Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock Common Class A	Common Stock Common Class B	Additional Paid in Capital	Accumulated Deficit	Non-controlling Interests Consolidated Subsidiaries	Non-controlling Interests Medley LLC
Beginning balance (in shares) at Dec. 31, 2018		570,100	10
Beginning balance at Dec. 31, 2018	$ (110,621)	$ 6	$ 0	$ 7,580	$ (19,618)	$ (747)	$ (97,842)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(4,387)				(770)	461	(4,078)
Stock-based compensation	5,227			5,227
Dividends declared on Class A common stock ($0.03 per share)	(238)				(238)
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings (in shares)		27,136
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings	(511)	$ 0		(511)
Distributions	(955)					(223)	(732)
Reclassification of cumulative dividends on forfeited restricted stock units to compensation and benefits expense	336				336
Ending balance at Sep. 30, 2019	(111,149)	$ 6	$ 0	12,296	(20,290)	(509)	(102,652)
Ending balance (in shares) at Sep. 30, 2019		597,236.000	10.00
Beginning balance (in shares) at Jun. 30, 2019		587,081	10
Beginning balance at Jun. 30, 2019	(109,591)	$ 6	$ 0	10,487	(19,812)	(416)	(99,856)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(3,405)				(516)	(93)	(2,796)
Stock-based compensation	2,005			2,005
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings (in shares)		10,155
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings	(196)	$ 0		(196)
Reclassification of cumulative dividends on forfeited restricted stock units to compensation and benefits expense	38				38
Ending balance at Sep. 30, 2019	(111,149)	$ 6	$ 0	12,296	(20,290)	(509)	(102,652)
Ending balance (in shares) at Sep. 30, 2019		597,236.000	10.00
Beginning balance (in shares) at Dec. 31, 2019		620,981	10
Beginning balance at Dec. 31, 2019	(118,085)	$ 6	$ 0	13,835	(22,960)	(391)	(108,575)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(15,790)				(2,066)	64	(13,788)
Stock-based compensation	2,946			2,946
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings (in shares)		48,772
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings	(123)	$ 1		(124)
Distributions	(551)					(150)	(401)
Fair value adjustment to redeemable non-controlling interests (Note 17)	(752)				(145)		(607)
Reclassification of cumulative dividends on forfeited restricted stock units to compensation and benefits expense	375				375
Ending balance at Sep. 30, 2020	(131,980)	$ 7	$ 0	16,657	(24,796)	(477)	(123,371)
Ending balance (in shares) at Sep. 30, 2020		669,753	10
Beginning balance (in shares) at Jun. 30, 2020		637,082	10
Beginning balance at Jun. 30, 2020	(131,356)	$ 6	$ 0	15,473	(24,674)	(364)	(121,797)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1,695)					1	(1,574)
Stock-based compensation	1,208			1,208
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings (in shares)		32,671
Issuance of Class A common stock related to the vesting of restricted stock units, net of tax withholdings	(23)	$ 1		(24)
Distributions	(114)					(114)	0
Ending balance at Sep. 30, 2020	$ (131,980)	$ 7	$ 0	$ 16,657	$ (24,796)	$ (477)	$ (123,371)
Ending balance (in shares) at Sep. 30, 2020		669,753	10