Derivatives and Hedging - Location of Gains in Consolidated Condensed Statements of Operations that were Recognized and Derivative Contract Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Forward points expensed on derivatives	$ 61
Other (expense) income, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Net Gain (Loss) Recognized in Income on Derivative Instruments	(3,860)	$ (5,175)
Foreign Exchange Forward | Cost Of Goods Sold
Derivative Instruments, Gain (Loss) [Line Items]
Gain Reclassified from AOCI into COGS	$ 45	$ 902