Fair Value - Fair Value of Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, at carrying value	$ 206.7	$ 271.3
Reported Value Measurement [Member] | Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.2	1.9
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, at fair value	206.7	271.3
Estimate of Fair Value Measurement [Member] | Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.2	1.9
Foreign Exchange Forward [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	5.8	5.0
Foreign Exchange Forward [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	3.3	3.4
Foreign Exchange Forward [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0.1	0.0
Foreign Exchange Forward [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0.1	0.0
Foreign Exchange Forward [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	5.8	5.0
Foreign Exchange Forward [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	3.3	3.4
Foreign Exchange Forward [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0.1	0.0
Foreign Exchange Forward [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0.1	0.0
Currency Swap [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.0	1.1
Currency Swap [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	20.6	0.0
Currency Swap [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.0	1.1
Currency Swap [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	20.6	0.0
Interest Rate Swap [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Assets, at Fair Value	4.9	0.9
Interest Rate Swap [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Assets, at Fair Value	8.6	2.2
Interest Rate Swap [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	17.8	7.9
Interest Rate Swap [Member] | Reported Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	32.1	18.4
Interest Rate Swap [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Assets, at Fair Value	4.9	0.9
Interest Rate Swap [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Assets, at Fair Value	8.6	2.2
Interest Rate Swap [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	17.8	7.9
Interest Rate Swap [Member] | Estimate of Fair Value Measurement [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	$ 32.1	$ 18.4