Consolidated Investment Products (CIP) - Investments Measured at NAV as a practical expedient (Details) - Investments in other private equity funds - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Fair Value	$ 211.8	$ 213.4
Total Unfunded Commitments	$ 72.3	$ 78.3
Weighted Average Remaining Term	6 years 9 months 18 days	6 years 8 months 12 days