Equity (Schedule Of Effects Of Changes In Ownership Interest Subsidiary) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Net income (loss) attributable to Cohen & Company Inc.	$ (547)	$ 1,041	$ 551	$ 2,070
Increase / (decrease) in Cohen & Company Inc.'s paid in capital for the acquisition / (surrender) of additional units in consolidated subsidiary, net			153	(552)
Changes from net income / (loss) attributable to Cohen & Company Inc. and transfers (to) from non-controlling interest			$ 704	$ 1,518