Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Provision for Income Taxes
Income tax expense (benefit)	$ 21.3	$ 7.1	$ 48.8	$ 10.0
Effective tax rates (as a percent)	26.60%	22.70%	29.50%	22.30%
Unrecognized tax benefits, excluding penalties and interest	$ 26.2		$ 26.2		$ 22.7
Accrued interest and penalties related to uncertain tax positions	2.1		2.1		$ 1.8
Penalties and interest (benefit) expense relating to unrecognized tax benefits	$ 0.2	$ 0.1	$ 0.3	$ 0.3
Statutory tax rate (as a percent)			21.00%
Change in tax rate - foreign jurisdictions (as a percent)			5.00%
Germany
Provision for Income Taxes
Statutory tax rate (as a percent)			30.00%
Switzerland
Provision for Income Taxes
Statutory tax rate (as a percent)			20.00%