Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Fees receivable, net of allowance	$ 54,107		$ 54,107		$ 46,498
Redeemable non-controlling interests, Related Party	(171,245)		(171,245)		(86,076)
Net income (loss) attributable to redeemable non-controlling interests, Related Party	(4,344)	$ (4,006)	(10,980)	$ (13,409)
June 29, 2015 | Real Estate Equity Investment
Related Party Transaction [Line Items]
Interest Income, Related Party	300		300
Real estate loan	15,000		$ 15,000
Effective interest rate			8.82%
July 29, 2015 | Real Estate Equity Investment
Related Party Transaction [Line Items]
Real estate loan	900		$ 900
Effective interest rate			6.00%
Employees
Related Party Transaction [Line Items]
Redeemable non-controlling interests, Related Party	25,000		$ 25,000		15,000
Net income (loss) attributable to redeemable non-controlling interests, Related Party	(5,500)	(3,200)	$ (10,300)	(10,100)
Minimum | Employee Loans
Related Party Transaction [Line Items]
Forgivable Loans, Vesting Period			1 year
Maximum | Employee Loans
Related Party Transaction [Line Items]
Forgivable Loans, Vesting Period			3 years
Affiliated Entity
Related Party Transaction [Line Items]
Fees receivable, net of allowance	5,400		$ 5,400		5,100
Affiliated Entity | Fees Payable
Related Party Transaction [Line Items]
Fees payable to related parties	100		100		100
Affiliated Entity | Management Fee and Incentive Income
Related Party Transaction [Line Items]
Reimbursement to affiliated funds				800
Employees
Related Party Transaction [Line Items]
Due from employees	3,800		3,800		6,100
Forgivable Loan Balances	1,700		1,700		3,900
Amortization on Forgivable Loans	600	$ 1,300	2,600	$ 3,200
Investor
Related Party Transaction [Line Items]
Due to Affiliate	$ 300		$ 300		$ 500