Consolidated Company-Sponsored Investment Funds (Offsetting of Derivative Assets and Liabilities) (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Derivative Asset [Abstract]
Cash Collateral Received	$ 0	$ (800,000)
VIEs
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	25,255,000	4,997,000
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	25,255,000	4,997,000
Financial Instruments	0	0
Cash Collateral Received	(652,000)	(461,000)
Net Amount	24,603,000	4,536,000
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	4,868,000	2,081,000
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	4,868,000	2,081,000
Financial Instruments	0	0
Collateral Pledged	(4,868,000)	(2,081,000)
Net Amount	0	$ 0
VOEs
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	43,000
Gross Amounts Offset in the Statement of Financial Position	0
Net Amounts of Assets Presented in the Statement of Financial Position	43,000
Financial Instruments	0
Cash Collateral Received	0
Net Amount	43,000
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	0
Gross Amounts Offset in the Statement of Financial Position	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	0
Financial Instruments	0
Collateral Pledged	0
Net Amount	$ 0