Commitments and Contingencies (Details)		3 Months Ended		6 Months Ended
		Jun. 30, 2016 USD ($) cowenfund	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) cowenfund	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Lease Obligations
Net rent expense		$ 5,200,000	$ 4,300,000	$ 10,400,000	$ 8,700,000
Future minimum annual lease and service payments
Sublease income related to operating leases		500,000	$ 400,000	1,300,000	$ 900,000
Lagunita Biosciences LLC [Member]
Future minimum annual lease and service payments
Other commitments, unfunded amount				3,500,000
Affiliated Entity
Future minimum annual lease and service payments
Other commitments, unfunded amount				7,400,000
Affiliated Entity | Healthcare Royalty Partners
Future minimum annual lease and service payments
Contractual obligation		45,800,000		45,800,000
Funding toward commitments				$ 37,700,000
Affiliated Entity | Healthcare Royalty Partners | Minimum
Future minimum annual lease and service payments
Expected call period				2 years
Affiliated Entity | Healthcare Royalty Partners | Maximum
Future minimum annual lease and service payments
Expected call period				5 years
Affiliated Entity | Formation 8 Partners Fund I LP
Future minimum annual lease and service payments
Other commitments, unfunded amount				$ 500,000
Affiliated Entity | Eclipse Ventures Fund I, L.P.
Future minimum annual lease and service payments
Other commitments, unfunded amount				900,000
Clawback Obligation
Future minimum annual lease and service payments
Contractual obligation		$ 6,200,000		$ 6,200,000		$ 6,200,000
Commitment to Invest | Lagunita Biosciences LLC [Member]
Future minimum annual lease and service payments
Term of capital commitment				3 years
Commitment to Invest | Affiliated Entity | Formation 8 Partners Fund I LP
Future minimum annual lease and service payments
Term of capital commitment				1 year
Commitment to Invest | Affiliated Entity | Eclipse Ventures Fund I, L.P.
Future minimum annual lease and service payments
Term of capital commitment				1 year
Unfunded Commitments
Future minimum annual lease and service payments
Number of Real Estate Investments | cowenfund		4		4
RCG Longview Partners II, LLC | Clawback Obligation
Future minimum annual lease and service payments
Contractual obligation		$ 6,200,000		$ 6,200,000		$ 6,200,000
Equipment Leases
Future minimum annual lease and service payments
Contractual Obligation, Due in remainder of current year	[1]	1,213,000		1,213,000
Contractual Obligation, Due in Second Year	[1]	2,320,000		2,320,000
Contractual Obligation, Due in Third Year	[1]	2,239,000		2,239,000
Contractual Obligation, Due in Fourth Year	[1]	826,000		826,000
Contractual Obligation, Due in Fifth Year	[1]	2,000		2,000
Thereafter	[1]	0		0
Future minimum annual lease and service payments	[1]	6,600,000		6,600,000
Service Payments
Future minimum annual lease and service payments
Contractual Obligation, Due in remainder of current year		10,402,000		10,402,000
Contractual Obligation, Due in Second Year		11,158,000		11,158,000
Contractual Obligation, Due in Third Year		5,230,000		5,230,000
Contractual Obligation, Due in Fourth Year		1,430,000		1,430,000
Contractual Obligation, Due in Fifth Year		0		0
Thereafter		0		0
Future minimum annual lease and service payments		28,220,000		28,220,000
Facility Leases
Future minimum annual lease and service payments
Contractual Obligation, Due in remainder of current year	[2]	9,257,000		9,257,000
Contractual Obligation, Due in Second Year	[2]	16,424,000		16,424,000
Contractual Obligation, Due in Third Year	[2]	16,326,000		16,326,000
Contractual Obligation, Due in Fourth Year	[2]	14,939,000		14,939,000
Contractual Obligation, Due in Fifth Year	[2]	14,814,000		14,814,000
Thereafter	[2]	32,250,000		32,250,000
Future minimum annual lease and service payments	[2]	$ 104,010,000		$ 104,010,000

[1] Equipment Leases include the Company's commitments relating to operating and capital leases. See Note 13 for further information on the capital lease minimum payments which are included in the table.

[2] The Company has entered into various agreements to sublease certain of its premises. The Company recorded sublease income related to these leases of $0.5 million and $0.4 million for the three months ended June 30, 2016 and 2015 and $1.3 million and $0.9 million and for the six months ended June 30, 2016 and 2015, respectively.