Financial Instruments - Offsetting of Foreign Currency Derivative Contracts (Details) - Foreign currency exchange contract [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Gross Assets Recognized	$ 11,826	$ 3,780
Gross Amounts Offset in the Condensed Consolidated Balance Sheets	0	0
Net Amounts Presented in Condensed Consolidated Balance Sheets	11,826	3,780
Gross Amounts Not Offset in Condensed Consolidated Balance Sheets, Financial Instruments	1,307	3,780
Gross Amounts Not Offset in Condensed Consolidated Balance Sheets, Cash Collateral Pledged	0	0
Net Amount	10,519	0
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	1,307	10,625
Gross Amounts Offset in the Condensed Consolidated Balance Sheets	0	0
Net Amounts Presented in Condensed Consolidated Balance Sheets	1,307	10,625
Gross Amounts Not Offset in Condensed Consolidated Balance Sheets, Financial Instruments	1,307	3,780
Gross Amounts Not Offset in Condensed Consolidated Balance Sheets, Cash Collateral Received	0	0
Net Amount	$ 0	$ 6,845