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
Jun. 30, 2017
Dec. 31, 2016
Jun. 30, 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 $ 1,648 $ 9,805 $ 2,228
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 505 1,361 458
Other Non-Current Assets [Member] | Derivative Instruments Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative assets 816 1,969 1,079
Accrued Liabilities [Member] | Derivative Instruments Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative liabilities 3,151 106 4,169
Accrued Liabilities [Member] | Derivative Instruments Not Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative liabilities 916 180 3,545
Other Long Term Liabilities [Member] | Derivative Instruments Designated As Cash Flow Hedges [Member]      
Derivatives, Fair Value [Line Items]      
Fair value of derivative liabilities $ 1,665 $ 0 $ 1,456