Summary of Significant Accounting Policies (Details 4)	12 Months Ended
Dec. 31, 2017
Foreign Exchange Forward \| Maximum
Derivative [Line Items]
Maximum typical term of foreign currency forward exchange contracts (in days)	90 days

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Period Type:	duration