Fair Value of Financial Instruments (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets:
Short-term investments	$ 94,202	$ 82,847
Foreign currency forward exchange contracts not accounted for using hedge accounting		123
Total assets		82,970
Liabilities:
Foreign currency forward exchange contracts accounted for using hedge accounting	181
Foreign currency forward exchange contracts not accounted for using hedge accounting	418
Interest rate swap	908	1,026
Total Liabilities	1,507
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Short-term investments	0	0
Foreign currency forward exchange contracts not accounted for using hedge accounting		0
Total assets		0
Liabilities:
Foreign currency forward exchange contracts accounted for using hedge accounting	0
Foreign currency forward exchange contracts not accounted for using hedge accounting	0
Interest rate swap	0	0
Total Liabilities	0
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Short-term investments	94,202	82,847
Foreign currency forward exchange contracts not accounted for using hedge accounting		123
Total assets		82,970
Liabilities:
Foreign currency forward exchange contracts accounted for using hedge accounting	181
Foreign currency forward exchange contracts not accounted for using hedge accounting	418
Interest rate swap	908	1,026
Total Liabilities	1,507
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Short-term investments	0	0
Foreign currency forward exchange contracts not accounted for using hedge accounting		0
Total assets		0
Liabilities:
Foreign currency forward exchange contracts accounted for using hedge accounting	0
Foreign currency forward exchange contracts not accounted for using hedge accounting	0
Interest rate swap	0	$ 0
Total Liabilities	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Fair value as of the balance sheet date of all foreign currency derivative assets not designated as hedging instruments.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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