Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments And Risk Management (Balance Sheet Classification And Fair Value Of Derivative Instruments) (Details)

v3.7.0.1
Financial Instruments And Risk Management (Balance Sheet Classification And Fair Value Of Derivative Instruments) (Details) - Currency Forward Contracts [Member] - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Mar. 31, 2016
Prepaid Expenses And Other Current Assets [Member] | Derivative Instruments Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative assets $ 6,347 $ 9,805 $ 409
Prepaid Expenses And Other Current Assets [Member] | Derivative Instruments Not Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative assets 292 1,361 7
Other Non-Current Assets [Member] | Derivative Instruments Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative assets 1,619 1,969 63
Accrued Liabilities [Member] | Derivative Instruments Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative liabilities 134 106 3,524
Accrued Liabilities [Member] | Derivative Instruments Not Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative liabilities 220 180 727
Other Long Term Liabilities [Member] | Derivative Instruments Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative liabilities $ 0 $ 0 $ 922