Diamond Hill Investment (DHIL) 10-K 21 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 21, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	DIAMOND HILL INVESTMENT GROUP INC
Entity Central Index Key	909,108
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Entity Small Business	false
Entity Emerging Growth Company	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		3,500,730
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Public Float			$ 648,693,724

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 84,430,059	$ 76,602,108
Investments	203,488,217	138,476,022
Accounts receivable	20,290,283	19,220,279
Prepaid expenses	2,372,712	2,073,343
Income taxes receivable	0	4,114,962
Property and equipment, net of depreciation	3,680,472	4,057,901
Deferred taxes	11,466,100	5,843,704
Total assets	325,727,843	250,388,319
Liabilities
Accounts payable and accrued expenses	15,561,491	11,890,403
Accrued incentive compensation	26,754,167	25,496,500
Income taxes payable	2,768,681	0
Deferred compensation	22,387,874	20,480,790
Total liabilities	67,472,213	57,867,693
Redeemable noncontrolling interest	62,679,687	20,076,806
Permanent Shareholders’ Equity
Common stock, no par value 7,000,000 shares authorized; 3,499,285 issued and outstanding at December 31, 2018 (inclusive of 211,575 unvested shares); 3,470,428 issued and outstanding at December 31, 2017 (inclusive of 191,900 unvested shares)	124,933,060	118,209,111
Preferred stock, undesignated, 1,000,000 shares authorized and unissued	0	0
Deferred equity compensation	(22,008,054)	(19,134,963)
Retained Earnings	92,650,937	73,369,672
Total permanent shareholders’ equity	195,575,943	172,443,820
Total liabilities and shareholders’ equity	$ 325,727,843	$ 250,388,319
Book value per share (in dollars per share)	$ 55.89	$ 49.69

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, shares authorized	7,000,000	7,000,000
Common stock, shares issued	3,499,285	3,470,428
Common stock, shares outstanding	3,499,285	3,470,428
Common stock, unvested shares	211,575	191,900
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
REVENUES:
Total revenue	$ 145,627,748	$ 145,201,729	$ 136,103,075
OPERATING EXPENSES:
Compensation and related costs	53,853,670	54,855,972	52,264,843
General and administrative	11,648,925	14,036,681	12,621,831
Sales and marketing	5,242,848	4,994,525	4,263,143
Mutual fund administration	3,625,898	4,313,185	3,884,655
Total operating expenses	74,371,341	78,200,363	73,034,472
NET OPERATING INCOME	71,256,407	67,001,366	63,068,603
Investment income (loss), net	(6,272,678)	14,017,593	7,517,398
Gain on sale of subsidiary	0	0	2,675,766
INCOME BEFORE TAXES	64,983,729	81,018,959	73,261,767
Income tax expense	(18,669,341)	(29,417,290)	(26,667,635)
NET INCOME	46,314,388	51,601,669	46,594,132
Net loss (income) attributable to redeemable noncontrolling interest	1,061,441	(1,612,712)	(542,209)
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 47,375,829	$ 49,988,957	$ 46,051,923
Earnings per share attributable to common shareholders
Basic (in dollars per share)	$ 13.49	$ 14.49	$ 13.52
Diluted (in dollars per share)	$ 13.48	$ 14.48	$ 13.49
Weighted average shares outstanding
Basic (in shares)	3,512,470	3,448,824	3,407,408
Diluted (in shares)	3,514,528	3,451,838	3,413,391
Investment advisory
REVENUES:
Total revenue	$ 135,317,805	$ 132,688,462	$ 121,645,149
Mutual fund administration, net
REVENUES:
Total revenue	$ 10,309,943	$ 12,513,267	$ 14,457,926

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($)	Total	Common Stock	Deferred Equity Compensation	Retained Earnings
Beginning Balance (in shares) at Dec. 31, 2015		3,414,338
Beginning Balance at Dec. 31, 2015	$ 105,314,014	$ 102,536,527	$ (19,294,784)	$ 22,072,271
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock grants (in shares)		35,900
Issuance of restricted stock grants	0	$ 7,504,564	(7,504,564)
Amortization of restricted stock grants	6,466,797		6,466,797
Issuance of stock grants (in shares)		21,940
Issuance of stock grants	3,879,431	$ 3,879,431
Issuance of common stock related to 401k plan match (in shares)		9,466
Issuance of common stock related to 401k plan match	1,738,287	$ 1,738,287
Tax benefit from dividend payments related to restricted stock grants	1,372,996	1,372,996
Net excess tax benefit from vested restricted stock grants	4,895,907	$ 4,895,907
Shares withheld related to employee tax withholding (shares)		(53,018)
Shares withheld related to employee tax withholding	(10,029,464)	$ (10,029,464)
Forfeiture of restricted stock grants (in shares)		(17,070)
Forfeiture of restricted stock grants	0	$ (2,604,445)	2,604,445
Cash dividend paid of $6.00 in 2016, $7.00 in 2017, and $8.00 in 2018 per share respectively	(20,465,736)			(20,465,736)
Net income attributable to parent	46,051,923			46,051,923
Ending Balance (in shares) at Dec. 31, 2016		3,411,556
Ending Balance at Dec. 31, 2016	139,224,155	$ 109,293,803	(17,728,106)	47,658,458
Beginning balances attributable to redeemable noncontrolling interests at Dec. 31, 2015	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Net (loss) income attributable to redeemable noncontrolling interests	542,209
Net subscriptions of consolidated funds	9,266,723
Ending balances attributable to redeemable noncontrolling interests at Dec. 31, 2016	13,840,688
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock grants (in shares)		57,350
Issuance of restricted stock grants	0	$ 8,454,411	(8,454,411)
Amortization of restricted stock grants	6,871,284		6,871,284
Issuance of stock grants (in shares)		19,219
Issuance of stock grants	3,892,424	$ 3,892,424
Issuance of common stock related to 401k plan match (in shares)		8,478
Issuance of common stock related to 401k plan match	1,710,785	$ 1,710,785
Shares withheld related to employee tax withholding (shares)		(24,425)
Shares withheld related to employee tax withholding	(4,966,042)	$ (4,966,042)
Forfeiture of restricted stock grants (in shares)		(1,750)
Forfeiture of restricted stock grants	0	$ (176,270)	176,270
Cash dividend paid of $6.00 in 2016, $7.00 in 2017, and $8.00 in 2018 per share respectively	(24,277,743)			(24,277,743)
Net income attributable to parent	$ 49,988,957			49,988,957
Ending Balance (in shares) at Dec. 31, 2017	3,470,428	3,470,428
Ending Balance at Dec. 31, 2017	$ 172,443,820	$ 118,209,111	(19,134,963)	73,369,672
Increase (Decrease) in Temporary Equity [Roll Forward]
Net (loss) income attributable to redeemable noncontrolling interests	1,612,712
Net subscriptions of consolidated funds	4,623,406
Ending balances attributable to redeemable noncontrolling interests at Dec. 31, 2017	20,076,806
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock grants (in shares)		73,025
Issuance of restricted stock grants	0	$ 13,654,592	(13,654,592)
Amortization of restricted stock grants	6,664,875		6,664,875
Issuance of stock grants (in shares)		20,153
Issuance of stock grants	4,109,197	$ 4,109,197
Issuance of common stock related to 401k plan match (in shares)		11,967
Issuance of common stock related to 401k plan match	2,231,735	$ 2,231,735
Shares withheld related to employee tax withholding (shares)		(9,918)
Shares withheld related to employee tax withholding	(1,925,700)	$ (1,925,700)
Forfeiture of restricted stock grants (in shares)		(20,900)
Forfeiture of restricted stock grants	0	$ (4,116,626)	4,116,626
Repurchases of common stock (in shares)		(45,470)
Repurchases of common stock	(7,229,249)	$ (7,229,249)
Cash dividend paid of $6.00 in 2016, $7.00 in 2017, and $8.00 in 2018 per share respectively	(28,094,564)			(28,094,564)
Net income attributable to parent	$ 47,375,829			47,375,829
Ending Balance (in shares) at Dec. 31, 2018	3,499,285	3,499,285
Ending Balance at Dec. 31, 2018	$ 195,575,943	$ 124,933,060	$ (22,008,054)	$ 92,650,937
Increase (Decrease) in Temporary Equity [Roll Forward]
Net (loss) income attributable to redeemable noncontrolling interests	(1,061,441)
Net subscriptions of consolidated funds	27,219,682
New consolidations of Company sponsored investments	16,444,640
Ending balances attributable to redeemable noncontrolling interests at Dec. 31, 2018	$ 62,679,687

Consolidated Statements of Sh_2

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Dividend paid per share (in dollars per share)	$ 8	$ 7	$ 6

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 46,314,388	$ 51,601,669	$ 46,594,132
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,159,380	888,197	712,112
Share-based compensation	8,896,610	8,582,069	8,205,084
Decrease (increase) in accounts receivable	(1,014,839)	(1,615,070)	486,491
Change in current income taxes	6,883,643	(3,003,072)	6,559,150
Change in deferred income taxes	(5,622,396)	2,893,063	469,312
Gain on sale of subsidiary	0	0	(2,675,766)
Net loss / (gain) on investments	14,297,382	(9,730,751)	(5,471,469)
Net change in securities held by Consolidated Funds	(52,168,968)	(5,511,669)	(41,674,992)
Increase in accrued incentive compensation	5,366,864	6,705,424	4,578,431
Increase in deferred compensation	1,907,084	6,298,320	3,945,727
Excess income tax benefit from share-based compensation	0	0	(4,895,907)
Income tax benefit from dividends paid on restricted stock	0	0	(1,372,996)
Other changes in assets and liabilities	2,111,443	3,811,579	4,612,437
Net cash provided by operating activities	28,130,591	60,919,759	20,071,746
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(781,951)	(1,106,520)	(484,509)
Purchase of Company sponsored investments	(6,332,090)	(21,044,429)	(25,953,000)
Proceeds from sale of Company sponsored investments	2,353,144	2,597,130	19,543,607
Proceeds from sale of subsidiary, net of cash disposed	500,000	1,000,000	1,163,769
Net cash used in investing activities	(4,260,897)	(18,553,819)	(5,730,133)
CASH FLOWS FROM FINANCING ACTIVITIES:
Value of shares withheld related to employee tax withholding	(1,925,700)	(4,966,042)	(10,029,464)
Payment of dividends	(28,094,564)	(24,277,743)	(20,465,736)
Repurchase of common stock	21,207,770	6,290,077	9,599,783
Repurchase of common stock	(7,229,249)	0	0
Excess income tax benefit from share-based compensation	0	0	4,895,907
Income tax benefit from dividends paid on restricted stock	0	0	1,372,996
Net cash used in financing activities	(16,041,743)	(22,953,708)	(14,626,514)
CASH AND CASH EQUIVALENTS
Net change during the year	7,827,951	19,412,232	(284,901)
At beginning of year	76,602,108	57,189,876	57,474,777
At end of year	84,430,059	76,602,108	57,189,876
Supplemental cash flow information:
Income taxes paid	17,408,094	29,527,299	19,639,173
Supplemental disclosure of non-cash transactions:
Common stock issued as incentive compensation	4,109,197	3,892,424	3,879,431
Charitable donation of corporate investments and property and equipment	1,989,803	1,748,841	1,729,735
Cumulative-effect adjustment from the adoption of ASU 2015-02 (Note 2)	0	0	4,031,756
Net subscriptions (redemptions) of ETF Shares for marketable securities	$ 6,282,621	$ (1,555,305)	$ (244,200)

Business and Organization (Note

Business and Organization (Notes)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Organization	Business and Organization Diamond Hill Investment Group, Inc. (the “Company”), an Ohio corporation, derives its consolidated revenues and net income from investment advisory and fund administration services. Diamond Hill Capital Management, Inc. (“DHCM”), an Ohio corporation, is a wholly owned subsidiary of the Company and a registered investment adviser. DHCM is the investment adviser to the Diamond Hill Funds (the “Funds”), a series of open-end mutual funds, private investment funds (“Private Funds”), an exchange traded fund (the “ETF”), and other institutional accounts. In addition, DHCM is administrator for the Funds. Beacon Hill Fund Services, Inc. (“BHFS”) and BHIL Distributors, Inc. (“BHIL”), collectively operated as “Beacon Hill,” were former operating subsidiaries of the Company. The Company sold Beacon Hill on July 31, 2016. Prior to the sale, Beacon Hill provided compliance, treasury, underwriting and other fund administration services to investment advisers and mutual funds. See Note 11 for additional information regarding the sale of Beacon Hill.

