Derivatives and Hedging Activities - Fair Value of Derivative Instruments (Details) € in Millions, $ in Millions	Mar. 31, 2019 EUR (€)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Derivatives not designated as hedging instruments:
Total Derivative Assets		$ 3.3	$ 3.5
Total Derivative Liabilities		(3.2)	(2.9)
Net Derivatives		0.1	0.6
Long-term debt, less current portion		3,284.6	3,236.5
Foreign currency forward contracts
Derivatives not designated as hedging instruments:
Total Derivative Assets		3.3	3.5
Total Derivative Liabilities		(3.2)	(2.9)
Designated as Hedging Instruments | Foreign currency forward contracts
Derivatives not designated as hedging instruments:
Long-term debt, less current portion	€ 400.0	446.1	454.9
Designated as Hedging Instruments | Cash Flow Hedge
Derivatives not designated as hedging instruments:
Total Derivative Assets		0.9	1.8
Total Derivative Liabilities		(0.6)	(0.2)
Net Derivatives		0.3	1.6
Designated as Hedging Instruments | Cash Flow Hedge | Foreign currency forward contracts
Derivatives not designated as hedging instruments:
Total Derivative Assets		0.9	1.8
Total Derivative Liabilities		(0.6)	(0.2)
Non-Designated as Hedging Instruments
Derivatives not designated as hedging instruments:
Total Derivative Assets		2.4	1.7
Total Derivative Liabilities		(2.6)	(2.7)
Net Derivatives		(0.2)	(1.0)
Non-Designated as Hedging Instruments | Foreign currency forward contracts
Derivatives not designated as hedging instruments:
Total Derivative Assets		2.4	1.7
Total Derivative Liabilities		$ (2.6)	$ (2.7)