Fair Value Measurements and Risk - Narrative (Details) € in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 EUR (€) Currency country	Jun. 30, 2018 USD ($) Currency country	Apr. 03, 2018 EUR (€)	Apr. 03, 2018 USD ($)	Feb. 03, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of countries in which entity operates | country					60	60
Number of currencies used | Currency					30	30
Maturities in which forward contracts are designated as cash flow hedges or forecasted repayments of intercompany loans			36 months
Deferred intercompany royalties designated as hedging instrument | €					€ 22.5
Currency contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total contract value						$ 67,100,000
Variable-to-fixed cross-currency derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of debt hedged								$ 600,000,000
Fixed interest rate							2.0231%	2.0231%
Variable-to-fixed cross-currency derivatives | 2025 Term Loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total contract value | €							€ 490.1
Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of debt hedged								$ 100,000,000	$ 250,000,000
Fixed interest rate							2.775%	2.775%	2.393%
Cross-currency swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total contract value | €					€ 170.0
Net Investment Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of Gain (Loss) Reclassified from OCI into Income	$ 0	$ 0	$ 0	$ 0