Derivative Financial Instruments and Hedging Activities - Statement of Financial Position (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Asset	$ 21,032	$ 19,320
Derivative Liability	(2,433)	(7,240)
Other current assets
Derivatives, Fair Value [Line Items]
Derivative Asset	2,884	1,756
Other assets
Derivatives, Fair Value [Line Items]
Derivative Asset	18,148	17,564
Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	(345)	(835)
Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	(2,088)	(6,405)
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency exchange contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Asset	2,286	692
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Derivative Asset	538	33
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency exchange contracts | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	(37)	(261)
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency option contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Asset	389	1,064
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency option contracts | Other assets
Derivatives, Fair Value [Line Items]
Derivative Asset	137	327
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency option contracts | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	(119)	(574)
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency option contracts | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	(55)	(426)
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Other assets
Derivatives, Fair Value [Line Items]
Derivative Asset	17,473	17,204
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	(2,033)	(5,979)
Not Designated as Hedging Instrument | Foreign currency exchange contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Asset	209	0
Not Designated as Hedging Instrument | Foreign currency exchange contracts | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability	$ (189)	$ 0