Fair Value Measurements, Equity Investments and Other Financial Instruments - Fair Value Measurements of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 290.0	$ 235.1
Foreign currency forward and option contracts
Derivative financial and hedging instruments net asset:
Derivative financial and hedging instruments net asset	2.1	0.3
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	290.0	235.1
Level 1 | Foreign currency forward and option contracts
Derivative financial and hedging instruments net asset:
Derivative financial and hedging instruments net asset	0.0	0.0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0.0	0.0
Level 2 | Foreign currency forward and option contracts
Derivative financial and hedging instruments net asset:
Derivative financial and hedging instruments net asset	2.1	0.3
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0.0	0.0
Level 3 | Foreign currency forward and option contracts
Derivative financial and hedging instruments net asset:
Derivative financial and hedging instruments net asset	$ 0.0	$ 0.0