Consolidated Statement of Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018		Sep. 30, 2017
Interest and fees on loans			$ 124	$ 64,718	[1]	$ 1,383
Interest income		$ 33,152		3,287	[1]
Medallion lease income	[1]			100
Interest and dividends on investment securities	[1]			1,032
Total interest income/total investment income	[1],[2]			69,829
Interest on deposits	[1]			9,264
Interest on short term borrowings	[1]			3,557
Interest on long term debt	[1]			3,991
Interest expense	[1]			3,551
Total interest expense		8,887		20,363	[1],[3]
Net interest income		24,265		49,466	[1]
Provision for loan losses		18,205		48,781	[1]
Net interest loss after provision for loan losses		6,060		685	[1]
Other income (loss)
Sponsorship and race winnings		5,371		10,599	[1]
Gain on sale of loans	[1]			5,488
Impairment of equity investments	[1]			(862)
Writedown of loan collateral in process of foreclosure	[1]			(1,361)
Other income	[1]			515
Total other income	[1]			14,379
Other expenses
Salaries and employee benefits	[1]			13,987
Race team related expenses		(2,876)		5,416	[1]
Professional fees	[1]			6,920
Loan servicing fees	[1]			2,313
Collection costs	[1]			2,218
Travel, meals and entertainment	[1]			1,122
Rent expense	[1]			1,449
Regulatory fees	[1]			1,145
Amortization of intangible assets	[1]			722
Other expenses	[1],[4]			5,206
Total other expenses	[1]			40,498
Loss before income taxes/net investment loss before taxes		(3,963)		(25,434)	[1],[5]
Income tax benefit (provision)	[1]			4,474
Net loss after taxes/net investment loss after taxes	[1]			(20,960)
Net realized gains (losses) on investments	[1],[6]			(34,745)
Income tax benefit	[1]			8,426
Total net realized gains (losses) on investments	[1]			(26,319)
Net change in unrealized appreciation on Medallion Bank and other controlled subsidiaries	[1]			29,115
Net change in unrealized depreciation on investments other than securities	[1]			(1,915)
Net change in unrealized depreciation on investments	[1]			(4,403)
Income tax (provision) benefit	[1]			(8,122)
Net unrealized appreciation (depreciation) on investments	[1]			14,675
Net realized/unrealized gains (losses) on investments	[1]			(11,644)
Net loss after taxes/net increase (decrease) on net assets resulting from operations		$ (3,846)		(32,604)	[1]
Less: income attributable to the noncontrolling interest	[1]			1,614
Total net income (loss) attributable to Medallion Financial Corp./net increase (decrease) on net assets resulting from operations	[1]			$ (34,218)
Basic net loss per share		$ (0.19)	$ 0.03	$ (1.41)	[1]	$ (0.13)
Diluted net loss per share		$ (0.19)	$ 0.03	(1.41)	[1]	$ (0.13)
Distributions declared per share	[1]			$ 0
Weighted average common shares outstanding
Basic		24,235,242	23,930,086	24,207,273	[1]	23,916,334
Diluted		24,235,242	24,083,919	24,207,273	[1]	23,916,334
Controlled Subsidiary Investment [Member]
Interest income	[1]			$ 10
Dividend income from controlled subsidiaries	[1]			28
Affiliate Investment [Member]
Interest income	[1]			654
Bank Holding Company Accounting [Member]
Interest and fees on loans		$ 32,692
Medallion lease income		30
Interest and dividends on investment securities		430
Total interest income/total investment income	[2]	33,152
Interest on deposits		5,064
Interest on short term borrowings		1,698
Interest on long term debt		2,125
Total interest expense	[3]	8,887
Net interest income		24,265
Provision for loan losses		18,205		48,781
Net interest loss after provision for loan losses		6,060
Other income (loss)
Sponsorship and race winnings		5,371
Gain on sale of loans		5,488
Impairment of equity investments		(388)
Writedown of loan collateral in process of foreclosure		(1,265)
Other income		235
Total other income		9,441
Other expenses
Salaries and employee benefits		5,999
Race team related expenses		2,876
Professional fees		3,951
Loan servicing fees		1,185
Collection costs		1,381
Travel, meals and entertainment		313
Rent expense		615
Regulatory fees		563
Amortization of intangible assets		361		$ 722
Other expenses	[4]	2,220
Total other expenses		19,464
