Variable Interest Entities - Consolidated VIEs (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Carrying amounts of consolidated VIE assets and liabilities
Total assets	$ 299,408.2	$ 290,578.3
Total liabilities	288,874.7	280,298.5
Redeemable noncontrolling interest	272.7	262.0	$ 306.8	$ 332.5
Aggregate consolidated variable interest entities
Carrying amounts of consolidated VIE assets and liabilities
Total assets	39,409.7	37,220.5
Total liabilities	36,706.9	34,614.9
Redeemable noncontrolling interest	250.9	235.3
Mandatory retirement savings funds
Carrying amounts of consolidated VIE assets and liabilities
Total assets	36,985.1	34,876.9
Total liabilities	36,606.1	34,528.3
Real estate VIE
Carrying amounts of consolidated VIE assets and liabilities
Total assets	753.6	689.6
Total liabilities	52.2	42.2
Sponsored investment funds
Carrying amounts of consolidated VIE assets and liabilities
Total assets	501.4	471.4
Total liabilities	7.2	2.6
Redeemable noncontrolling interest	250.9	235.3
Residential mortgage loans VIE
Carrying amounts of consolidated VIE assets and liabilities
Total assets	1,169.6	1,182.6
Total liabilities	$ 41.4	$ 41.8