Investments - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Parenthetical) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Cash and cash equivalents	$ 112.3	$ 131.7
Restricted Cash	1.6	1.8
Funds Held for Clients	$ 1,667.7	$ 2,079.1