Derivative Instruments And Hedging Activities - Derivative Instruments Designated As Hedging Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Asset derivative instruments designated as hedging instruments	$ 717	$ 1,064
Liability derivative instruments designated as hedging instruments	4,167	6,211
Other Current Assets | Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Asset derivative instruments designated as hedging instruments	685	863
Other Assets, Net | Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Asset derivative instruments designated as hedging instruments	32	201
Accrued Liabilities | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Liability derivative instruments designated as hedging instruments	4,167	5,857
Other Non-Current Liabilities | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Liability derivative instruments designated as hedging instruments	$ 0	$ 354