Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 65,855	$ 303,991	$ 207,064
Other comprehensive income (loss), net of tax:
Foreign currency translation	3	5	(2)
Total other comprehensive income (loss), net of tax	3	5	(2)
Comprehensive income (loss)	65,858	303,996	207,062
Less: Comprehensive income (loss) attributable to non-controlling interests	(10,603)	8,380	(9,299)
Comprehensive income (loss) attributable to Cowen Inc.	$ 76,461	$ 295,616	$ 216,361