Consolidated Company-Sponsored Investment Funds - Offsetting of Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivative Asset [Abstract]
Cash Collateral Received	$ (300)	$ (4,800)
VIEs
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	4,833	3,410
Gross Amounts Offset in the Statement of Financial Condition	0	0
Net Amounts of Assets Presented in the Statement of Financial Condition	4,833	3,410
Financial Instruments	0	0
Cash Collateral Received	(1,631)	(856)
Net Amount	3,202	2,554
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	4,559	3,891
Gross Amounts Offset in the Statement of Financial Condition	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Condition	4,559	3,891
Financial Instruments	0	0
Cash Collateral Pledged	(3,155)	(829)
Net Amount	1,404	3,062
VOEs
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	4,339	3,816
Gross Amounts Offset in the Statement of Financial Condition	0	0
Net Amounts of Assets Presented in the Statement of Financial Condition	4,339	3,816
Financial Instruments	0	0
Cash Collateral Received	(534)	(225)
Net Amount	3,805	3,591
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	5,083	3,830
Gross Amounts Offset in the Statement of Financial Condition	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Condition	5,083	3,830
Financial Instruments	0	0
Cash Collateral Pledged	(1,201)	(547)
Net Amount	$ 3,882	$ 3,283