Commitments and Contingencies (Details) (USD $)	3 Months Ended		9 Months Ended																9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Affiliated Entity	Sep. 30, 2014 Healthcare Royalty Partners Affiliated Entity	Sep. 30, 2014 Healthcare Royalty Partners Affiliated Entity Minimum	Sep. 30, 2014 Healthcare Royalty Partners Affiliated Entity Maximum	Sep. 30, 2014 Starboard Leaders Fund LP Affiliated Entity	Sep. 30, 2014 Formation 8 Partners Fund I LP Affiliated Entity	Sep. 30, 2014 Equipment Leases		Sep. 30, 2014 Service Payments	Sep. 30, 2014 Facility Leases		Sep. 30, 2014 Clawback Obligation	Dec. 31, 2013 Clawback Obligation	Apr. 30, 2013 Commitment to Invest Starboard Leaders Fund LP Affiliated Entity	Sep. 30, 2014 Commitment to Invest Formation 8 Partners Fund I LP Affiliated Entity	Sep. 30, 2014 Unfunded Commitments cowenfund	Sep. 30, 2014 RCG Longview Partners II, LLC [Member] Clawback Obligation
Lease Obligations
Net rent expense	$ 4,300,000	$ 4,300,000	$ 12,500,000	$ 12,300,000
Future minimum annual lease and service payments
Contractual Obligation, Due in Remainder of Fiscal Year											727,000	[1]	3,970,000	4,829,000	[2]
Contractual Obligation, Due in Second Year											2,603,000	[1]	11,708,000	18,481,000	[2]
Contractual Obligation, Due in Third Year											2,284,000	[1]	6,019,000	15,109,000	[2]
Contractual Obligation, Due in Fourth Year											2,198,000	[1]	3,039,000	11,676,000	[2]
Contractual Obligation, Due in Fifth Year											2,198,000	[1]	2,709,000	11,358,000	[2]
Contractual Obligation, Due after Fifth Year											813,000	[1]	22,000	41,644,000	[2]
Future minimum annual lease and service payments											10,823,000	[1]	27,467,000	103,097,000	[2]
Sublease income related to operating leases	500,000	400,000	1,300,000	1,000,000
Contractual obligation						45,200,000										6,200,000	6,200,000	1,000,000			6,200,000
Number of real estate investments, in investments																				3
Expected call period							2 years	5 years
Funding toward commitments						34,900,000			700,000
Other commitments, unfunded amount					$ 12,100,000					$ 5,500,000
Term of capital commitment																			4 years

[1] Equipment Leases include the Company's commitments relating to operating and capital leases. See Note 14 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 September 30, 2014 and 2013 and $1.3 million and $1.0 million for the nine months ended September 30, 2014 and 2013.