Investments in Merchant Banking Funds - Carrying Value of Investments in Merchant Banking Funds (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Investments in and Advances to Affiliates [Line Items]
Investments in merchant banking funds	$ 3,577	$ 3,575
GCP I
Investments in and Advances to Affiliates [Line Items]
Investments in merchant banking funds	1,105	1,105
GCP II
Investments in and Advances to Affiliates [Line Items]
Investments in merchant banking funds	787	785
Investment in Barrow Street
Investments in and Advances to Affiliates [Line Items]
Investments in merchant banking funds	$ 1,685	$ 1,685

Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant