Derivatives Balance Sheet Location (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative assets	$ 1,972	$ 1,020
Other Current Assets | Foreign currency forward contracts | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1,891	792
Other Current Assets | Foreign currency forward contracts | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	81	228
Accrued Expenses
Derivatives, Fair Value [Line Items]
Derivative liabilities	428	219
Accrued Expenses | Foreign currency forward contracts | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	133	210
Accrued Expenses | Foreign currency forward contracts | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 295	$ 9