Financial Instruments - Gross Notional Amounts for Outstanding Derivatives (Details) - Forward contracts - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
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	$ 154.5	$ 183.0
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	1.3	3.1
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	0.5	0.9
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	227.2	182.7
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	2.2	4.1
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	$ 0.7	$ 1.1