Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Fees receivable, net of allowance	$ 34,413				$ 46,498				$ 34,413	$ 46,498
Redeemable non-controlling interests, Related Party	(186,911)				(86,076)				(186,911)	(86,076)
Net income (loss) attributable to redeemable non-controlling interests, Related Party	(4,266)	$ (4,344)	$ (3,916)	$ (2,720)	(2,155)	$ (4,006)	$ (5,216)	$ (4,187)	(15,246)	(15,564)	$ (13,193)
June 29, 2015 | Real Estate Equity Investment
Related Party Transaction [Line Items]
Interest Income, Related Party									300
Real estate loan	15,000								$ 15,000
Effective interest rate									8.82%
Employees
Related Party Transaction [Line Items]
Redeemable non-controlling interests, Related Party	21,300				15,100				$ 21,300	15,100
Net income (loss) attributable to redeemable non-controlling interests, Related Party									$ (10,400)	(10,600)
Employee Loans | Minimum
Related Party Transaction [Line Items]
Forgivable Loans, Vesting Period									1 year
Employee Loans | Maximum
Related Party Transaction [Line Items]
Forgivable Loans, Vesting Period									3 years
Affiliated Entity
Related Party Transaction [Line Items]
Fees receivable, net of allowance	6,300				5,100				$ 6,300	5,100
Affiliated Entity | Fees Payable
Related Party Transaction [Line Items]
Fees payable to related parties	100				100				100	100
Affiliated Entity | Management Fee and Incentive Income
Related Party Transaction [Line Items]
Reimbursement to affiliated funds										700	1,700
Employees
Related Party Transaction [Line Items]
Due from employees	5,500				6,100				5,500	6,100
Forgivable Loan Balances	1,200				3,900				1,200	3,900
Amortization on Forgivable Loans									3,200	4,400	$ 3,200
Investor
Related Party Transaction [Line Items]
Due to Affiliate	$ 300				$ 500				$ 300	$ 500