Significant Accounting Policies

Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation The accompanying Consolidated Financial Statements of the Company have been prepared pursuant to the rules and regulations of the U. S. Securities and Exchange Commission (“SEC”) and in accordance with the instructions to Form 10-K. The Company believes that the disclosures contained herein are adequate to make the information presented not misleading. These Consolidated Financial Statements reflect, in the opinion of the Company, all material adjustments (which include only normal recurring adjustments) necessary to fairly present the Company’s financial position as of December 31, 2018 and 2017 , and results of operations for the years ended December 31, 2018 , 2017 and 2016 . The preparation of the Consolidated Financial Statements requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenue and expense during the reporting period. Estimates have been prepared on the basis of the most current and best available information, but actual results could differ materially from those estimates. Book value per share is computed by dividing total shareholders’ equity by the number of shares issued and outstanding at the end of the measurement period. Reclassification Certain prior period amounts and disclosures may have been reclassified to conform to the current period’s financial presentation. Principles of Consolidation The accompanying consolidated financial statements include the operations of the Company and its controlled subsidiaries. All inter-company transactions and balances have been eliminated in consolidation. The Company holds certain investments in the Funds and the ETF for general corporate investment purposes, to provide seed capital for newly formed strategies or to add capital to existing strategies. The Funds are organized in a series fund structure in which there are multiple mutual funds within one Trust. The Trust is an open-end investment company registered under the Investment Company Act of 1940, as amended (the”1940 Act”). The ETF is an individual series of ETF Series Solutions which is also an open-end investment company registered under the 1940 Act. Each of the individual mutual funds and the ETF represents a separate share class of a legal entity organized under the Trust. As of January 1, 2016, the Company adopted ASU 2015-02 - Consolidation (Topic 810): Amendments to the Consolidation Analysis (“ASU 2015-02”) and we have performed our consolidation analysis at the individual mutual fund and ETF level and have concluded the mutual funds and ETF are voting rights entities (“VREs”) because the structure of the investment product is such that the shareholders are deemed to have the power through voting rights to direct the activities that most significantly impact the entity’s economic performance. To the extent material, these investment products are consolidated if Company ownership, directly or indirectly, represents a majority interest (greater than 50%). The Company records redeemable noncontrolling interests in consolidated investments for which the Company’s ownership is less than 100%. The Company has consolidated the ETF, the Diamond Hill Core Bond Fund, the Diamond Hill High Yield Fund, and the Diamond Hill Global Fund (collectively, the “Consolidated Funds”) as of December 31, 2018 . We adopted ASU 2015-02 utilizing the modified retrospective transition method and have recorded a cumulative-effect adjustment to equity of $4.0 million as of January 1, 2016. Prior to the adoption of ASU 2015-02, we performed our analysis at the Trust level and concluded we did not need to consolidate the Funds or the ETF as we owned less than 1% of the voting interest in the respective Trusts. DHCM is the managing member of Diamond Hill General Partner, LLC (the “General Partner”), which is the general partner of Diamond Hill Investment Partners, L.P. (“DHIP”), and Diamond Hill International Equity Fund, L.P. (“DHIEF”), each a limited partnership (collectively, the “Partnerships” or “LPs”) whose underlying assets consist primarily of marketable securities. DHCM is wholly owned by the Company and is consolidated by us. Further, DHCM, through its control of the General Partner, has the power to direct each LP’s economic activities and the right to receive investment advisory fees that may be significant to the LPs. The Company concluded we did not have a variable interest in DHIP as the fees paid to the General Partner are considered to contain customary terms and conditions as found in the market for similar products and the Company has no equity ownership in DHIP. The Company concluded DHIEF was a variable interest entity (“VIE”) as DHCM has disproportionately less voting interest than economic interest, given that the limited partners have full power to remove the Company as the General Partner due to the existence of substantive kick-out rights. In addition, substantially all of the LPs’ activities are conducted on behalf of the General Partner which has disproportionately few voting rights. The Company concluded it is not the primary beneficiary of DHIEF as we lack the power to control the entity due to the existence of single-party kick-out rights where the limited partners have the unilateral ability to remove the General Partner without cause. DHCM’s investments in DHIEF are reported as a component of the Company’s investment portfolio, valued at DHCM’s respective share of the net income or loss of DHIEF. The LPs are not subject to lock-up periods and can be redeemed on demand. Gains and losses attributable to changes in the value of DHCM’s interests in the LPs are included in the Company’s reported investment income. The Company’s exposure to loss as a result of its involvement with the LPs is limited to the amount of its investments. DHCM is not obligated to provide, and has not provided, financial or other support to the LPs, other than its investments to date and its contractually provided investment advisory responsibilities. The Company has not provided liquidity arrangements, guarantees or other commitments to support the LPs’ operations, and the LPs’ creditors and interest holders have no recourse to the general credit of the Company. Certain board members and employees of the Company invest in the LPs and are not subject to a management fee or an incentive fee. These individuals receive no remuneration as a result of their personal investment in the LPs. The capital of the General Partner is not subject to a management fee or an incentive fee. Redeemable Noncontrolling Interest Redeemable noncontrolling interest represents third-party interests in the Consolidated Funds. This interest is redeemable at the option of the investors and therefore is not treated as permanent equity. Redeemable noncontrolling interest is recorded at redemption value, which approximates the fair value each reporting period. Segment Information Management has determined that the Company operates in one business segment, providing investment management and administration services to mutual funds, institutional accounts, and private investment funds. Therefore, no disclosures relating to operating segments are presented in the annual financial statements. Cash and Cash Equivalents Cash and cash equivalents include demand deposits and money market mutual funds held by DHCM. Accounts Receivable Accounts receivable are recorded when they are due and are presented on the balance sheet net of any allowance for doubtful accounts. Accounts receivable are written off when they are determined to be uncollectible. Any allowance for doubtful accounts is estimated based on the Company’s historical losses, existing conditions in the industry, and the financial stability of the individuals or entities that owe the receivable. No allowance for doubtful accounts was deemed necessary at December 31, 2018 or 2017 . Accounts receivable from the Funds were $9.4 million and $11.6 million as of December 31, 2018 and 2017 , respectively. Investments Management determines the appropriate classification of its investments at the time of purchase and re-evaluates its determination at each reporting period. Investments in the Funds we advise where the Company has neither control nor the ability to exercise significant influence, as well as securities held in the Consolidated Funds, are measured at fair value based on quoted market prices. Unrealized gains and losses are recorded as investment income (loss) in the Company’s consolidated statements of income. Investments classified as equity method investments represent investments in which the Company owns between 20-50% of the outstanding voting interests in the entity or when it is determined that the Company is able to exercise significant influence but not control over the investments. When using the equity method, the Company recognizes its respective share of the investee’s net income or loss for the period which is recorded as investment income in the Company’s consolidated statements of income. Property and Equipment Property and equipment, consisting of leasehold improvements, computer equipment, furniture, and fixtures, are carried at cost less accumulated depreciation. Accumulated depreciation was $5.2 million and $4.0 million as of December 31, 2018 and 2017 , respectively. Depreciation is calculated using the straight-line method over the estimated lives of the assets. New Accounting Guidance In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers”, which superseded existing accounting standards for revenue recognition and created a single framework. ASU 2014-09 requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This standard also specifies the accounting for certain costs to obtain or fulfill a contract with a customer. Our implementation efforts included a detailed review of revenue contracts within the scope of the guidance and an evaluation of the impact on the Company’s revenue recognition policies. No transition-related practical expedients were applied. The Company adopted this ASU on its effective date, January 1, 2018, and it had no impact on the timing of the Company’s revenue recognition. Revenue Recognition – General Revenue is recognized when performance obligations under the terms of a contract with a client are satisfied. The Company earns substantially all of its revenue from investment advisory and fund administration contracts. Investment advisory and administration fees, generally calculated as a percentage of assets under management (“AUM”), are recorded as revenue as services are performed. In addition to fixed fees based on a percentage of AUM, certain client accounts also provide periodic variable rate fees. Revenue earned for the years ended December 31, 2018 , 2017 and 2016 under contracts with clients include: Year Ended December 31, 2018 Investment advisory Mutual fund administration, net Total revenue Proprietary funds $ 105,228,977 $ 10,309,943 $ 115,538,920 Sub-advised funds and institutional accounts 30,088,828 — 30,088,828 $ 135,317,805 $ 10,309,943 $ 145,627,748 Year Ended December 31, 2017 Investment advisory Mutual fund administration, net Total revenue Proprietary funds $ 104,233,581 $ 12,513,267 $ 116,746,848 Sub-advised funds and institutional accounts 28,454,881 — 28,454,881 $ 132,688,462 $ 12,513,267 $ 145,201,729 Year Ended December 31, 2016 Investment advisory Mutual fund administration, net Total revenue Proprietary funds $ 88,861,650 $ 14,457,926 $ 103,319,576 Sub-advised funds and institutional accounts 32,783,499 — 32,783,499 $ 121,645,149 $ 14,457,926 $ 136,103,075 Revenue Recognition – Investment Advisory Fees The Company’s investment advisory contracts have a single performance obligation (the investment advisory services provided to the client) as the promised services are not separately identifiable from other promises in the contracts and, therefore, are not distinct. All performance obligations to provide advisory services are satisfied over time and the Company recognizes revenue as time passes. The fees we receive for our services under our investment advisory contracts are based on our AUM, which changes based on the value of securities held under each advisory contract. These fees are thereby constrained and represent variable consideration, and are excluded from revenue until the AUM on which our client is billed is no longer subject to market fluctuations. Revenue Recognition – Variable Rate Fees The Company manages certain client accounts that provide for variable rate fees. These fees are calculated based on client investment results over rolling five -year periods. The Company records variable rate fees at the end of the contract measurement period because the variable fees earned are constrained based on movements in the financial markets. During the years ended December 31, 2018 , 2017 , and 2016 , the Company recorded $1.4 million , $0.2 million , and $6.4 million , respectively, in variable rate fees. The table below shows AUM subject to variable rate fees and the amount of variable rate fees that would be recognized based upon investment results as of December 31, 2018 : As of December 31, 2018 AUM subject to variable rate fees Unearned variable rate fees Contractual Period Ending: Quarter Ending September 30, 2019 $ 31,391,099 $ 563,958 Quarter Ending March 31, 2020 11,224,113 10,585 Quarter Ending September 30, 2021 247,707,871 4,062,773 Total $ 290,323,083 $ 4,637,316 The contractual end dates highlight the time remaining until the variable rate fees are scheduled to be earned. The amount of variable rate fees that would be recognized based upon investments results as of December 31, 2018 will increase or decrease based on future client investment results through the contractual period end. There can be no assurance that the unearned amounts will ultimately be earned. Revenue Recognition – Mutual Fund Administration DHCM has an administrative and transfer agency services agreement with the Funds under which DHCM performs certain services for each Fund. These services include performance obligations including mutual fund administration, fund accounting, transfer agency and other related functions. These services are performed concurrently under our agreement with the Funds, and all performance obligations to provide these administrative services are satisfied over time, and the Company recognizes revenue as time passes. For performing these services each Fund pays DHCM a fee, which is calculated using an annual rate times the average daily net assets of each respective share class. These fees are thereby constrained and represent variable consideration, and are excluded from revenue until the AUM on which we bill the Funds is no longer subject to market fluctuations. The Funds have selected and contractually engaged certain vendors to fulfill various services to benefit the Funds’ shareholders or to satisfy regulatory requirements of the Funds. These services include, among others, required shareholder mailings, federal and state registrations, and legal and audit services. DHCM, in fulfilling a portion of its role under the administration agreement with the Funds, acts as agent to pay these obligations of the Funds. Each vendor is independently responsible for fulfillment of the services it has been engaged to provide and negotiates fees and terms with the management and board of trustees of the Funds. The fee that each Fund pays to DHCM is reviewed annually by the Funds’ board of trustees and specifically takes into account the contractual expenses that DHCM pays on behalf of the Funds. As a result, DHCM is not involved in the delivery or pricing of these services and bears no risk related to these services. Revenue has been recorded net of these Fund related expenses. In addition, DHCM advances the upfront commissions that are paid to brokers who sell Class C shares of the Funds. These advances are capitalized and amortized over 12 months to correspond with the repayments DHCM receives from the principal underwriter to recoup this commission advancement. Prior to the sale of Beacon Hill, the Company, through Beacon Hill, had underwriting and administrative service agreements with certain clients, including registered mutual funds. The fee arrangements varied from client to client based upon services provided and have been recorded as revenue under mutual fund administration on the Company’s consolidated statements of income. Part of Beacon Hill’s role as underwriter was to act as an agent on behalf of its mutual fund clients to receive 12b-1/service fees and commission revenue and facilitate the payment of those fees and commissions to third parties who provide services to the funds and their shareholders. The majority of 12b-1/service fees were paid to independent third parties and the remainder were retained by the Company as a reimbursement of expenses the Company had incurred. The amounts of 12b-1/service fees and commissions were determined by each mutual fund client, and Beacon Hill bore no financial risk related to these services. As a result, 12b-1/service fees and commission revenue was recorded net of the expense payments to third parties, in accordance with the appropriate accounting treatment for this agency relationship. Mutual fund administration gross and net revenue are summarized below: Year Ended December 31, 2018 2017 2016 Mutual fund administration: Administration revenue, gross $ 24,463,538 $ 26,219,881 $ 26,664,635 12b-1/service fees and commission revenue received from fund clients — — 6,360,400 12b-1/service fees and commission expense payments to third parties — — (5,660,430 ) Fund related expense (14,183,370 ) (13,748,445 ) (12,937,067 ) Revenue, net of related expenses 10,280,168 12,471,436 14,427,538 DHCM C-Share financing: Broker commission advance repayments 332,680 416,614 691,228 Broker commission amortization (302,905 ) (374,783 ) (660,840 ) Financing activity, net 29,775 41,831 30,388 Mutual fund administration revenue, net $ 10,309,943 $ 12,513,267 $ 14,457,926 Mutual fund administrative net revenue from the Funds was $10.3 million , $12.5 million , and $11.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Income Taxes The Company accounts for current and deferred income taxes through an asset and liability approach. Deferred tax assets are recognized for deductible temporary differences and deferred tax liabilities are recognized for taxable temporary differences. Deferred tax assets are reduced by a valuation allowance when it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment. The Company is subject to examination by federal and applicable state and local jurisdictions for various tax periods. The Company’s income tax positions are based on research and interpretations of the income tax laws and rulings in each of the jurisdictions in which it does business. Due to the subjectivity of interpretations of laws and rulings in each jurisdiction, the differences and interplay in tax laws among those jurisdictions, and the inherent uncertainty in estimating the final resolution of complex tax audit matters, the Company’s estimates of income tax liabilities may differ from actual payments or assessments. The Company regularly assesses its position with regard to tax exposures and records liabilities for these uncertain tax positions and related interest and penalties, if any, according to the principles of FASB ASC 740, Income Taxes . The Company records interest and penalties within income tax expense on the income statement. See Note 8 . Earnings Per Share Basic earnings per share (“EPS”) excludes dilution and is computed by dividing net income by the weighted average number of common shares outstanding for the period, which includes participating securities. Diluted EPS reflects the potential dilution of EPS due to unvested restricted stock units. See Note 9 . Newly Issued But Not Yet Adopted Accounting Guidance In February 2016, the FASB issued ASU 2016-02, “Leases”, which, among other things, requires lessees to recognize most leases on-balance sheet. This will increase the reported assets and liabilities of lessees - in some cases significantly. Lessor accounting remains substantially similar to current GAAP. ASU 2016-02 supersedes Topic 840, Leases . ASU 2016-02 is effective for annual and interim periods in fiscal years beginning after December 15, 2018. ASU 2016-02 mandates a modified retrospective transition method for all entities. We will adopt this standard on its effective date, January 1, 2019. While we continue evaluating the full impact this standard will have on our consolidated financial statements, we expect to record a right-of use asset and lease liability of approximately $3.6 million related to our office lease. We expect the adoption will have no impact on our consolidated statements of income. In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurements.” This update makes certain removals from, changes to and additions to existing disclosure requirements for fair value measurement. ASU 2018-13 does not change fair value measurements already required or permitted by existing standards. ASU 2018-13 is effective for financial statements issued for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Management does not believe that adoption of ASU 2018-13 will materially impact the Company’s financial statements.

