Fair Value of Assets and Liabilities of CIVs by Level (Details 3) - Consolidated Investment Vehicles [Member] - USD ($) $ in Thousands		Jun. 30, 2017	Mar. 31, 2017
Proprietary Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 36,026	$ 28,300
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		67,241	33,991
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]	$ 23,054	$ 24,734

[1] Redemption restrictions: 4% daily redemption; 7% monthly redemption; 47% quarterly redemption; and 42% are subject to three to five-year lock-up or side pocket provisions.