Fair Value Measurements and Derivative Instruments (Derivative Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Total net derivative asset (liabilities)	$ 1,402	$ (3,671)
Total derivative assets
Derivative [Line Items]
Total net derivative asset (liabilities)	3,508	1,716
Total derivative liabilities
Derivative [Line Items]
Total net derivative asset (liabilities)	(2,106)	(5,387)
Foreign exchange contracts | Derivatives designated as hedging instruments | Other current assets and prepayments
Derivative [Line Items]
Total net derivative asset (liabilities)	247	217
Foreign exchange contracts | Derivatives designated as hedging instruments | Accounts payable and accrued liabilities
Derivative [Line Items]
Total net derivative asset (liabilities)	(573)	(208)
Foreign exchange contracts | Derivatives not designated as hedging instruments | Other current assets and prepayments
Derivative [Line Items]
Total net derivative asset (liabilities)	3,261	1,499
Foreign exchange contracts | Derivatives not designated as hedging instruments | Accounts payable and accrued liabilities
Derivative [Line Items]
Total net derivative asset (liabilities)	(942)	(5,179)
Interest rate swaps | Derivatives designated as hedging instruments | Accounts payable and accrued liabilities
Derivative [Line Items]
Total net derivative asset (liabilities)	$ (591)	$ 0