Investments (Notes)

Investments (Notes)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The following table summarizes the carrying value of investments as of December 31, 2018 and 2017 : As of December 31, 2018 2017 Fair value investments: Securities held in Consolidated Funds (a) $ 153,730,480 $ 65,890,500 Company sponsored investments 33,418,088 36,541,818 Company sponsored equity method investments 16,339,649 36,043,704 Total Investments $ 203,488,217 $ 138,476,022 (a) Of the securities held in the Consolidated Funds as of December 31, 2018 , $84.7 million were held directly by the Company and $69.0 million were held by noncontrolling shareholders. Of the securities held in the Consolidated Funds as of December 31, 2017 , $42.6 million were held directly by the Company and $23.3 million were held by noncontrolling shareholders. The Company consolidated the ETF and Diamond Hill Core Bond Fund as of both December 31, 2018 and 2017 , respectively. During the year ended December 31, 2018 , the Company also consolidated the Diamond Hill Global Fund and the Diamond Hill High Yield Fund as we increased our ownership interest of each above 50% during the year. As of December 31, 2017 , these investments were classified as equity method investments. As of December 31, 2018 , our equity method investments consisted of the Diamond Hill Research Opportunities Fund and the Diamond Hill International Equity Fund, L.P., and our ownership percentages in each of these funds was 28% and 30% , respectively. As of December 31, 2017 , our equity method investments consisted of the Diamond Hill Research Opportunities Fund, the Diamond Hill High Yield Fund, the Diamond Hill Global Fund, L.P., and the Diamond Hill International Equity Fund, L.P., and our ownership percentages in these funds were 26% , 48% , 95% , and 30% , respectively. The Company’s equity method investments consist of cash, marketable equity securities and fixed income securities. The following table includes the condensed summary financial information from the Company’s equity method investments as of December 31, 2018 and 2017 and for the years ended December 31, 2018 , 2017 and 2016 : As of December 31, 2018 2017 Total assets $ 80,845,124 $ 144,118,745 Total liabilities 22,287,437 38,009,765 Net assets 58,557,687 106,108,980 DHCM’s portion of net assets 16,339,649 36,043,704 For the Year Ended December 31, 2018 2017 2016 Investment income $ 1,154,007 $ 2,944,836 $ 3,272,972 Expenses 978,322 1,176,896 1,409,896 Net realized gains 1,918,661 4,432,850 1,981,185 Net change in unrealized appreciation (depreciation) (10,229,319 ) 5,613,627 10,458,073 Net income (8,134,973 ) 11,814,417 14,302,334 DHCM’s portion of net income (2,400,467 ) 3,206,702 4,392,636

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company determines the fair value of our cash equivalents and certain investments using the following broad levels listed below: Level 1 - Unadjusted quoted prices for identical instruments in active markets. Level 2 - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-driven valuations in which all significant inputs are observable. Level 3 - Valuations derived from techniques in which significant inputs are unobservable. We do not value any investments using Level 3 inputs. These levels are not necessarily an indication of the risk or liquidity associated with investments. The following table summarizes investments that are recognized in our consolidated balance sheet using fair value measurements (excludes investments classified as equity method investments) determined based upon the differing levels as of December 31, 2018 and 2017 : December 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 80,690,647 $ — $ — $ 80,690,647 Fair value investments Securities held in Consolidated Funds (a) 43,595,438 110,135,042 — $ 153,730,480 Company sponsored investments 33,418,088 — — $ 33,418,088 December 31, 2017 Cash equivalents 72,669,083 — — $ 72,669,083 Fair value investments Securities held in Consolidated Funds (a) 24,618,578 41,271,922 — $ 65,890,500 Company sponsored investments 36,541,818 — — $ 36,541,818 (a) Of the securities held in the Consolidated Funds as of December 31, 2018 , $84.7 million were held directly by the Company and $69.0 million were held by noncontrolling shareholders. Of the securities held in the Consolidated Funds as of December 31, 2017 , $42.6 million were held directly by the Company and $23.3 million were held by noncontrolling shareholders. Level 1 investments are comprised of investments in registered investment companies (mutual funds) or equity securities held in the Consolidated Funds and include, as of December 31, 2018 and 2017 , $80.7 million and $72.7 million , respectively, of investments in money market mutual funds owned by DHCM that the Company classifies as cash equivalents. Level 2 investments are comprised of investments in debt securities held in the Consolidated Funds, which are valued by an independent pricing service using pricing techniques which take into account factors such as trading activity, readily available market quotations, yield, quality, coupon rate, maturity, type of issue, trading characteristics, call features, credit rates and other observable inputs. The Company determines transfers between fair value hierarchy levels at the end of the reporting period. There were no transfers in or out of the levels during any of the years ended December 31, 2018 , 2017 , and 2016 . Changes to fair values of the investments are recorded in the Company’s consolidated statements of income as investment income (loss), net.

