Fair Values of Assets and Liabilities NAV Investments (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017		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	12.00%
Percentage Not Subject to Redemption	76.00%
Other Investments [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of Redemption, Investment Funds	26.00%
Percentage of Investment of 20 Year Redemption	74.00%
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	$ 52,772		$ 58,158
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	27,236
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	18,537	[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	10,107		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	17,612	[2]	20,471
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 7,236
Investments Remaining Term, High End of Range	12 years
Consolidated Entity Excluding Consolidated Investment Vehicles Before Eliminations [Member] | Real Estate Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Alternative Investments, Fair Value Disclosure	$ 6,292		6,467
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, 12% quarterly redemption, and 76% are not subject to redemption or are not currently redeemable.

[2] Liquidations are expected over the remaining term.

[3] Of this balance, 26% has a remaining term of less than one year and 74% has a remaining term of 15 years.