Financial Instruments - Offsetting of Foreign Currency Derivative Contracts (Details) - Foreign currency exchange contract [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Foreign exchange contracts liabilities [Line Items]
Gross Amounts Offset in the Consolidated Balance Sheets, Gross Amount Recognized	$ 549	$ 2,138
Gross Amounts Offset in the Consolidated Balance Sheets, Gross Amount Offset	0	0
Gross Amounts Offset in the Consolidated Balance Sheets, Net Amount Presented	549	2,138
Gross Amounts Not Offset in the Consolidated Balance Sheets, Financial Instruments	549	0
Gross Amounts Not Offset in the Consolidated Balance Sheets, Cash Collateral Received	0	0
Gross Amounts Not Offset in the Consolidated Balance Sheets, Net Amount	0	2,138
Foreign exchange contracts assets [Line Items]
Gross Amounts Offset in the Consolidated Balance Sheets, Gross Amount Recognized	623	0
Gross Amounts Offset in the Consolidated Balance Sheets, Gross Amount Offset	0	0
Gross Amounts Offset in the Consolidated Balance Sheets, Net Amount Presented	623	0
Gross Amounts Not Offset in the Consolidated Balance Sheets, Financial Instruments	549	0
Gross Amounts Not Offset in the Consolidated Balance Sheets, Cash Collateral Received	0	0
Gross Amounts Not Offset in the Consolidated Balance Sheets, Net Amount	$ 74	$ 0

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