Earnings / (Loss) Per Common Share (Schedule of Earnings / (Loss) Per Common Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Line Items]
Net income / (loss) attributable to Cohen & Company	$ (2,054)	$ (2,463)	$ 2,064
Add/ (deduct): Income / (loss) attributable to non-controlling interest attributable to Operating LLC membership	(1,231)	(1,524)	371
Add: Interest exepse incurred on dilutive convertible notes			1,154
Add / (deduct): Adjustment	246	390	550
Net income / (loss) on a fully converted basis	$ (3,039)	$ (3,597)	$ 4,139
Weighted average common shares outstanding - Basic	1,136,574	1,152,073	1,206,906
Unrestricted Operating LLC membership units exchangeable into Cohen & Company shares	544,599	532,409	532,409
Restricted units or shares			13,858
Weighted average common shares outstanding - Diluted	1,681,173	1,684,482	2,592,254
Net income / (loss) per common share - Basic	$ (1.81)	$ (2.14)	$ 1.71
Net income / (loss) per common share - Diluted	$ (1.81)	$ (2.14)	$ 1.60
8.00% Contingent Convertible Senior Notes Due 2022 [Member]
Earnings Per Share [Line Items]
Number of shares issuable upon conversion of each unit			839,081