Fair Value Measurement (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets:
Short-term investments	$ 71,867	$ 67,870
Foreign currency forward exchange contracts accounted for using hedge accounting		179
Total Assets		68,049
Liabilities:
Interest rate swap	149	207
Foreign currency forward exchange contracts accounted for using hedge accounting	349
Foreign currency forward exchange contracts not accounted for using hedge accounting	19	45
Total Liabilities	517	252
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Short-term investments
Foreign currency forward exchange contracts accounted for using hedge accounting
Total Assets
Liabilities:
Interest rate swap
Foreign currency forward exchange contracts accounted for using hedge accounting
Foreign currency forward exchange contracts not accounted for using hedge accounting
Total Liabilities
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Short-term investments	71,867	67,870
Foreign currency forward exchange contracts accounted for using hedge accounting		179
Total Assets		68,049
Liabilities:
Interest rate swap	149	207
Foreign currency forward exchange contracts accounted for using hedge accounting	349
Foreign currency forward exchange contracts not accounted for using hedge accounting	19	45
Total Liabilities	517	252
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Short-term investments
Foreign currency forward exchange contracts accounted for using hedge accounting
Total Assets
Liabilities:
Interest rate swap
Foreign currency forward exchange contracts accounted for using hedge accounting
Foreign currency forward exchange contracts not accounted for using hedge accounting
Total Liabilities

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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-SubTopic 10
-Section 50
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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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-Name Accounting Standards Codification
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Fair value as of the balance sheet date of all foreign currency derivative liabilities not designated as hedging instruments.

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Fair value as of the balance sheet date of all derivative assets designated as foreign currency fair value hedging instruments.

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Fair value as of the balance sheet date of all derivative liabilities designated as foreign currency fair value 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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-Publisher FASB
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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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