Financial Instruments - Fair Values of Derivative Instruments in Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 3.5	$ 25.5
Liability Derivatives	0.6	1.9
Derivatives designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives	1.0	0.0
Liability Derivatives	0.2	1.0
Derivatives designated as hedging instruments | Other Current Assets | Interest rate contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	1.0	0.0
Derivatives designated as hedging instruments | Other Accrued & Current Liabilities | Interest rate contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	0.2	1.0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives	2.5	25.5
Liability Derivatives	0.4	0.9
Derivatives not designated as hedging instruments | Other Current Assets | Foreign exchange collar
Derivatives, Fair Value [Line Items]
Asset Derivatives	0.0	23.5
Derivatives not designated as hedging instruments | Other Current Assets | Foreign exchange forward contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	2.5	2.0
Derivatives not designated as hedging instruments | Other Accrued & Current Liabilities | Foreign exchange collar
Derivatives, Fair Value [Line Items]
Liability Derivatives	0.0	0.0
Derivatives not designated as hedging instruments | Other Accrued & Current Liabilities | Foreign exchange forward contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 0.4	$ 0.9