Schedule I And Quarterly Info Part II (Selected Quarterly Financial Results) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Total revenues	$ 15,621	$ 12,237	$ 12,190	$ 9,338	$ 11,675	$ 10,001	$ 11,374	$ 14,492	$ 49,386		$ 47,542		$ 55,348
Compensation and benefits	6,425	7,177	6,589	5,194	5,034	4,759	5,549	7,185	25,385		22,527		31,132
Business development, occupancy, equipment	759	725	644	867	702	738	697	586	2,995		2,723		2,595
Subscriptions, clearing, and execution	2,209	2,433	2,151	1,834	2,127	1,789	1,667	1,713	8,627		7,296		6,425
Professional fee and other operating	3,855	1,483	1,379	1,742	1,651	1,666	1,674	2,354	8,459		7,345		6,319
Depreciation and amortization	85	63	52	61	62	60	61	66	261		249		291
Total operating expenses	13,333	11,881	10,815	9,698	9,576	9,012	9,648	11,904	45,727		40,140		46,762
Operating income (loss)	2,288	356	1,375	(360)	2,099	989	1,726	2,588	3,659		7,402		8,586
Interest expense, net	(2,282)	(2,185)	(2,201)	(1,819)	(1,848)	(1,606)	(1,112)	(1,612)	(8,487)		(6,178)		(4,735)
Income (loss) before income tax expense (benefit)	6	(1,829)	(826)	(2,179)	251	(617)	614	976	(4,828)		1,224		3,851
Income tax expense (benefit)	418	(595)	(636)	(28)	(1,359)	141	2	5	(841)		(1,211)		422
Net income (loss)	(412)	(1,234)	(190)	(2,151)	1,610	(758)	612	971	(3,987)		2,435		3,429
Less: comprehensive income (loss) attributable to the non-controlling interest	6	(583)	(270)	(677)	97	(211)	186	299	(1,562)		461		1,076
Net income (loss) attributable to Cohen & Company Inc.	$ (418)	$ (651)	$ 80	$ (1,474)	$ 1,513	$ (547)	$ 426	$ 672	$ (2,463)		$ 2,064		$ 2,267
Basic income (loss) per common share	$ (0.37)	$ (0.57)	$ 0.07	$ (1.26)	$ 1.26	$ (0.45)	$ 0.35	$ 0.56	$ (2.14)		$ 1.71		$ 1.86
Weighted average shares outstanding-basic	1,117,576	1,145,323	1,172,919	1,172,476	1,198,869	1,212,826	1,216,692	1,199,238	1,152,073		1,206,906		1,219,189
Diluted income (loss) per common share	$ (0.37)	$ (0.57)	$ 0.07	$ (1.26)	$ 0.90	$ (0.45)	$ 0.35	$ 0.52	$ (2.14)		$ 1.60		$ 1.85
Weighted average shares outstanding-diluted	1,649,985	1,677,732	1,719,671	1,704,885	3,054,293	1,745,235	2,791,381	2,004,479	1,684,482	[1]	2,592,254	[1]	1,763,002	[1]
Cohen & Company [Member]
Total revenues									$ 921		$ 4,939		$ 6,610
Operating income (loss)									921		4,939		6,610
Interest expense, net									(4,251)		(4,104)		(3,973)
Income (loss) before income tax expense (benefit)									(3,330)		835		2,637
Income tax expense (benefit)									(867)		(1,229)		370
Net income (loss)									(2,463)		2,064		2,267
Net income (loss) attributable to Cohen & Company Inc.									$ (2,463)		$ 2,064		$ 2,267

[1] For the year ended December 31, 2018, weighted average common shares outstanding excludes (i) 26,380 shares representing restricted Common Stock (ii) 352,292 shares from the assumed conversion of the 2013 Convertible Notes and (iii) 1,034,483 shares from the assumed conversion of the 2017 Convertible Note because the inclusion of such shares would be anti-dilutive.For the years ended December 31, 2017 and 2016 weighted average common shares outstanding excludes 274,917 shares from the assumed conversion of the 2013 Convertible Notes because the inclusion of such shares would be anti-dilutive.