Summary of Significant Accounting Policies (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Additional paid-in capital	$ 2,995.7		$ 2,995.7		$ 3,051.6
Long-term debt, net	1,067.4		1,067.4		1,025.3
Deferred taxes, net	(119.3)		(119.3)		(163.6)
Retained earnings	886.7		886.7		682.2
Interest expense	$ 1.6	$ 0.0	$ 3.2	$ 0.0
Cumulative Effect, Period of Adoption, Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Additional paid-in capital					57.1
Long-term debt, net					57.9
Deferred taxes, net					13.2
Retained earnings					$ 12.4
Common stock, shares, outstanding (in shares)					14.7