Income Taxes - Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of unrecognized tax benefits
Balance at beginning of year	$ 227.0	$ 203.0	$ 89.5
Additions based on tax positions related to the current year	14.0	13.8	14.9
Additions for tax positions of prior years	23.1	16.4	107.9
Reductions for tax positions of prior years	(22.1)	(3.3)	(3.6)
Settlements	(5.6)	(2.0)	0.0
Lapses of statutes of limitations	(7.9)	(0.9)	(5.7)
Balance at end of year	$ 228.5	$ 227.0	$ 203.0