Accrued Compensation and Benefits - Performance Allocations and Incentive Fee Related Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Realized	$ 473.8	$ 1,026.4	$ 1,414.5
Unrealized	629.9	(306.5)	1,546.5
Total	1,103.7	$ 719.9	$ 2,961.0
One time charge to incremental expense	$ 1,100.0