Fair Value Measurements and Derivative Instruments (Derivative Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Total net derivative asset (liabilities)	$ 2,682	$ (1,492)
Total derivative assets
Derivative [Line Items]
Total net derivative asset (liabilities)	2,945	2,225
Total derivative liabilities
Derivative [Line Items]
Total net derivative asset (liabilities)	(263)	(3,717)
Foreign exchange contracts | Derivatives designated as hedging instruments | Other current assets and prepayments
Derivative [Line Items]
Total net derivative asset (liabilities)	353	487
Foreign exchange contracts | Derivatives designated as hedging instruments | Accounts payable and accrued liabilities
Derivative [Line Items]
Total net derivative asset (liabilities)	(35)	(136)
Foreign exchange contracts | Derivatives not designated as hedging instruments | Other current assets and prepayments
Derivative [Line Items]
Total net derivative asset (liabilities)	536	150
Foreign exchange contracts | Derivatives not designated as hedging instruments | Accounts payable and accrued liabilities
Derivative [Line Items]
Total net derivative asset (liabilities)	(228)	(3,581)
Interest rate swap | Derivatives designated as hedging instruments | Other current assets and prepayments
Derivative [Line Items]
Total net derivative asset (liabilities)	$ 2,056	$ 1,588