Unconsolidated VIE's (Details 9) - USD ($) $ in Thousands		Jun. 30, 2017	Mar. 31, 2017
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	[1]	$ 59,406	$ 58,723
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	[2]	78,408	89,473
Assets Under Management		27,013,127	26,735,285
Real Estate Investment Trusts [Member]
Variable Interest Entity
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	[1]	12,257	11,660
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	[2]	14,760	15,763
Other sponsored investments fund [Member]
Variable Interest Entity
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	[1]	47,149	47,063
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	[2]	$ 63,648	$ 73,710

[1] Amounts are related to investments in proprietary and other fund products.

[2] Includes equity investments the Company has made or is required to make and any earned but uncollected management fees.