Income Taxes - Income Tax Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 116.0	$ 113.4	$ 116.0
Tax positions related to current year:
Additions	8.9	5.8	7.7
Tax positions related to prior years:
Additions	8.9	6.9	3.3
Reductions	0.0	(2.5)	(3.6)
Settlements	0.0	0.0	(9.4)
Lapses in statutes of limitations	(1.0)	(7.6)	(0.6)
Balance at end of year	$ 132.8	$ 116.0	$ 113.4