)shares	Sep. 30, 2021GBP (£)shares	Sep. 30, 2021EUR (€)shares	Mar. 31, 2021USD ($)	Mar. 31, 2021SEK (kr)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2019EUR (€)	Sep. 30, 2019EUR (€)	Jun. 30, 2019USD ($)
Related Party Transaction [Line Items]
Non-cash expenses					$ 24,184,000		$ 25,978,000
Loan face amount	$ 20,522,560,000				20,522,560,000	$ 16,652,824,000
Unrealized (loss) gain on foreign currency translation Principal Balance					$ (228,637,000)
Restricted Class A Common Stock [Member]
Related Party Transaction [Line Items]
Shares held | shares	1,143,320				1,143,320	1,627,890		1,143,320	1,143,320
Senior Term Facility [Member]
Related Party Transaction [Line Items]
Senior term facility | £								£ 186
Percentage of senior loan borrowed	22.00%				22.00%			22.00%	22.00%
Increase of senior term loan facility | €			€ 100
Unrealized (loss) gain on foreign currency translation Principal Balance | £		£ 379.6
Senior Term Facility [Member] | Senior Loan Origination Under Marketed Process [Member]
Related Party Transaction [Line Items]
Loan face amount	$ 974,500,000				$ 974,500,000
Manager [Member]
Related Party Transaction [Line Items]
Management Agreement expiration date					Dec. 19, 2021
Management Agreement renewal term, description					the current term of which expires on December 19, 2021, and will be automatically renewed for a one-year term upon such date and each anniversary thereafter unless earlier terminated.
Accrued management and incentive fees payable	19,300,000				$ 19,300,000	$ 19,200,000
Management fees paid to Manager	21,500,000			$ 20,500,000	59,900,000	59,900,000
Expenses reimbursed to Manager	$ 141,000			416,000	$ 325,000		$ 839,000
Manager [Member] | Class A Common Stock [Member]
Related Party Transaction [Line Items]
Stock Issued During Period, Shares, Issued for Services | shares							840,696
Management fees paid to Manager							$ 19,300,000
Manager [Member] | Class A Common Stock [Member] | Restricted Class A Common Stock [Member]
Related Party Transaction [Line Items]
Shares held | shares	578,914				578,914			578,914	578,914
Non-cash expenses	$ 4,100,000			4,300,000	$ 12,200,000		12,800,000
Manager [Member] | Class A Common Stock [Member] | Restricted Class A Common Stock [Member] | Manager [Member]
Related Party Transaction [Line Items]
Non-cash expenses					18,500,000
Affiliates of Manager [Member] | Third-Party Service Provider [Member]
Related Party Transaction [Line Items]
Administrative services expenses incurred	100,000			98,000	291,000		369,000
BXMT Advisors Limited Liability Company and Affiliates [Member]
Related Party Transaction [Line Items]
Accrued management and incentive fees payable	19,300,000				19,300,000	$ 19,200,000
BXMT Advisors Limited Liability Company and Affiliates [Member] | B Two Term Loan [Member]
Related Party Transaction [Line Items]
Total incentive compensation payments					350,000
BXMT Advisors Limited Liability Company and Affiliates [Member] | B One Term Loan [Member]
Related Party Transaction [Line Items]
Total incentive compensation payments					950,000
Blackstone-Advised Investment Vehicles, or the Funds [Member] | B Two Term Loan [Member]
Related Party Transaction [Line Items]
Debt Securities	$ 20,000,000			$ 20,000,000	$ 20,000,000		$ 20,000,000
percentage of total secured term loans	5.00%			5.00%	5.00%		5.00%	5.00%	5.00%
Blackstone-Advised Investment Vehicles, or the Funds [Member] | B One Term Loan [Member]
Related Party Transaction [Line Items]
Debt Securities										$ 65,500,000			$ 65,500,000			$ 65,500,000
percentage of total secured term loans										7.00%	7.00%		7.00%	7.00%		7.00%
Blackstone-Advised Investment Vehicles, or the Funds [Member] | Senior Term Facility [Member]
Related Party Transaction [Line Items]
Loan face amount									€ 491		kr 10.2	$ 421,500,000		€ 1,600	€ 1,600
Senior term facility	$ 246,600,000		€ 50		$ 246,600,000						kr 5	$ 140,000,000		€ 250	€ 250
Minority participation in senior term facility	49.00%		10.00%		49.00%			49.00%	49.00%	49.00%	49.00%	33.00%	16.00%	16.00%
Unrealized (loss) gain on foreign currency translation Principal Balance	$ 503,300,000
Blackstone-Advised Investment Vehicles, or the Funds [Member] | Senior Term Facility [Member] | Senior Loan Origination Under Marketed Process [Member]
Related Party Transaction [Line Items]
Senior term facility	243,600,000				$ 243,600,000
Blackstone-Advised Investment Vehicles, or the Funds [Member] | Senior Term Facility [Member] | Additional Senior Loan Origination Under Marketed Process [Member]
Related Party Transaction [Line Items]
Senior term facility	243,600,000				243,600,000
Unaffiliated Third Parties [Member] | Senior Term Facility [Member] | Senior Loan Origination Under Marketed Process [Member]
Related Party Transaction [Line Items]
Senior term facility	$ 487,300,000				$ 487,300,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021USD ($)LoansDirectors
Commitments And Contingencies [Line Items]
Number of loans receivable | Loans	108
Number of independent directors entitled to annual compensation | Directors	6
Loans Receivable [Member]
Commitments And Contingencies [Line Items]
Unfunded loan commitments	$ 4,200,000,000
Aggregate unfunded loan commitments	$ 2,600,000,000
Weighted-average future funding period	3 years 2 months 12 days
Unfunded Commitments Related To Loans Receivable Excluding Identified Financing	$ 1,600,000,000
Five Independent Board of Directors [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	210,000
Annual cash compensation paid in the form of deferred stock units	115,000
Annual cash compensation paid in cash	95,000
Chairperson of Audit Committee [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	20,000
Audit Committee Members [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	10,000
Compensation and Corporate Governance Committees [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	10,000
Compensation and Corporate Governance Committees [Member] | Amendment One [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	15,000
Investment risk management committee [Member]
Commitments And Contingencies [Line Items]
Annual cash compensation	$ 7,500

