Consolidated Statements of Financial Condition - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents		$ 260,994	$ 259,148
Cash collateral pledged		18,609	6,318
Segregated cash		128,782	176,647
Securities owned, at fair value		922,164	520,888
Receivable on derivative contracts, at fair value		39,754	25,125
Securities borrowed		1,228,036	407,795
Other investments ($131,740 and $123,241 at fair value, respectively)		204,168	181,407
Deposits with clearing organizations, brokers and banks		91,450	89,423
Receivable from brokers, dealers and clearing organizations, net of allowance of $719 and $472, respectively		717,634	786,113
Receivable from customers, net of allowance of $623 and $516, respectively		46,126	37,858
Fees receivable, net of allowance of $1,399 and $1,569, respectively		101,508	111,946
Due from related parties		27,849	33,870
Fixed assets, net of accumulated depreciation and amortization of $31,007 and $31,630, respectively		29,977	26,443
Operating right of use assets		96,664	0
Goodwill		137,728	60,678
Intangible assets, net of accumulated amortization of $47,878 and $38,093, respectively		37,358	24,943
Deferred tax asset, net		84,041	93,057
Other assets		76,916	79,014
Consolidated Funds
Cash and cash equivalents, Consolidated Funds		3,364	38,118
Securities owned, at fair value		369,191	187,633
Receivable on derivative contracts, at fair value		3,885	4,416
Other Investments, Consolidated Funds		171,186	186,395
Receivable from brokers, Consolidated Funds		17,907	8,328
Other assets, Consolidated Funds		1,463	740
Total Assets		4,816,754	3,346,303
Liabilities
Securities sold, not yet purchased, at fair value		364,742	195,307
Securities Sold under Agreements to Repurchase		23,772	0
Payable for derivative contracts, at fair value		32,755	16,082
Securities Loaned		1,339,647	414,852
Payables to brokers, dealers and clearing organizations		271,012	228,731
Payable to customers		525,064	525,153
Commission management payable		89,124	95,270
Compensation payable		157,125	226,971
Operating lease liabilities		100,934	0
Notes payable and other debt		343,286	262,965
Convertible debt	[1]	117,469	134,489
Fees payable		33,625	22,565
Due to related parties		919	571
Accounts payable, accrued expenses and other liabilities		142,026	110,423
Consolidated Funds
Due to related parties		615	0
Payable for derivative contracts, at fair value		7,778	1,663
Payable to brokers		15,166	23,521
Capital withdrawals payable		1,002	11,106
Accounts payable, accrued expenses and other liabilities		455	424
Total Liabilities		3,566,516	2,270,093
Commitments and Contingencies
Commitments and Contingencies (Note 17)		348,424	216,923
Stockholders' equity
Additional paid-in capital		1,103,941	1,062,877
(Accumulated deficit) retained earnings		(20,334)	(34,648)
Accumulated other comprehensive income (loss)		(5)	(5)
Less: Class A common stock held in treasury, at cost, 16,664,613 and 15,336,871 shares as of June 30, 2019 and December 31, 2018, respectively.		(266,882)	(234,142)
Total Cowen Inc. Stockholders' Equity		901,814	859,287
Nonredeemable non-controlling interests		84,759	64,880
Total Permanent Equity		817,055	794,407
Total Liabilities and Stockholders' Equity		4,816,754	3,346,303
Convertible Preferred Stock
Stockholders' equity
Preferred stock		1	1
Common Stock Class A
Stockholders' equity
Common stock		334	324
Less: Class A common stock held in treasury, at cost, 16,664,613 and 15,336,871 shares as of June 30, 2019 and December 31, 2018, respectively.		(266,882)	(234,142)
Total Cowen Inc. Stockholders' Equity		901,814	859,287
Common Stock Class B
Stockholders' equity
Common stock		$ 0	$ 0

[1] The carrying amount of the convertible debt includes an unamortized discount of $16.0 million and $19.5 million as of September 30, 2019 and December 31, 2018, respectively.