Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues
Investment banking	$ 304,834	$ 105,028
Brokerage	173,737	141,377
Securities principal transactions, net	63,965	(31,045)
Portfolio fund principal transactions, net	15,403	(2,818)
Carried interest allocations	96,769	(11,544)
Gross Investment Income, Operating	176,137	(45,407)
Management fees	25,742	11,604
Incentive income	2,258	0
Interest and dividends	59,388	42,077
Reimbursement from affiliates	288	261
Insurance and reinsurance premiums	7,117	10,471
Other revenues	8,169	1,321
Consolidated Funds
Principal transactions, net, Consolidated Funds	(3,349)	(73,143)
Interest and dividends	2	2,525
Other revenues	0	609
Total revenues	754,323	196,723
Interest and dividends expense	57,641	38,792
Total net revenues	696,682	157,931
Expenses
Employee compensation and benefits	388,196	124,428
Brokerage and trade execution costs	45,656	32,886
Underwriting expenses	6,915	3,640
Professional, advisory and other fees	15,460	11,039
Service fees	5,731	6,837
Communications	9,267	8,176
Occupancy and equipment	9,540	9,530
Depreciation and amortization	4,354	5,442
Client services and business development	6,848	11,803
Insurance and reinsurance claims, commissions and amortization of deferred acquisition costs	6,455	10,430
Other expenses	3,457	4,228
Consolidated Funds
Interest and dividends	0	1,252
Professional, advisory and other fees	110	990
Brokerage and trade execution costs	0	20
Other expenses	161	452
Total expenses	502,150	231,153
Other income (loss)
Net gains (losses) on other investments	12,645	(62)
Bargain Purchase Gain, net of tax	3,855	0
Gain/(loss) on debt extinguishment	(4,538)	0
Total other income (loss)	11,962	(62)
Income (loss) before income taxes	206,494	(73,284)
Income tax expense (benefit)	54,428	(1,173)
Net income (loss)	152,066	(72,111)
Net income (loss) attributable to non-controlling interests in consolidated subsidiaries and investment funds	4,562	(62,188)
Net income (loss) attributable to Cowen Inc.	147,504	(9,923)
Preferred stock dividends	1,698	1,698
Net income (loss) attributable to Cowen Inc. common stockholders	$ 145,806	$ (11,621)
Weighted average common shares outstanding:
Basic (in shares)	27,359	28,598
Diluted (in shares)	33,565	28,598
Earnings (loss) per share:
Earnings Per Share, Basic (in dollars per share)	$ 5.33	$ (0.41)
Earnings Per Share, Diluted (in dollars per share)	$ 4.34	$ (0.41)