Note 18 - Equity - Schedule of Effects of Changes in Ownership Interest Subsidiary (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net income (loss) attributable to Cohen & Company Inc.	$ 1,725	$ 901	$ 11,080	$ (2,201)
Increase / (decrease) in Cohen & Company, Inc. paid in capital for the acquisition / (surrender) of additional units in consolidated subsidiary, net			2,375	(123)
Changes from net income / (loss) attributable to Cohen & Company Inc. and transfers (to) from the non-controlling interest			$ 13,455	$ (2,324)