Capital Stock (Notes)

Capital Stock (Notes)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Capital Stock	Capital Stock Common Shares The Company has only one class of securities outstanding, common shares, no par value per share. Authorization of Preferred Shares The Company’s Amended and Restated Articles of Incorporation authorize the issuance of 1,000,000 “blank check” preferred shares with such designations, rights and preferences as may be determined from time to time by the Company’s Board of Directors. The Board of Directors is authorized, without shareholder approval, to issue preferred shares with dividend, liquidation, conversion, voting, or other rights, which could adversely affect the voting or other rights of the holders of the common shares. There were no shares of preferred shares issued or outstanding at December 31, 2018 or 2017 .

Compensation Plans (Notes)

Compensation Plans (Notes)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation Plans	Compensation Plans Equity Incentive Plans 2014 Equity and Cash Incentive Plan At the Company’s annual shareholder meeting on April 30, 2014, shareholders approved the 2014 Equity and Cash Incentive Plan (“2014 Plan”). The 2014 Plan is intended to facilitate the Company’s ability to attract and retain staff, provide additional incentive to employees and directors, and promote the success of the Company’s business. The 2014 Plan authorizes the issuance of 600,000 common shares of the Company in various forms of equity awards. The 2014 Plan also authorizes cash incentive awards. As of December 31, 2018 , there were 287,354 common shares available for awards under the 2014 Plan. The 2014 Plan provides that the Board of Directors, or a committee appointed by the Board, may grant awards and otherwise administer the 2014 Plan. Restricted stock units and restricted stock grants issued under the 2014 Plan, which vest over time, are recorded as deferred compensation in the equity section of the balance sheet on the grant date and then recognized as compensation expense based on the grant date price over the vesting period of the respective grant. Stock grants issued under the 2014 Plan are recorded as compensation expense based on the grant date price. 2011 Equity and Cash Incentive Plan There are no longer any common shares available for future awards under the 2011 Equity and Cash Incentive Plan (the “2011 Plan”), although awards granted under the 2011 plan remain issued and outstanding. Restricted stock grants issued under the 2011 Plan, which vest over time, were recorded as deferred compensation in the equity section of the balance sheet on the grant date and then recognized as compensation expense based on the grant date price over the vesting period of the respective grant. Stock grants issued under the 2011 Plan were recorded as compensation expense based on the grant date price. Share-Based Payment Transactions The Company issues restricted stock units and restricted stock awards (sometimes referred to collectively as, “Restricted Stock”) under the 2014 Plan. Restricted stock units represent common shares which may be issued in the future, whereas restricted stock awards represent common shares issued and outstanding upon grant subject to vesting restrictions. The following table represents a roll-forward of outstanding Restricted Stock and related activity during the years ended December 31, 2018 and 2017 : Shares Weighted-Average Outstanding Restricted Stock as of December 31, 2016 223,800 $ 132.96 Grants issued 41,350 204.46 Grants vested (65,500 ) 98.81 Grants forfeited (1,750 ) 100.73 Outstanding Restricted Stock as of December 31, 2017 197,900 $ 165.60 Grants issued 70,025 195.00 Grants vested (32,450 ) 82.30 Grants forfeited (20,900 ) 196.97 Outstanding Restricted Stock as of December 31, 2018 214,575 $ 177.22 Total deferred equity compensation related to unvested Restricted Stock grants was $22.0 million as of December 31, 2018 . Compensation expense related to Restricted Stock grants is calculated based upon the fair market value of the common shares on grant date. The Company’s policy is to adjust compensation expense for forfeitures as they occur. The recognition of compensation expense related to deferred compensation over the remaining vesting periods is as follows: 2019 2020 2021 2022 2023 Thereafter Total $ 7,135,131 $ 5,671,192 $ 4,358,633 $ 3,371,500 $ 1,129,611 $ 341,987 $ 22,008,054 Stock Grant Transactions The following table represents shares issued as part of our incentive compensation program during the years ended December 31, 2018 , 2017 , and 2016 : Shares Issued Grant Date Value December 31, 2018 20,153 $ 4,109,197 December 31, 2017 19,219 3,892,424 December 31, 2016 21,940 3,879,431 401(k) Plan The Company sponsors a 401(k) plan in which all employees are eligible to participate. Employees may contribute a portion of their compensation subject to certain limits based on federal tax laws. Effective April 1, 2018, the Company increased its matching contributions of common shares of the Company with a value equal to 250 percent of the first six percent of an employee’s compensation contributed to the plan. Prior to April 1, 2018, the Company made matching contributions of common shares of the Company with a value equal to 200 percent of the first six percent of an employee’s compensation contribution to the plan. Employees become fully vested in the matching contributions after six plan years of employment. The following table summarizes the Company’s expenses attributable to the 401(k) plan during the years ended December 31, 2018 , 2017 and 2016 : Shares Issued Company Contribution December 31, 2018 11,967 $ 2,231,735 December 31, 2017 8,478 1,710,785 December 31, 2016 9,466 1,738,287 Deferred Compensation Plans The Company offers two deferred compensation plans, the Diamond Hill Fixed Term Deferred Compensation Plan and the Diamond Hill Variable Term Deferred Compensation Plan (collectively the “Plans”). Under the Plans, participants may elect to voluntarily defer, for a minimum of five years, certain incentive compensation, which the Company then contributes into the Plans. Each participant is responsible for designating investment options for assets they contribute, and the distribution paid to each participant reflects any gains or losses on the assets realized while in the Plans. Assets held in the Plans are included in the Company’s investment portfolio, and the associated obligation to participants is included in deferred compensation liability. Deferred compensation liability was $22.4 million and $20.5 million as of December 31, 2018 and 2017 , respectively.

Operating Leases (Notes)

Operating Leases (Notes)	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Operating Leases	Operating Leases The Company currently leases office space of approximately 37,829 square feet at one location. The following table summarizes the total lease and operating expenses for the years ended December 31, 2018 , 2017 and 2016 : For the year ended December 31, 2018 2017 2016 $ 970,143 $ 936,008 $ 882,231 The approximate future minimum lease payments under the operating lease are as follows: Future Minimum Lease Payments by Year Total 2019 2020 2021 2022 2023 Thereafter $ 3,853,831 $ 586,350 $ 614,721 $ 624,179 $ 624,179 $ 624,179 $ 780,223 In addition to the above lease payments, the Company is also responsible for normal operating expenses of the property. Such annual operating expenses were approximately $0.4 million in each of 2018 , 2017 and 2016 .

Income Taxes (Notes)

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes consists of: As of December 31, 2018 2017 2016 Current federal income tax provision $ 15,731,258 $ 24,749,832 $ 24,234,050 Current state and local income tax provision 8,560,479 1,774,395 1,964,273 Deferred income tax expense (benefit) (5,622,396 ) 2,893,063 469,312 Provision for income taxes $ 18,669,341 $ 29,417,290 $ 26,667,635 A reconciliation of income tax expense at the statutory federal rate to the Company’s income tax expense is as follows: 2018 2017 2016 Income tax computed at statutory rate $ 13,646,583 $ 28,356,636 $ 25,641,618 Expense (benefit) attributable to redeemable noncontrolling interests (a) 222,624 (564,449 ) (189,773 ) State and local income taxes, net of federal benefit 2,993,730 1,153,357 1,276,777 Change in uncertain state and local tax positions, net of federal benefit 2,982,337 — — Revaluation adjustment of net deferred tax assets (b) (917,288 ) 3,557,039 — Excess tax benefits on vesting of Restricted Stock (667,697 ) (2,420,250 ) — Income tax benefit from dividends paid on Restricted Stock (340,200 ) (418,583 ) — Interest and Penalties 786,711 — 15,748 Other (37,459 ) (246,460 ) (76,735 ) Income tax expense $ 18,669,341 $ 29,417,290 $ 26,667,635 (a) The provision for income taxes includes expense (benefit) attributable to the fact that the Company’s operations include the Consolidated Funds which are not subject to federal income taxes. Accordingly, a portion of the Company’s earnings are not subject to corporate tax levels. (b) The provision for income taxes for 2018 includes the remeasurement of our net deferred tax assets of $0.9 million due to the additional state and local tax we expect to pay in future tax periods. The provision for income taxes for 2017 includes a non-recurring charge of $3.6 million for the remeasurement of our net deferred tax assets to reflect the effect of the U.S. tax law changes enacted on December 22, 2017. Deferred income taxes and benefits arise from temporary differences between taxable income for financial statement and income tax return purposes. Net deferred tax assets consisted of the following at December 31, 2018 and 2017 : 2018 2017 Stock-based compensation $ 4,025,255 $ 2,868,719 Accrued compensation 6,684,531 5,795,204 Unrealized losses (gains) 1,323,181 (2,260,673 ) Property and equipment (498,271 ) (467,127 ) Other assets and liabilities (68,596 ) (92,419 ) Net deferred tax assets $ 11,466,100 $ 5,843,704 The net temporary differences incurred to date will reverse in future periods as the Company generates taxable earnings. The Company believes it is more likely than not that the results of future operations will generate sufficient taxable income to realize the net deferred tax assets recorded. The Company records a valuation allowance when it is more likely than not that some portion or all of the deferred tax assets will not be realized. As of December 31, 2018 , no valuation allowance was deemed necessary. The Company implemented ASU 2016-09, “Improvements to Employee Share-Based Payment Accounting” on January 1, 2017. Beginning January 1, 2017, any excess tax benefits or deficiencies from the vesting of stock awards are recognized through the income tax provision as opposed to common stock. For Restricted Stock, the Company receives an excess income tax benefit calculated as the tax effect of the difference between the fair market value of the stock at the time of grant and vesting. The Company also records income tax benefits from dividends paid on Restricted Stock. This change was required to be applied prospectively to all excess tax benefits and tax deficiencies after the date of adoption of the ASU. No adjustment is recorded for any windfall benefits previously recorded in common stock. In addition, all tax-related cash flows resulting from share based payments are now reported as operating activities in the statement of cash flows under the new guidance, rather than the prior requirement to present windfall tax benefits as an inflow from financing activities and an outflow from operating activities. The Company elected to adopt this change in cash flow presentation prospectively after the date of adoption of the ASU beginning January 1, 2017. Prior to January 1, 2017, the Company’s income taxes payable has been reduced by the tax benefits from equity incentive plan awards. These tax benefits were considered windfall tax benefits and were recognized as an increase to common stock. For Restricted Stock, the Company receives an excess income tax benefit calculated as the tax effect of the difference between the fair market value of the stock at the time of grant and vesting. The Company also records a tax benefit on dividends paid on Restricted Stock during the vesting period. The Company had net tax benefits from equity awards of $6.3 million for the year ended December 31, 2016. FASB ASC 740, Income Taxes, prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return and also provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company recognizes tax benefits related to positions taken, or expected to be taken, on its tax returns, only if the positions are "more-likely-than-not" sustainable. Once this threshold has been met, the Company’s measurement of its expected tax benefits is recognized in its financial statements. There was a $3.0 million increase to the total amount of unrecognized tax benefits related to tax uncertainties during 2018. The increase was the result of tax positions taken regarding state tax apportionment issues based on management’s judgment and latest information available. The Company and its subsidiaries file income tax returns with the Internal Revenue Service and the taxing authorities of various states. Generally the Company is subject to federal, state and local examinations by tax authorities for the tax years ended December 31, 2014 through 2018. The Company is currently under examination for tax years 2014 through 2016 with the New York State Department of Finance and Taxation. The New York State Department of Finance and Taxation issued a Consent to Field Audit Adjustment which means the Company and the New York State Department of Finance and Taxation are nearing the completion of the examination, however, the examination was not completed as of December 31, 2018. During 2018, the Company reassessed its New York City filing positions and filed a Voluntary Disclosure Agreement with the New York City Department of Finance. During 2018, the California Franchise Tax Board started the audit of the Company’s 2015 and 2016 tax years. No Notices of Proposed Assessments have been issued by the California Franchise Tax Board by December 31, 2018 and the audit is ongoing. The outcome of these examinations is not expected to have a material impact on the Company’s financial statements. The Company believes that some of these audits and negotiations will conclude within the next 12 months and that it is reasonably possible the amount of uncertain tax positions, including interest, may change by an immaterial amount due to settlements of audits. The amount of uncertain tax positions as of December 31, 2018 , 2017 and 2016 , respectively, which would impact the Company’s effective tax rate if recognized and a reconciliation of the beginning and ending amounts of uncertain tax positions is as follows: 2018 2017 2016 Uncertain tax positions, beginning of the year $ — $ — $ — Gross addition for tax positions of the current year — — — Gross additions for tax positions of prior years 2,982,337 — — Uncertain tax positions, end of year $ 2,982,337 $ — $ — In addition to the above uncertain tax positions, the Company recognized $0.8 million of interest and penalties which were accrued for during the year ended December 31, 2018 . No interest and penalties were accrued for uncertain tax positions during the years ended December 31, 2017 and 2016 .

