Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Investment banking		$ 133,279	$ 222,781	$ 170,506
Brokerage		199,180	157,722	140,132
Management fees		40,612	41,906	40,627
Incentive income		8,334	1,466	2,785
Interest and dividends		14,732	13,796	48,870
Reimbursement from affiliates		10,504	21,557	12,495
Aircraft lease revenue		4,161	0	0
Reinsurance premiums		32,459	0	0
Other revenue		22,355	3,726	9,446
Consolidated Funds
Interest and dividends		4,792	1,086	2,189
Other revenues		1,157	527	726
Total revenues		471,565	464,567	427,776
Expenses
Employee compensation and benefits		310,038	321,386	305,483
Floor brokerage and trade execution		32,286	27,460	23,425
Interest and dividends		29,308	26,220	42,752
Professional, advisory and other fees		23,190	25,578	18,724
Service fees		7,918	7,535	8,071
Communications		17,768	14,325	13,449
Occupancy and equipment		32,286	29,055	26,025
Depreciation and amortization		12,713	9,498	10,188
Client services and business development		27,828	25,413	22,897
Goodwill Impairment		0	0	2,334
Reinsurance claims, commissions and amortization of deferred acquisition costs		29,904	0	0
Other Expenses		14,815	15,594	15,209
Consolidated Funds
Interest and dividends		6,434	1,104	788
Professional, advisory and other fees		1,148	654	620
Floor brokerage and trade execution		431	51	16
Other expenses		1,051	501	210
Total expenses		547,118	504,374	490,191
Other income (loss)
Net gains (losses) on securities, derivatives and other investments		23,381	36,789	104,928
Consolidated Funds
Net realized and unrealized gains (losses) on investments and other transactions		7,085	12,517	12,890
Net realized and unrealized gains (losses) on derivatives		13,503	2,071	2,451
Net gains (losses) on foreign currency transactions		97	(91)	(18)
Total other income (loss)		44,066	51,286	120,251
Income (loss) before income taxes		(31,487)	11,479	57,836
Income tax expense (benefit)		(19,092)	(47,496)	(124,944)
Net income (loss)		(12,395)	58,975	182,780
Net income (loss) attributable to redeemable non-controlling interests in consolidated subsidiaries and funds		(6,882)	(15,246)	(15,564)
Net income (loss) attributable to Cowen Group, Inc.		(19,277)	43,729	167,216
Preferred stock dividends		6,792	4,075	0
Net income (loss) attributable to Cowen Group, Inc. common stockholders		$ (26,069)	$ 39,654	$ 167,216
Weighted average common shares outstanding:
Basic (in shares)	[1]	26,857	27,522	28,731	[2]
Diluted (in shares)	[1],[2]	26,857	29,043	29,871
Earnings (loss) per share:
Earnings Per Share, Basic (in dollars per share)	[1],[2]	$ (0.97)	$ 1.44	$ 5.82
Earnings Per Share, Diluted (in dollars per share)	[1],[2]	$ (0.97)	$ 1.37	$ 5.60

[1] Share and per share amounts have been retroactively updated to reflect the one-for-four reverse stock split effective as of December 5, 2016.

[2] Share and per share amounts have been retroactively updated to reflect the one-for-four reverse stock split effective as of December 5, 2016.