Fair Value Measurements and Derivative Instruments (Derivative Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Total net derivative liability	$ (3,671)	$ (1,602)
Total derivative assets
Derivative [Line Items]
Derivative asset	1,716	1,386
Total derivative liabilities
Derivative [Line Items]
Derivative liability	(5,387)	(2,988)
Derivatives designated as hedging instruments | Foreign exchange contracts | Other current assets and prepayments
Derivative [Line Items]
Derivative asset	217	762
Derivatives designated as hedging instruments | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivative [Line Items]
Derivative liability	(208)	0
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other current assets and prepayments
Derivative [Line Items]
Derivative asset	1,499	624
Derivatives not designated as hedging instruments | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivative [Line Items]
Derivative liability	$ (5,179)	$ (2,988)