Earnings Per Share (Notes)

Earnings Per Share (Notes)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The Company’s common shares outstanding consist of all shares issued and outstanding, including unvested restricted shares. Basic and diluted EPS are calculated under the two-class method. Restricted stock units are considered dilutive. The following table sets forth the computation for basic and diluted EPS and reconciliation between basic and diluted shares outstanding: Year Ended December 31, 2018 2017 2016 Net Income $ 46,314,388 $ 51,601,669 $ 46,594,132 Less: Net loss (income) attributable to redeemable noncontrolling interest 1,061,441 (1,612,712 ) (542,209 ) Net income attributable to common shareholders $ 47,375,829 $ 49,988,957 $ 46,051,923 Weighted average number of outstanding shares 3,512,470 3,448,824 3,407,408 Dilutive impact of restricted stock units 2,058 3,014 5,983 Weighted average number of outstanding shares - Diluted 3,514,528 3,451,838 3,413,391 Earnings per share attributable to common shareholders Basic $ 13.49 $ 14.49 $ 13.52 Diluted $ 13.48 $ 14.48 $ 13.49

Commitments and Contingencies (

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company indemnifies its directors, officers and certain of its employees for certain liabilities that might arise from their performance of their duties to the Company. From time to time, the Company is involved in legal matters relating to claims arising in the ordinary course of business. There are currently no such matters pending that the Company believes could have a material adverse effect on its consolidated financial statements. Additionally, in the normal course of business, the Company enters into agreements that contain a variety of representations and warranties and which provide general indemnifications. Certain agreements do not contain any limits on the Company’s liability and could involve future claims that may be made against the Company that have not yet occurred. Therefore, it is not possible to estimate the Company’s potential liability under these indemnities. Further, the Company maintains insurance policies that may provide coverage against certain claims under these indemnities.

Sale of Beacon Hill (Notes)

