Related Party Transactions (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Due from affiliates:
Loans	$ 33,963		$ 23,888
Amounts due from non-consolidated funds	1,183		1,014
Payments made on behalf of non-consolidated entities	6,992		4,091
Non-interest bearing advances made to certain non-controlling interest holders and employees	2,178		2,833
Total due from affiliates	44,316		31,826
Due to affiliates:
Due to OCGH Unitholders in connection with the tax receivable agreement (please see note 11)	138,307		56,787
Amounts due to principals, certain non-controlling interest holders and employees	1,932		787
Total due to affiliates	140,239		57,574
Amounts Due from and Due to Affiliates (Textual) [Abstract]
Interest income	$ 609	$ 472