Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues
Investment banking	$ 1,067,162	$ 769,486	$ 375,025
Brokerage	585,162	524,361	389,047
Securities principal transactions, net	122,110	124,667	39,289
Portfolio fund principal transactions, net	338	20,434	12,060
Carried interest allocations	5,059	59,250	18,505
Gross Investment Income, Operating	127,507	204,351	69,854
Management fees	72,287	47,515	32,608
Incentive income	2,732	592	1,547
Interest and dividends	219,292	187,459	174,913
Insurance and reinsurance premiums	39,631	30,147	46,335
Other revenues	5,211	10,503	6,069
Consolidated Funds
Principal transactions, net, Consolidated Funds	(6,194)	(24,338)	58,381
Interest and dividends	9	5,218	9,772
Other revenues	0	632	19
Total revenues	2,112,799	1,755,926	1,163,570
Interest and dividends expense	211,387	187,725	168,628
Total net revenues	1,901,412	1,568,201	994,942
Expenses
Employee compensation and benefits	1,046,371	860,531	535,772
Brokerage and trade execution costs	153,831	139,034	103,235
Underwriting expenses	24,978	22,565	15,067
Professional, advisory and other fees	80,849	59,990	48,385
Service fees	25,768	25,378	23,707
Communications	37,499	32,593	31,894
Occupancy and equipment	40,692	36,559	39,726
Depreciation and amortization	19,004	22,677	20,460
Client services and business development	29,607	20,526	50,371
Goodwill Impairment	0	0	4,100
Insurance and reinsurance claims, commissions and amortization of deferred acquisition costs	33,938	33,905	44,070
Other expenses	37,026	33,195	23,114
Consolidated Funds
Interest and dividends	0	2,064	4,602
Professional, advisory and other fees	273	2,087	2,426
Brokerage and trade execution costs	0	37	122
Other expenses	357	1,221	1,813
Total expenses	1,530,193	1,292,362	948,864
Other income (loss)
Net gain (losses) on other investments	35,494	18,879	24,645
Bargain Purchase Gain, net of tax	3,855	0	0
Gain/(loss) on debt extinguishment	(4,538)	2,719	0
Total other income (loss)	34,811	21,598	24,645
Income (loss) before income taxes	406,030	297,437	70,723
Income tax expense (benefit)	102,039	90,373	14,853
Net income (loss)	303,991	207,064	55,870
Net income (loss) attributable to non-controlling interests in consolidated subsidiaries and investment funds	8,380	(9,299)	31,239
Net income (loss) attributable to Cowen Inc.	295,611	216,363	24,631
Preferred stock dividends	6,792	6,792	6,792
Net income (loss) attributable to Cowen Inc. common stockholders	$ 288,819	$ 209,571	$ 17,839
Weighted average common shares outstanding:
Basic (in shares)	27,721	27,790	29,525
Diluted (in shares)	32,628	29,519	31,286
Earnings (loss) per share:
Earnings Per Share, Basic (in dollars per share)	$ 10.42	$ 7.54	$ 0.60
Earnings Per Share, Diluted (in dollars per share)	$ 8.85	$ 7.10	$ 0.57