Sale of Beacon Hill (Notes)	12 Months Ended
	Dec. 31, 2018
Discontinued Operations and Disposal Groups [Abstract]
Sale of Beacon Hill	Sale of Beacon Hill On June 15, 2016, the Company sold the entirety of Beacon Hill’s business. The Company received $1.2 million in cash consideration, net of cash disposed, as well as contingent consideration with a fair value of $1.5 million in the form of a promissory note. The Company recorded a gain on sale of approximately $2.7 million during 2016. The Company collected $0.5 million and $1.0 million in the years ended December 31, 2018 and 2017 , respectively.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying Consolidated Financial Statements of the Company have been prepared pursuant to the rules and regulations of the U. S. Securities and Exchange Commission (“SEC”) and in accordance with the instructions to Form 10-K. The Company believes that the disclosures contained herein are adequate to make the information presented not misleading. These Consolidated Financial Statements reflect, in the opinion of the Company, all material adjustments (which include only normal recurring adjustments) necessary to fairly present the Company’s financial position as of December 31, 2018 and 2017 , and results of operations for the years ended December 31, 2018 , 2017 and 2016 . The preparation of the Consolidated Financial Statements requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenue and expense during the reporting period. Estimates have been prepared on the basis of the most current and best available information, but actual results could differ materially from those estimates. Book value per share is computed by dividing total shareholders’ equity by the number of shares issued and outstanding at the end of the measurement period.
Reclassification	Reclassification Certain prior period amounts and disclosures may have been reclassified to conform to the current period’s financial presentation.
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the operations of the Company and its controlled subsidiaries. All inter-company transactions and balances have been eliminated in consolidation. The Company holds certain investments in the Funds and the ETF for general corporate investment purposes, to provide seed capital for newly formed strategies or to add capital to existing strategies. The Funds are organized in a series fund structure in which there are multiple mutual funds within one Trust. The Trust is an open-end investment company registered under the Investment Company Act of 1940, as amended (the”1940 Act”). The ETF is an individual series of ETF Series Solutions which is also an open-end investment company registered under the 1940 Act. Each of the individual mutual funds and the ETF represents a separate share class of a legal entity organized under the Trust. As of January 1, 2016, the Company adopted ASU 2015-02 - Consolidation (Topic 810): Amendments to the Consolidation Analysis (“ASU 2015-02”) and we have performed our consolidation analysis at the individual mutual fund and ETF level and have concluded the mutual funds and ETF are voting rights entities (“VREs”) because the structure of the investment product is such that the shareholders are deemed to have the power through voting rights to direct the activities that most significantly impact the entity’s economic performance. To the extent material, these investment products are consolidated if Company ownership, directly or indirectly, represents a majority interest (greater than 50%). The Company records redeemable noncontrolling interests in consolidated investments for which the Company’s ownership is less than 100%. The Company has consolidated the ETF, the Diamond Hill Core Bond Fund, the Diamond Hill High Yield Fund, and the Diamond Hill Global Fund (collectively, the “Consolidated Funds”) as of December 31, 2018 . We adopted ASU 2015-02 utilizing the modified retrospective transition method and have recorded a cumulative-effect adjustment to equity of $4.0 million as of January 1, 2016. Prior to the adoption of ASU 2015-02, we performed our analysis at the Trust level and concluded we did not need to consolidate the Funds or the ETF as we owned less than 1% of the voting interest in the respective Trusts. DHCM is the managing member of Diamond Hill General Partner, LLC (the “General Partner”), which is the general partner of Diamond Hill Investment Partners, L.P. (“DHIP”), and Diamond Hill International Equity Fund, L.P. (“DHIEF”), each a limited partnership (collectively, the “Partnerships” or “LPs”) whose underlying assets consist primarily of marketable securities. DHCM is wholly owned by the Company and is consolidated by us. Further, DHCM, through its control of the General Partner, has the power to direct each LP’s economic activities and the right to receive investment advisory fees that may be significant to the LPs. The Company concluded we did not have a variable interest in DHIP as the fees paid to the General Partner are considered to contain customary terms and conditions as found in the market for similar products and the Company has no equity ownership in DHIP. The Company concluded DHIEF was a variable interest entity (“VIE”) as DHCM has disproportionately less voting interest than economic interest, given that the limited partners have full power to remove the Company as the General Partner due to the existence of substantive kick-out rights. In addition, substantially all of the LPs’ activities are conducted on behalf of the General Partner which has disproportionately few voting rights. The Company concluded it is not the primary beneficiary of DHIEF as we lack the power to control the entity due to the existence of single-party kick-out rights where the limited partners have the unilateral ability to remove the General Partner without cause. DHCM’s investments in DHIEF are reported as a component of the Company’s investment portfolio, valued at DHCM’s respective share of the net income or loss of DHIEF. The LPs are not subject to lock-up periods and can be redeemed on demand. Gains and losses attributable to changes in the value of DHCM’s interests in the LPs are included in the Company’s reported investment income. The Company’s exposure to loss as a result of its involvement with the LPs is limited to the amount of its investments. DHCM is not obligated to provide, and has not provided, financial or other support to the LPs, other than its investments to date and its contractually provided investment advisory responsibilities. The Company has not provided liquidity arrangements, guarantees or other commitments to support the LPs’ operations, and the LPs’ creditors and interest holders have no recourse to the general credit of the Company. Certain board members and employees of the Company invest in the LPs and are not subject to a management fee or an incentive fee. These individuals receive no remuneration as a result of their personal investment in the LPs. The capital of the General Partner is not subject to a management fee or an incentive fee.
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interest Redeemable noncontrolling interest represents third-party interests in the Consolidated Funds. This interest is redeemable at the option of the investors and therefore is not treated as permanent equity. Redeemable noncontrolling interest is recorded at redemption value, which approximates the fair value each reporting period.
Segment Information	Segment Information Management has determined that the Company operates in one business segment, providing investment management and administration services to mutual funds, institutional accounts, and private investment funds. Therefore, no disclosures relating to operating segments are presented in the annual financial statements.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include demand deposits and money market mutual funds held by DHCM.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded when they are due and are presented on the balance sheet net of any allowance for doubtful accounts. Accounts receivable are written off when they are determined to be uncollectible. Any allowance for doubtful accounts is estimated based on the Company’s historical losses, existing conditions in the industry, and the financial stability of the individuals or entities that owe the receivable.
Investments	Investments Management determines the appropriate classification of its investments at the time of purchase and re-evaluates its determination at each reporting period. Investments in the Funds we advise where the Company has neither control nor the ability to exercise significant influence, as well as securities held in the Consolidated Funds, are measured at fair value based on quoted market prices. Unrealized gains and losses are recorded as investment income (loss) in the Company’s consolidated statements of income. Investments classified as equity method investments represent investments in which the Company owns between 20-50% of the outstanding voting interests in the entity or when it is determined that the Company is able to exercise significant influence but not control over the investments. When using the equity method, the Company recognizes its respective share of the investee’s net income or loss for the period which is recorded as investment income in the Company’s consolidated statements of income.
Property and Equipment	Property and Equipment Property and equipment, consisting of leasehold improvements, computer equipment, furniture, and fixtures, are carried at cost less accumulated depreciation. Accumulated depreciation was $5.2 million and $4.0 million as of December 31, 2018 and 2017 , respectively. Depreciation is calculated using the straight-line method over the estimated lives of the assets.
Revenue Recognition	Revenue Recognition – Mutual Fund Administration DHCM has an administrative and transfer agency services agreement with the Funds under which DHCM performs certain services for each Fund. These services include performance obligations including mutual fund administration, fund accounting, transfer agency and other related functions. These services are performed concurrently under our agreement with the Funds, and all performance obligations to provide these administrative services are satisfied over time, and the Company recognizes revenue as time passes. For performing these services each Fund pays DHCM a fee, which is calculated using an annual rate times the average daily net assets of each respective share class. These fees are thereby constrained and represent variable consideration, and are excluded from revenue until the AUM on which we bill the Funds is no longer subject to market fluctuations. The Funds have selected and contractually engaged certain vendors to fulfill various services to benefit the Funds’ shareholders or to satisfy regulatory requirements of the Funds. These services include, among others, required shareholder mailings, federal and state registrations, and legal and audit services. DHCM, in fulfilling a portion of its role under the administration agreement with the Funds, acts as agent to pay these obligations of the Funds. Each vendor is independently responsible for fulfillment of the services it has been engaged to provide and negotiates fees and terms with the management and board of trustees of the Funds. The fee that each Fund pays to DHCM is reviewed annually by the Funds’ board of trustees and specifically takes into account the contractual expenses that DHCM pays on behalf of the Funds. As a result, DHCM is not involved in the delivery or pricing of these services and bears no risk related to these services. Revenue has been recorded net of these Fund related expenses. In addition, DHCM advances the upfront commissions that are paid to brokers who sell Class C shares of the Funds. These advances are capitalized and amortized over 12 months to correspond with the repayments DHCM receives from the principal underwriter to recoup this commission advancement. Prior to the sale of Beacon Hill, the Company, through Beacon Hill, had underwriting and administrative service agreements with certain clients, including registered mutual funds. The fee arrangements varied from client to client based upon services provided and have been recorded as revenue under mutual fund administration on the Company’s consolidated statements of income. Part of Beacon Hill’s role as underwriter was to act as an agent on behalf of its mutual fund clients to receive 12b-1/service fees and commission revenue and facilitate the payment of those fees and commissions to third parties who provide services to the funds and their shareholders. The majority of 12b-1/service fees were paid to independent third parties and the remainder were retained by the Company as a reimbursement of expenses the Company had incurred. The amounts of 12b-1/service fees and commissions were determined by each mutual fund client, and Beacon Hill bore no financial risk related to these services. As a result, 12b-1/service fees and commission revenue was recorded net of the expense payments to third parties, in accordance with the appropriate accounting treatment for this agency relationship. Revenue Recognition – Investment Advisory Fees The Company’s investment advisory contracts have a single performance obligation (the investment advisory services provided to the client) as the promised services are not separately identifiable from other promises in the contracts and, therefore, are not distinct. All performance obligations to provide advisory services are satisfied over time and the Company recognizes revenue as time passes. The fees we receive for our services under our investment advisory contracts are based on our AUM, which changes based on the value of securities held under each advisory contract. These fees are thereby constrained and represent variable consideration, and are excluded from revenue until the AUM on which our client is billed is no longer subject to market fluctuations. Revenue Recognition – Variable Rate Fees The Company manages certain client accounts that provide for variable rate fees. These fees are calculated based on client investment results over rolling five -year periods. The Company records variable rate fees at the end of the contract measurement period because the variable fees earned are constrained based on movements in the financial markets. Revenue Recognition – General Revenue is recognized when performance obligations under the terms of a contract with a client are satisfied. The Company earns substantially all of its revenue from investment advisory and fund administration contracts. Investment advisory and administration fees, generally calculated as a percentage of assets under management (“AUM”), are recorded as revenue as services are performed. In addition to fixed fees based on a percentage of AUM, certain client accounts also provide periodic variable rate fees.
Income Taxes	Income Taxes The Company accounts for current and deferred income taxes through an asset and liability approach. Deferred tax assets are recognized for deductible temporary differences and deferred tax liabilities are recognized for taxable temporary differences. Deferred tax assets are reduced by a valuation allowance when it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment. The Company is subject to examination by federal and applicable state and local jurisdictions for various tax periods. The Company’s income tax positions are based on research and interpretations of the income tax laws and rulings in each of the jurisdictions in which it does business. Due to the subjectivity of interpretations of laws and rulings in each jurisdiction, the differences and interplay in tax laws among those jurisdictions, and the inherent uncertainty in estimating the final resolution of complex tax audit matters, the Company’s estimates of income tax liabilities may differ from actual payments or assessments. The Company regularly assesses its position with regard to tax exposures and records liabilities for these uncertain tax positions and related interest and penalties, if any, according to the principles of FASB ASC 740, Income Taxes . The Company records interest and penalties within income tax expense on the income statement. See Note 8 .
Earnings Per Share	Earnings Per Share Basic earnings per share (“EPS”) excludes dilution and is computed by dividing net income by the weighted average number of common shares outstanding for the period, which includes participating securities. Diluted EPS reflects the potential dilution of EPS due to unvested restricted stock units. See Note 9 .
New and Newly Issued But Not Yet Adopted Accounting Guidance	New Accounting Guidance In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers”, which superseded existing accounting standards for revenue recognition and created a single framework. ASU 2014-09 requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This standard also specifies the accounting for certain costs to obtain or fulfill a contract with a customer. Our implementation efforts included a detailed review of revenue contracts within the scope of the guidance and an evaluation of the impact on the Company’s revenue recognition policies. No transition-related practical expedients were applied. The Company adopted this ASU on its effective date, January 1, 2018, and it had no impact on the timing of the Company’s revenue recognition. Newly Issued But Not Yet Adopted Accounting Guidance In February 2016, the FASB issued ASU 2016-02, “Leases”, which, among other things, requires lessees to recognize most leases on-balance sheet. This will increase the reported assets and liabilities of lessees - in some cases significantly. Lessor accounting remains substantially similar to current GAAP. ASU 2016-02 supersedes Topic 840, Leases . ASU 2016-02 is effective for annual and interim periods in fiscal years beginning after December 15, 2018. ASU 2016-02 mandates a modified retrospective transition method for all entities. We will adopt this standard on its effective date, January 1, 2019. While we continue evaluating the full impact this standard will have on our consolidated financial statements, we expect to record a right-of use asset and lease liability of approximately $3.6 million related to our office lease. We expect the adoption will have no impact on our consolidated statements of income. In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurements.” This update makes certain removals from, changes to and additions to existing disclosure requirements for fair value measurement. ASU 2018-13 does not change fair value measurements already required or permitted by existing standards. ASU 2018-13 is effective for financial statements issued for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Management does not believe that adoption of ASU 2018-13 will materially impact the Company’s financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Revenue under contracts with clients	Revenue earned for the years ended December 31, 2018 , 2017 and 2016 under contracts with clients include: Year Ended December 31, 2018 Investment advisory Mutual fund administration, net Total revenue Proprietary funds $ 105,228,977 $ 10,309,943 $ 115,538,920 Sub-advised funds and institutional accounts 30,088,828 — 30,088,828 $ 135,317,805 $ 10,309,943 $ 145,627,748 Year Ended December 31, 2017 Investment advisory Mutual fund administration, net Total revenue Proprietary funds $ 104,233,581 $ 12,513,267 $ 116,746,848 Sub-advised funds and institutional accounts 28,454,881 — 28,454,881 $ 132,688,462 $ 12,513,267 $ 145,201,729 Year Ended December 31, 2016 Investment advisory Mutual fund administration, net Total revenue Proprietary funds $ 88,861,650 $ 14,457,926 $ 103,319,576 Sub-advised funds and institutional accounts 32,783,499 — 32,783,499 $ 121,645,149 $ 14,457,926 $ 136,103,075
Assets under management (AUM) subject to variable rate fees and the variable rate fees	The table below shows AUM subject to variable rate fees and the amount of variable rate fees that would be recognized based upon investment results as of December 31, 2018 : As of December 31, 2018 AUM subject to variable rate fees Unearned variable rate fees Contractual Period Ending: Quarter Ending September 30, 2019 $ 31,391,099 $ 563,958 Quarter Ending March 31, 2020 11,224,113 10,585 Quarter Ending September 30, 2021 247,707,871 4,062,773 Total $ 290,323,083 $ 4,637,316
Mutual fund administration gross and net revenue	Mutual fund administration gross and net revenue are summarized below: Year Ended December 31, 2018 2017 2016 Mutual fund administration: Administration revenue, gross $ 24,463,538 $ 26,219,881 $ 26,664,635 12b-1/service fees and commission revenue received from fund clients — — 6,360,400 12b-1/service fees and commission expense payments to third parties — — (5,660,430 ) Fund related expense (14,183,370 ) (13,748,445 ) (12,937,067 ) Revenue, net of related expenses 10,280,168 12,471,436 14,427,538 DHCM C-Share financing: Broker commission advance repayments 332,680 416,614 691,228 Broker commission amortization (302,905 ) (374,783 ) (660,840 ) Financing activity, net 29,775 41,831 30,388 Mutual fund administration revenue, net $ 10,309,943 $ 12,513,267 $ 14,457,926

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of market value of investments	The following table summarizes the carrying value of investments as of December 31, 2018 and 2017 : As of December 31, 2018 2017 Fair value investments: Securities held in Consolidated Funds (a) $ 153,730,480 $ 65,890,500 Company sponsored investments 33,418,088 36,541,818 Company sponsored equity method investments 16,339,649 36,043,704 Total Investments $ 203,488,217 $ 138,476,022 (a) Of the securities held in the Consolidated Funds as of December 31, 2018 , $84.7 million were held directly by the Company and $69.0 million were held by noncontrolling shareholders. Of the securities held in the Consolidated Funds as of December 31, 2017 , $42.6 million were held directly by the Company and $23.3 million were held by noncontrolling shareholders.
Equity Method Investments	The following table includes the condensed summary financial information from the Company’s equity method investments as of December 31, 2018 and 2017 and for the years ended December 31, 2018 , 2017 and 2016 : As of December 31, 2018 2017 Total assets $ 80,845,124 $ 144,118,745 Total liabilities 22,287,437 38,009,765 Net assets 58,557,687 106,108,980 DHCM’s portion of net assets 16,339,649 36,043,704 For the Year Ended December 31, 2018 2017 2016 Investment income $ 1,154,007 $ 2,944,836 $ 3,272,972 Expenses 978,322 1,176,896 1,409,896 Net realized gains 1,918,661 4,432,850 1,981,185 Net change in unrealized appreciation (depreciation) (10,229,319 ) 5,613,627 10,458,073 Net income (8,134,973 ) 11,814,417 14,302,334 DHCM’s portion of net income (2,400,467 ) 3,206,702 4,392,636

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Summary of Investment Values Based Upon Fair Value Hierarchy	The following table summarizes investments that are recognized in our consolidated balance sheet using fair value measurements (excludes investments classified as equity method investments) determined based upon the differing levels as of December 31, 2018 and 2017 : December 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 80,690,647 $ — $ — $ 80,690,647 Fair value investments Securities held in Consolidated Funds (a) 43,595,438 110,135,042 — $ 153,730,480 Company sponsored investments 33,418,088 — — $ 33,418,088 December 31, 2017 Cash equivalents 72,669,083 — — $ 72,669,083 Fair value investments Securities held in Consolidated Funds (a) 24,618,578 41,271,922 — $ 65,890,500 Company sponsored investments 36,541,818 — — $ 36,541,818 (a) Of the securities held in the Consolidated Funds as of December 31, 2018 , $84.7 million were held directly by the Company and $69.0 million were held by noncontrolling shareholders. Of the securities held in the Consolidated Funds as of December 31, 2017 , $42.6 million were held directly by the Company and $23.3 million were held by noncontrolling shareholders.

