Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues
Investment banking	$ 53,012	$ 45,799	$ 186,763	$ 125,653
Brokerage	41,085	34,334	111,496	100,475
Management fees	10,519	9,796	31,169	28,412
Incentive income	93	(837)	365	4,385
Interest and dividends	3,604	13,725	9,846	35,437
Reimbursement from affiliates	3,355	2,473	10,499	7,391
Other revenue	1,312	1,120	2,684	2,427
Consolidated Funds
Interest and dividends	245	642	685	1,783
Other revenues	29	49	449	717
Total revenues	113,254	107,101	353,956	306,680
Expenses
Employee compensation and benefits	56,401	65,806	227,593	197,771
Floor brokerage and trade execution	6,415	5,125	18,418	16,638
Interest and dividends	7,367	12,429	19,241	29,694
Professional, advisory and other fees	6,392	4,621	16,874	12,596
Service fees	1,778	1,933	5,338	6,161
Communications	3,478	3,286	10,313	9,554
Occupancy and equipment	7,286	6,650	21,024	19,371
Depreciation and amortization	2,301	2,274	6,584	7,036
Client services and business development	5,132	6,577	18,316	16,726
Other expenses	3,783	3,364	11,442	9,750
Consolidated Funds
Interest and dividends	366	218	858	517
Professional, advisory and other fees	174	348	476	622
Floor brokerage and trade execution	(20)	1	46	7
Other expenses	114	68	246	189
Total expenses	100,967	112,700	356,769	326,632
Other income (loss)
Net gains (losses) on securities, derivatives and other investments	(23,612)	13,836	24,449	48,227
Consolidated Funds
Net realized and unrealized gains (losses) on investments and other transactions	333	532	8,073	8,474
Net realized and unrealized gains (losses) on derivatives	(78)	1,899	(404)	1,688
Net gains (losses) on foreign currency transactions	(13)	2	(45)	(17)
Total other income (loss)	(23,370)	16,269	32,073	58,372
Income (loss) before income taxes	(11,083)	10,670	29,260	38,420
Income tax expense (benefit)	(5,081)	141	5,212	266
Net income (loss)	(6,002)	10,529	24,048	38,154
Net income (loss) attributable to redeemable non-controlling interests in consolidated subsidiaries and funds	4,344	4,006	10,980	13,409
Net income (loss) attributable to Cowen Group, Inc.	(10,346)	6,523	13,068	24,745
Preferred Stock Dividends	1,603	0	2,358	0
Net income (loss) attributable to Cowen Group, Inc. common stockholders	$ (11,949)	$ 6,523	$ 10,710	$ 24,745
Weighted average common shares outstanding:
Basic (in shares)	109,191	114,969	111,050	115,407
Diluted (in shares)	109,191	118,801	117,249	120,027
Earnings (loss) per share:
Earnings Per Share, Basic (in dollars per share)	$ (0.11)	$ 0.06	$ 0.10	$ 0.21
Earnings Per Share, Diluted (in dollars per share)	$ (0.11)	$ 0.05	$ 0.09	$ 0.21