Summary of Significant Accounting Policies - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Additional paid-in capital	$ 2,984.3		$ 3,051.6
Long-term debt, net	1,070.5		1,025.3
Deferred taxes, net	144.0		163.6
Retained earnings	781.3		682.2
Interest expense	$ 1.6	$ 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