Fair Value Measurements for Operating Entities and Consolidated Funds Carrying Value Disclosures (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Mar. 10, 2014	Dec. 31, 2013
Cash and cash equivalents		$ 112,014	$ 158,485	$ 129,509		$ 54,720
Cash collateral pledged		13,342	10,085
Loans Receivable, Net		31,088	65,612
Cash and cash equivalents, Consolidated Funds		17,761	13,934
Convertible debt	[1]	130,029	122,401
Notes payable and other debt		77,030	68,565
Convertible Debt
Convertible debt, unamortized discount		17,800	24,700		$ 35,700
Level 1
Cash and cash equivalents, Fair Value		112,014	158,485
Cash and cash equivalents, Consolidated Funds, Fair Value		17,761	13,934
Level 2
Cash collateral pledged, Fair Value		13,342	10,085
Convertible debt, Fair Value	[2]	149,545	144,946
Notes payable and other debt, Fair Value	[3]	80,817	71,945
Level 3
Loans Receivable, Fair Value Disclosure	[4]	$ 31,088	$ 65,612

[1] The carrying amount of the convertible debt includes an unamortized discount of $17.8 million and $24.7 million as of December 31, 2016 and 2015.

[2] The convertible debt includes the conversion option and is based on the last broker quote available.

[3] Notes payable and other debt are based on the last broker quote available.

[4] The fair market value of level 3 loans is calculated using discounted cash flows.