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Principal Debt Repayments (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Debt Instrument [Line Items]
2021 (remainder of the year)	$ 134,104
2022	644,268
2023	2,218,470
2024	3,950,739
2025	1,422,933
2026	5,019,523
Thereafter	102,092
Total Obligation	13,492,129
Secured Debt Agreements[Member]
Debt Instrument [Line Items]
2021 (remainder of the year)	130,668
2022	228,030
2023	1,834,836
2024	3,937,001
2025	1,231,023
2026	3,725,205
Thereafter	102,092
Total Obligation	11,188,855
Asset-Specific Agreements [Member]
Debt Instrument [Line Items]
2021 (remainder of the year)	0
2022	0
2023	149,896
2024	0
2025	178,172
2026	0
Thereafter	0
Total Obligation	328,068
Secured Term Loans [Member]
Debt Instrument [Line Items]
2021 (remainder of the year)	3,436
2022	13,738
2023	13,738
2024	13,738
2025	13,738
2026	1,294,318
Thereafter	0
Total Obligation	1,352,706
Convertible Notes [Member]
Debt Instrument [Line Items]
2021 (remainder of the year)	0
2022	402,500
2023	220,000
2024	0
2025	0
2026	0
Thereafter	0
Total Obligation	$ 622,500

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Principal Debt Repayments (Parenthetical) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Debt Instrument [Line Items]
Debt Instrument Amortization Percentage	1.00%
Securitized debt obligations excluded from contractual obligations	$ 2,900
Non-consolidated securitized debt excluded from contractual obligations	997.6
Non-consolidated senior interests excluded from contractual obligations	$ 414.1

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 05, 2021	Sep. 30, 2021	Sep. 30, 2020
Proceeds from long term secured debt		$ 7,701,481	$ 2,317,616
Subsequent Event [Member] | Three Point Seven Five Senior Secured Notes due Two Thousand Twenty Seven [Member]
Face value	$ 400,000
Long term debt fixed interest rate percentage	3.75%
Long term debt date of maturity	Jan. 15, 2027
Subsequent Event [Member] | Bxmt Advisory Limited Liability Company And Affiliates [Member] | Three Point Seven Five Senior Secured Notes due Two Thousand Twenty Seven [Member]
Proceeds from long term secured debt	$ 400,000