Financial Instruments - Gross Notional Amounts for Outstanding Derivatives (Details) - Forward contracts - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives Designated as Hedging Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	$ 154.3	$ 154.5
Derivatives Designated as Hedging Instruments | Prepaid and other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	0.9	1.3
Derivatives Designated as Hedging Instruments | Other accrued liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	4.3	0.5
Derivatives Not Designated as Hedging Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	309.8	227.2
Derivatives Not Designated as Hedging Instruments | Prepaid and other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	0.7	2.2
Derivatives Not Designated as Hedging Instruments | Other accrued liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	$ 5.4	$ 0.7