Compensation Plans (Tables)

Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Roll-forward of outstanding restricted stock grants issued	The following table represents a roll-forward of outstanding Restricted Stock and related activity during the years ended December 31, 2018 and 2017 : Shares Weighted-Average Outstanding Restricted Stock as of December 31, 2016 223,800 $ 132.96 Grants issued 41,350 204.46 Grants vested (65,500 ) 98.81 Grants forfeited (1,750 ) 100.73 Outstanding Restricted Stock as of December 31, 2017 197,900 $ 165.60 Grants issued 70,025 195.00 Grants vested (32,450 ) 82.30 Grants forfeited (20,900 ) 196.97 Outstanding Restricted Stock as of December 31, 2018 214,575 $ 177.22
Expense recognition of deferred compensation	The recognition of compensation expense related to deferred compensation over the remaining vesting periods is as follows: 2019 2020 2021 2022 2023 Thereafter Total $ 7,135,131 $ 5,671,192 $ 4,358,633 $ 3,371,500 $ 1,129,611 $ 341,987 $ 22,008,054
Schedule of Grants Issued and Grant Date Fair Value	The following table represents shares issued as part of our incentive compensation program during the years ended December 31, 2018 , 2017 , and 2016 : Shares Issued Grant Date Value December 31, 2018 20,153 $ 4,109,197 December 31, 2017 19,219 3,892,424 December 31, 2016 21,940 3,879,431
Summary of company expenses attributable to the 401(k) Plan	The following table summarizes the Company’s expenses attributable to the 401(k) plan during the years ended December 31, 2018 , 2017 and 2016 : Shares Issued Company Contribution December 31, 2018 11,967 $ 2,231,735 December 31, 2017 8,478 1,710,785 December 31, 2016 9,466 1,738,287

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Summary of total lease and operating expense	The following table summarizes the total lease and operating expenses for the years ended December 31, 2018 , 2017 and 2016 : For the year ended December 31, 2018 2017 2016 $ 970,143 $ 936,008 $ 882,231
Future minimum lease payments under the operating leases	The approximate future minimum lease payments under the operating lease are as follows: Future Minimum Lease Payments by Year Total 2019 2020 2021 2022 2023 Thereafter $ 3,853,831 $ 586,350 $ 614,721 $ 624,179 $ 624,179 $ 624,179 $ 780,223

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Summary of consolidated provision for income taxes	The provision for income taxes consists of: As of December 31, 2018 2017 2016 Current federal income tax provision $ 15,731,258 $ 24,749,832 $ 24,234,050 Current state and local income tax provision 8,560,479 1,774,395 1,964,273 Deferred income tax expense (benefit) (5,622,396 ) 2,893,063 469,312 Provision for income taxes $ 18,669,341 $ 29,417,290 $ 26,667,635
Summary of reconciliation of income tax expense	A reconciliation of income tax expense at the statutory federal rate to the Company’s income tax expense is as follows: 2018 2017 2016 Income tax computed at statutory rate $ 13,646,583 $ 28,356,636 $ 25,641,618 Expense (benefit) attributable to redeemable noncontrolling interests (a) 222,624 (564,449 ) (189,773 ) State and local income taxes, net of federal benefit 2,993,730 1,153,357 1,276,777 Change in uncertain state and local tax positions, net of federal benefit 2,982,337 — — Revaluation adjustment of net deferred tax assets (b) (917,288 ) 3,557,039 — Excess tax benefits on vesting of Restricted Stock (667,697 ) (2,420,250 ) — Income tax benefit from dividends paid on Restricted Stock (340,200 ) (418,583 ) — Interest and Penalties 786,711 — 15,748 Other (37,459 ) (246,460 ) (76,735 ) Income tax expense $ 18,669,341 $ 29,417,290 $ 26,667,635 (a) The provision for income taxes includes expense (benefit) attributable to the fact that the Company’s operations include the Consolidated Funds which are not subject to federal income taxes. Accordingly, a portion of the Company’s earnings are not subject to corporate tax levels. (b) The provision for income taxes for 2018 includes the remeasurement of our net deferred tax assets of $0.9 million due to the additional state and local tax we expect to pay in future tax periods. The provision for income taxes for 2017 includes a non-recurring charge of $3.6 million for the remeasurement of our net deferred tax assets to reflect the effect of the U.S. tax law changes enacted on December 22, 2017.
Summary of deferred tax assets and liabilities	Net deferred tax assets consisted of the following at December 31, 2018 and 2017 : 2018 2017 Stock-based compensation $ 4,025,255 $ 2,868,719 Accrued compensation 6,684,531 5,795,204 Unrealized losses (gains) 1,323,181 (2,260,673 ) Property and equipment (498,271 ) (467,127 ) Other assets and liabilities (68,596 ) (92,419 ) Net deferred tax assets $ 11,466,100 $ 5,843,704
Reconciliation of uncertain tax positions	The amount of uncertain tax positions as of December 31, 2018 , 2017 and 2016 , respectively, which would impact the Company’s effective tax rate if recognized and a reconciliation of the beginning and ending amounts of uncertain tax positions is as follows: 2018 2017 2016 Uncertain tax positions, beginning of the year $ — $ — $ — Gross addition for tax positions of the current year — — — Gross additions for tax positions of prior years 2,982,337 — — Uncertain tax positions, end of year $ 2,982,337 $ — $ —

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Computation for earnings per share	The following table sets forth the computation for basic and diluted EPS and reconciliation between basic and diluted shares outstanding: Year Ended December 31, 2018 2017 2016 Net Income $ 46,314,388 $ 51,601,669 $ 46,594,132 Less: Net loss (income) attributable to redeemable noncontrolling interest 1,061,441 (1,612,712 ) (542,209 ) Net income attributable to common shareholders $ 47,375,829 $ 49,988,957 $ 46,051,923 Weighted average number of outstanding shares 3,512,470 3,448,824 3,407,408 Dilutive impact of restricted stock units 2,058 3,014 5,983 Weighted average number of outstanding shares - Diluted 3,514,528 3,451,838 3,413,391 Earnings per share attributable to common shareholders Basic $ 13.49 $ 14.49 $ 13.52 Diluted $ 13.48 $ 14.48 $ 13.49

Significant Accounting Polici_4

Significant Accounting Policies - Revenue From Contracts with Customers (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue	$ 145,627,748	$ 145,201,729	$ 136,103,075
Investment advisory
Disaggregation of Revenue [Line Items]
Revenue	135,317,805	132,688,462	121,645,149
Mutual fund administration revenue, net
Disaggregation of Revenue [Line Items]
Revenue	10,309,943	12,513,267	14,457,926
Proprietary funds
Disaggregation of Revenue [Line Items]
Revenue	115,538,920	116,746,848	103,319,576
Proprietary funds | Investment advisory
Disaggregation of Revenue [Line Items]
Revenue	105,228,977	104,233,581	88,861,650
Proprietary funds | Mutual fund administration revenue, net
Disaggregation of Revenue [Line Items]
Revenue	10,309,943	12,513,267	14,457,926
Sub-advised funds and institutional accounts
Disaggregation of Revenue [Line Items]
Revenue	30,088,828	28,454,881	32,783,499
Sub-advised funds and institutional accounts | Investment advisory
Disaggregation of Revenue [Line Items]
Revenue	30,088,828	28,454,881	32,783,499
Sub-advised funds and institutional accounts | Mutual fund administration revenue, net
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 0	$ 0

Significant Accounting Polici_5

Significant Accounting Policies - Summary of Assets Under Management Subject to Fees (Details)	12 Months Ended
	Dec. 31, 2018USD ($)
Quarter Ending September 30, 2019
Principal Transaction Revenue [Line Items]
AUM subject to variable rate fees	$ 31,391,099
Unearned variable rate fees	563,958
Quarter Ending March 31, 2020
Principal Transaction Revenue [Line Items]
AUM subject to variable rate fees	11,224,113
Unearned variable rate fees	10,585
Quarter Ending September 30, 2021
Principal Transaction Revenue [Line Items]
AUM subject to variable rate fees	247,707,871
Unearned variable rate fees	4,062,773
Total
Principal Transaction Revenue [Line Items]
AUM subject to variable rate fees	290,323,083
Unearned variable rate fees	$ 4,637,316

Significant Accounting Polici_6

Significant Accounting Policies - Mutual Fund Administration Revenue (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from External Customer [Line Items]
Total revenue	$ 145,627,748	$ 145,201,729	$ 136,103,075
Administration revenue, gross
Revenue from External Customer [Line Items]
Total revenue	24,463,538	26,219,881	26,664,635
12b-1/Service Fees And Commissions
Revenue from External Customer [Line Items]
Total revenue	0	0	6,360,400
Expenses	0	0	(5,660,430)
Fund related expense
Revenue from External Customer [Line Items]
Expenses	(14,183,370)	(13,748,445)	(12,937,067)
Revenue, net of related expenses
Revenue from External Customer [Line Items]
Total revenue	10,280,168	12,471,436	14,427,538
Broker Commission
Revenue from External Customer [Line Items]
Total revenue	332,680	416,614	691,228
Expenses	(302,905)	(374,783)	(660,840)
Financing activity, net
Revenue from External Customer [Line Items]
Total revenue	29,775	41,831	30,388
Mutual fund administration revenue, net
Revenue from External Customer [Line Items]
Total revenue	$ 10,309,943	$ 12,513,267	$ 14,457,926

Significant Accounting Polici_7

Significant Accounting Policies - Textual (Details)	12 Months Ended
	Dec. 31, 2018USD ($)Segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 01, 2019USD ($)	Jan. 01, 2016USD ($)
Business Organization And Significant Accounting Policies [Line Items]
Cumulative-effect adjustment from the adoption of ASU 2015-02 (Note 2)					$ 4,031,756
Number of business segment | Segment	1
Allowance for doubtful accounts	$ 0	$ 0
Accounts receivable, related parties	9,400,000	11,600,000
Accumulated depreciation	$ 5,200,000	4,000,000
Client performance period	5 years
Revenue	$ 145,627,748	145,201,729	$ 136,103,075
Advance commissions amortization period	12 months
Variable rate fees
Business Organization And Significant Accounting Policies [Line Items]
Revenue	$ 1,400,000	200,000	6,400,000
Mutual fund administration revenue, net
Business Organization And Significant Accounting Policies [Line Items]
Revenue	10,309,943	12,513,267	14,457,926
Mutual fund administration revenue, net | Affiliated Entity
Business Organization And Significant Accounting Policies [Line Items]
Revenue from related parties	$ 10,300,000	$ 12,500,000	$ 11,900,000
Accounting Standards Update 2015-02
Business Organization And Significant Accounting Policies [Line Items]
Cumulative-effect adjustment from the adoption of ASU 2015-02 (Note 2)					$ 4,000,000
Accounting Standards Update 2016-02 | Scenario, Forecast
Business Organization And Significant Accounting Policies [Line Items]
Right-of-use asset, operating leases				$ 3,600,000
Lease liability, operating leases				$ 3,600,000

