Variable Interest Entities - Consolidated VIEs (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Carrying amounts of consolidated VIE assets and liabilities
Total assets	$ 291,538.5	$ 304,657.2
Total liabilities	279,279.0	288,198.9
Redeemable noncontrolling interest	306.8	332.5	$ 263.5	$ 255.6
Aggregate consolidated variable interest entities
Carrying amounts of consolidated VIE assets and liabilities
Total assets	38,239.0	37,269.2
Total liabilities	35,144.1	34,360.7
Redeemable noncontrolling interest	278.3	304.0
Mandatory retirement savings funds
Carrying amounts of consolidated VIE assets and liabilities
Total assets	35,441.7	34,687.0
Total liabilities	35,064.9	34,301.8
Real estate VIE
Carrying amounts of consolidated VIE assets and liabilities
Total assets	664.8	709.6
Total liabilities	32.7	36.1
Sponsored investment funds
Carrying amounts of consolidated VIE assets and liabilities
Total assets	553.8	609.4
Total liabilities	7.5	2.5
Redeemable noncontrolling interest	278.3	304.0
Residential mortgage loans VIE
Carrying amounts of consolidated VIE assets and liabilities
Total assets	1,578.7	1,263.2
Total liabilities	$ 39.0	$ 20.3