Fair Values of Assets and Liabilities NAV Investments (Details 4) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2016		Mar. 31, 2016
Funds-Of-Hedge Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
PercentageDailyRedemption	1.00%
Percentage of Monthly Redemption	11.00%
Percentage of Quarterly Redemption	14.00%
Percentage Not Subject to Redemption	74.00%
Other Investments [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of Redemption, Investment Funds	28.00%
Percentage of Investment of 20 Year Redemption	72.00%
Consolidated Entity Excluding Consolidated Investment Vehicles Before Eliminations [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Alternative Investments, Fair Value Disclosure	$ 47,664		$ 51,691
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	27,436
Consolidated Entity Excluding Consolidated Investment Vehicles Before Eliminations [Member] | Funds-Of-Hedge Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Alternative Investments, Fair Value Disclosure	18,707	[1]	19,139
Consolidated Entity Excluding Consolidated Investment Vehicles Before Eliminations [Member] | Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Alternative Investments, Fair Value Disclosure	10,300		11,403
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	20,000
Consolidated Entity Excluding Consolidated Investment Vehicles Before Eliminations [Member] | Private Equity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Alternative Investments, Fair Value Disclosure	18,433	[2]	20,471
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 7,436
Investments Remaining Term, High End of Range	12 years
Consolidated Entity Excluding Consolidated Investment Vehicles Before Eliminations [Member] | Other Investments [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Alternative Investments, Fair Value Disclosure	$ 224	[3]	$ 678
Investments Remaining Term, Category One	1 year
Investments Remaining Term, Category Two	15 years

[1] Liquidation restrictions: 1% daily redemption, 11% monthly redemption, 14% quarterly redemption, and 74% are not subject to redemption or are not currently redeemable.

[2] Liquidations are expected over the remaining term.

[3] Of this balance, 28% has a remaining term of less than one year and 72% has a remaining term of 15 years.