Changes in Level 3 Assets and Liabilities of CIVs (Details 5) (CIVs, Fair Value, Inputs, Level 3 [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
ASSETS:
Assets measured at fair value using significant unobservable inputs, value at beginning of period	$ 49,698	$ 46,430
Purchases	7,307	5,327
Sales	(8,885)	(8,037)
Redemptions/Settlements/Other	(34,042)	0
Transfers, Net	78	0
Realized and unrealized gains/(losses), net	(63)	5,978
Assets measured at fair value using significant unobservable inputs, value at end of period	14,093	49,698
Fair Value Disclosures [Abstract]
Total realized and unrealized gains (losses), net	(63)	1,587
Unrealized gains (losses) on Level 3 assets and liabilities still held at the reporting date	(79)	(2,284)
Hedge Funds
ASSETS:
Assets measured at fair value using significant unobservable inputs, value at beginning of period	17,888	19,448
Purchases	2,580	3,516
Sales	(5,761)	(8,037)
Redemptions/Settlements/Other	0	0
Transfers, Net	78	0
Realized and unrealized gains/(losses), net	(692)	2,961
Assets measured at fair value using significant unobservable inputs, value at end of period	14,093	17,888
Private Equity Funds
ASSETS:
Assets measured at fair value using significant unobservable inputs, value at beginning of period	31,810	26,982
Purchases	4,727	1,811
Sales	(3,124)	0
Redemptions/Settlements/Other	(34,042)	0
Transfers, Net	0	0
Realized and unrealized gains/(losses), net	629	3,017
Assets measured at fair value using significant unobservable inputs, value at end of period	0	31,810
Collateralized Debt Obligations [Member]
LIABILITIES:
Liabilities measured at fair value using significant unobservable inputs, value at beginning of period	(79,179)	(207,835)
Purchases	0	0
Sales	0	0
Redemptions/Settlements/Other	79,179	133,047
Transfers, Net	0	0
Realized and unrealized gains/(losses), net	0	(4,391)
Liabilities measured at fair value using significant unobservable inputs, value at end of period	$ 0	$ (79,179)