Investments - Summary of Marke

Investments - Summary of Market Value of Investments (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Investment Holdings [Line Items]
Company sponsored equity method investments	$ 16,339,649	$ 36,043,704
Total Investments	203,488,217	138,476,022
Securities held in Consolidated Funds
Investment Holdings [Line Items]
Fair value investments	153,730,480	65,890,500
Company sponsored investments
Investment Holdings [Line Items]
Fair value investments	$ 33,418,088	$ 36,541,818

Investments - Equity Method In

Investments - Equity Method Investments (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Total assets	$ 80,845,124	$ 144,118,745
Total liabilities	22,287,437	38,009,765
Net assets	58,557,687	106,108,980
DHCM's portion of net assets	16,339,649	36,043,704
Investment income	1,154,007	2,944,836	$ 3,272,972
Expenses	978,322	1,176,896	1,409,896
Net realized gains	1,918,661	4,432,850	1,981,185
Net change in unrealized appreciation (depreciation)	(10,229,319)	5,613,627	10,458,073
Net income	(8,134,973)	11,814,417	14,302,334
DHCM’s portion of net income	$ (2,400,467)	$ 3,206,702	$ 4,392,636

Investments - Textual (Details

Investments - Textual (Details) - Securities held in Consolidated Funds - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Debt and Equity Securities, FV-NI [Line Items]
Trading Investments	$ 153,730,480	$ 65,890,500
Parent
Debt and Equity Securities, FV-NI [Line Items]
Trading Investments	84,700,000	42,600,000
Redeemable Noncontrolling Interest
Debt and Equity Securities, FV-NI [Line Items]
Trading Investments	$ 69,000,000	$ 23,300,000

Investments - Equity Investmen

Investments - Equity Investment Ownership (Details)	Dec. 31, 2018	Dec. 31, 2017
Research Opportunities Fund
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	28.00%	26.00%
High Yield Fund
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		48.00%
Global Fund LP
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		95.00%
International Equity Fund LP
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	30.00%	30.00%

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Investment Values Based Upon Fair Value Hierarchy (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 80,690,647	$ 72,669,083
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	80,690,647	72,669,083
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Securities held in Consolidated Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	153,730,480	65,890,500
Securities held in Consolidated Funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	43,595,438	24,618,578
Securities held in Consolidated Funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	110,135,042	41,271,922
Securities held in Consolidated Funds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	0	0
Company sponsored investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	33,418,088	36,541,818
Company sponsored investments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	33,418,088	36,541,818
Company sponsored investments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	0	0
Company sponsored investments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	$ 0	$ 0

Fair Value Measurements - Textu

Fair Value Measurements - Textual (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 80,690,647	$ 72,669,083
Securities held in Consolidated Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	153,730,480	65,890,500
Parent | Securities held in Consolidated Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	84,700,000	42,600,000
Redeemable Noncontrolling Interest | Securities held in Consolidated Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	69,000,000	23,300,000
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	80,690,647	72,669,083
Level 1 | Securities held in Consolidated Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments	43,595,438	24,618,578
Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 80,700,000	$ 72,700,000

Capital Stock (Details)

Capital Stock (Details) - shares	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Compensation Plans - Roll Forw

Compensation Plans - Roll Forward of Restricted Stock Grants (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Shares
Outstanding shares, Beginning Balance (in shares)	191,900
Outstanding shares, Ending Balance (in shares)	211,575	191,900
Restricted Stock Units (RSUs)
Shares
Outstanding shares, Beginning Balance (in shares)	197,900	223,800
Grants issued (in shares)	70,025	41,350
Grants vested (in shares)	(32,450)	(65,500)
Grants forfeited (in shares)	(20,900)	(1,750)
Outstanding shares, Ending Balance (in shares)	214,575	197,900
Weighted-Average Grant Date Price per Share
Beginning of the period (in dollars per share)	$ 165.60	$ 132.96
Grants issued (in dollars per share)	195	204.46
Grants vested (in dollars per share)	82.30	98.81
Grants forfeited (in dollars per share)	196.97	100.73
End of the period (in dollars per share)	$ 177.22	$ 165.60

Compensation Plans - Summary o

Compensation Plans - Summary of Deferred Compensation Expense Recognition (Details) - Restricted Stock Units (RSUs)	Dec. 31, 2018USD ($)
Expense recognition of deferred compensation
2,019	$ 7,135,131
2,020	5,671,192
2,021	4,358,633
2,022	3,371,500
2,023	1,129,611
Thereafter	341,987
Total	$ 22,008,054

Compensation Plans - Schedule

Compensation Plans - Schedule of Grants Issued and Grant Date Fair Value (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Grant Date Value	$ 4,109,197	$ 3,892,424	$ 3,879,431
Common Stock
Shares Issued	20,153	19,219	21,940
Grant Date Value	$ 4,109,197	$ 3,892,424	$ 3,879,431

Compensation Plans - 401(k) Pl

Compensation Plans - 401(k) Plan (Details) - 401K - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock related to 401k plan match (in shares)	11,967	8,478	9,466
Expenses attributable to the 401(k) Plan	$ 2,231,735	$ 1,710,785	$ 1,738,287

Compensation Plans - Textual (

Compensation Plans - Textual (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred compensation equity		$ 22,008,054	$ 22,008,054	$ 19,134,963
Deferred compensation liability, current and noncurrent		$ 22,387,874	$ 22,387,874	$ 20,480,790
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred compensation arrangement, fully vested employee elected deferral period			5 years
401K
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of match	200.00%	250.00%
Employee's compensation contributed to the plan	6.00%	6.00%
Number of years of employment required to vest in contribution			6 years
2011 Equity and Cash Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorizes the issuance of Common Shares in various forms of equity awards (in shares)		600,000	600,000
Common Shares available for awards (in shares)		287,354	287,354

Operating Leases - Textual (De

Operating Leases - Textual (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)ft²Location	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Leases [Abstract]
Lessee leasing agreements, operating leases, area under lease (in sqft) | ft²	37,829
Number of office space locations | Location	1
Operating lease expense excluding rent | $	$ 0.4	$ 0.4	$ 0.4

Operating Leases - Summary of

Operating Leases - Summary of Lease and Operating Expenses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of total lease and operating expense
Lease and operating expenses	$ 970,143	$ 936,008	$ 882,231

Operating Leases - Schedule of

Operating Leases - Schedule of Future Minimum Lease Payments (Details)	Dec. 31, 2018USD ($)
Future minimum lease payments under the operating leases
Total	$ 3,853,831
2,019	586,350
2,020	614,721
2,021	624,179
2,022	624,179
2,023	624,179
Thereafter	$ 780,223

Income Taxes - Summary of Cons

Income Taxes - Summary of Consolidated Provision for Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of consolidated Federal income tax return
Current federal income tax provision	$ 15,731,258	$ 24,749,832	$ 24,234,050
Current state and local income tax provision	8,560,479	1,774,395	1,964,273
Deferred income tax expense (benefit)	(5,622,396)	2,893,063	469,312
Provision for income taxes	$ 18,669,341	$ 29,417,290	$ 26,667,635

Income Taxes - Reconciliation

Income Taxes - Reconciliation of Income Tax Expense to Federal Statutory Rate (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of reconciliation of income tax expense
Income tax computed at statutory rate	$ 13,646,583	$ 28,356,636	$ 25,641,618
Expense (benefit) attributable to redeemable noncontrolling interests	222,624	(564,449)	(189,773)
State and local income taxes, net of federal benefit	2,993,730	1,153,357	1,276,777
Change in uncertain state and local tax positions, net of federal benefit	2,982,337	0	0
Revaluation adjustment of net deferred tax assets	(917,288)	3,557,039	0
Excess tax benefits on vesting of Restricted Stock	(667,697)	(2,420,250)	0
Income tax benefit from dividends paid on Restricted Stock	(340,200)	(418,583)	0
Interest and Penalties	786,711	0	15,748
Other	(37,459)	(246,460)	(76,735)
Provision for income taxes	$ 18,669,341	$ 29,417,290	$ 26,667,635

Income Taxes - Schedule of Def

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Summary of Deferred tax assets and liabilities
Stock-based compensation	$ 4,025,255	$ 2,868,719
Accrued compensation	6,684,531	5,795,204
Unrealized losses	1,323,181
Unrealized (gains)		(2,260,673)
Property and equipment	(498,271)	(467,127)
Other assets and liabilities	(68,596)	(92,419)
Net deferred tax assets	$ 11,466,100	$ 5,843,704

Income Taxes - Roll Forward of

Income Taxes - Roll Forward of Uncertain Tax Positions (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Uncertain tax positions, beginning of the year	$ 0	$ 0	$ 0
Gross addition for tax positions of the current year	0	0	0
Gross additions for tax positions of prior years	2,982,337	0	0
Uncertain tax positions, end of year	$ 2,982,337	$ 0	$ 0

Income Taxes - Textual (Detail

Income Taxes - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Remeasurement of net deferred tax assets - expense (benefit)	$ (917,288)	$ 3,557,039	$ 0
Deferred tax assets, valuation allowance	0
Income tax benefit to shareholders equity			6,300,000
Uncertain tax positions	2,982,337	0	0	$ 0
Interest and penalties expense	$ 786,711	$ 0	$ 15,748

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Computation for earnings per share
Net Income	$ 46,314,388	$ 51,601,669	$ 46,594,132
Less: Net loss (income) attributable to redeemable noncontrolling interest	1,061,441	(1,612,712)	(542,209)
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 47,375,829	$ 49,988,957	$ 46,051,923
Weighted average number of outstanding shares
Weighted average number of outstanding shares (in shares)	3,512,470	3,448,824	3,407,408
Dilutive impact of restricted stock units (in shares)	2,058	3,014	5,983
Weighted average number of outstanding shares - Diluted (in shares)	3,514,528	3,451,838	3,413,391
Earnings per share attributable to common shareholders
Basic (in dollars per share)	$ 13.49	$ 14.49	$ 13.52
Diluted (in dollars per share)	$ 13.48	$ 14.48	$ 13.49

Sale of Beacon Hill (Details)

Sale of Beacon Hill (Details) - USD ($)	Jun. 15, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration received net of cash disposed		$ 500,000	$ 1,000,000	$ 1,163,769
Gain on sale of subsidiary		0	0	2,675,766
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Beacon Hill
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration received net of cash disposed	$ 1,200,000
Gain on sale of subsidiary				$ 2,700,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Beacon Hill | Promissory Note
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent consideration received	$ 1,500,000
Proceeds from collection of notes receivable		$ 500,000	$ 1,000,000