Consolidated Company-Sponsored Investment Funds (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Derivative [Line Items]
Gain (loss) on derivative instruments	$ (9,492,000)	$ (3,557,000)
Cash collateral payable to trade counterparties	0		$ 800,000
Cash collateral received	8,100,000		6,200,000
Net assets of investment products that are non-consolidated VIEs	49,300,000,000
Maximum risk of loss in investment in VIEs	23,600,000
VIEs
Derivative [Line Items]
Futures, forwards and swaps held	20,400,000		2,900,000
Asset Derivatives	20,900,000		3,200,000
Gain (loss) on derivative instruments	7,200,000	$ 3,000,000
Cash collateral payable to trade counterparties	652,000		461,000
Cash collateral received	5,600,000		$ 3,300,000
VOEs
Derivative [Line Items]
Futures, forwards and swaps held	43,105
Gain (loss) on derivative instruments	(400,000)
Cash collateral payable to trade counterparties	0
Cash collateral received	$ 300,000