Other Income (Expense), Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other Income and Expenses [Abstract]
Net gain (loss) on foreign currency exchange contracts	$ 1,865	$ (1,598)	$ 534	$ (1,364)
Net gain (loss) on foreign currency exchange transactions	(2,965)	1,006	(2,240)	1,336
Other income	18	(50)	37	(31)
Other income (expense), net	$ (1,082)	$ (642)	$ (1,669)	$ (59)