Redeemable Non-Controlling Interests (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Redeemable Noncontrolling Interest [Roll Forward]
Balance, beginning balance	$ 393.4
Decrease attributable to consolidated Affiliate sponsored investment products	(8.2)
Transfers to Other liabilities	(10.3)
Changes in redemption value	18.1	$ 101.7
Balance, ending balance	$ 393.0
Minimum
Noncontrolling Interest [Line Items]
Term of conditional right to put interest	5 years
Maximum
Noncontrolling Interest [Line Items]
Term of conditional right to put interest	15 years
Variable Interest Entity, Primary Beneficiary
Redeemable Noncontrolling Interest [Roll Forward]
Balance, beginning balance	$ 11.8
Balance, ending balance	$ 3.6