Loss before income taxes/net investment loss before taxes	[5]	(3,963)
Income tax benefit (provision)		117
Net loss after taxes/net investment loss after taxes		(3,846)
Net loss after taxes/net increase (decrease) on net assets resulting from operations		(3,846)
Less: income attributable to the noncontrolling interest		851
Total net income (loss) attributable to Medallion Financial Corp./net increase (decrease) on net assets resulting from operations		$ (4,697)
Basic net loss per share		$ (0.19)
Diluted net loss per share		(0.19)
Distributions declared per share		$ 0
Weighted average common shares outstanding
Basic		24,235,242
Diluted		24,235,242
Investment Company Accounting [Member]
Interest income			$ 3,768			$ 10,153
Medallion lease income			40			159
Dividends and interest income on short-term investments			11			27
Total interest income/total investment income	[2]		5,567			13,604
Interest expense			3,543			10,285
Total interest expense	[3]		3,543			10,285
Net interest income			2,024			3,319
Net interest loss after provision for loan losses			2,024			3,319
Other income (loss)
Other income			8			22
Total other income			8			22
Other expenses
Salaries and employee benefits			2,224			5,086
Professional fees			567			1,875
Collection costs			64			168
Travel, meals and entertainment			126			541
Rent expense			275			802
Other expenses	[4]		420			1,111
Total other expenses			3,676			9,583
Loss before income taxes/net investment loss before taxes	[5]		(1,644)			(6,242)
Income tax benefit (provision)			(846)			2,024
Net loss after taxes/net investment loss after taxes			(2,490)			(4,218)
Net realized gains (losses) on investments	[6]		944			3,785
Total net realized gains (losses) on investments			944			3,785
Net change in unrealized appreciation on Medallion Bank and other controlled subsidiaries			2,035			11,089
Net change in unrealized depreciation on investments			(6,871)			(26,843)
Income tax (provision) benefit			7,001			13,120
Net unrealized appreciation (depreciation) on investments			2,165			(2,634)
Net realized/unrealized gains (losses) on investments			3,109			1,151
Net loss after taxes/net increase (decrease) on net assets resulting from operations			619			(3,067)
Total net income (loss) attributable to Medallion Financial Corp./net increase (decrease) on net assets resulting from operations			$ 619			$ (3,067)
Basic net loss per share			$ 0.03			$ (0.13)
Diluted net loss per share			0.03			(0.13)
Distributions declared per share			$ 0			$ 0
Weighted average common shares outstanding
Basic			23,930,086			23,916,334
Diluted			24,083,919			23,916,334
Investment Company Accounting [Member] | Controlled Subsidiary Investment [Member]
Interest income			$ 39			$ 165
Dividend income from controlled subsidiaries			1,256			1,256
Investment Company Accounting [Member] | Affiliate Investment [Member]
Interest income			$ 453			$ 1,844

[1] Balance includes the six months ended September 30, 2018 under Bank Holding Company Accounting and three months ended March 31, 2018 under Investment Company Accounting.

[2] Included in interest and investment income is $450 and $1,428 of paid in kind interest for the three and nine months ended September 30, 2018 and $939 and $1,650 for the comparable 2017 periods.

[3] Average borrowings outstanding were $1,255,945 and $1,226,896, and the related average borrowing costs were 2.81% and 2.22% for the three and nine months ended September 30, 2018, and were $330,885 and $335,907 and 4.25% and 4.09% for the comparable 2017 periods.

[4] See Note 11 for the components of other operating expenses.

[5] Includes $256 of net revenues received from Medallion Bank for the nine months ended September 30, 2018 and $184 and $641 for the three and nine months ended September 30, 2017, primarily for expense reimbursements. See Notes 6 and 13 for additional information.

[6] There were no net losses on investment securities of affiliated issuers for the nine months ended September 30, 2018 and for the three and nine months ended September 30, 2017.