Income Taxes - Significant Components of Income Before Income Taxes as Used for Income Tax Purposes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Components of income before income taxes as used for income tax purposes
Domestic	$ 2,106.8	$ 2,317.9	$ 1,899.6
Foreign	141.8	201.3	82.2
Income before income taxes	$ 2,248.6	$ 2,519.2	$ 1,981.8