Derivatives and Hedging Activities Derivative Instruments and Hedging Activities - Cash Flow Hedge Activity Included in Accumulated Other Comprehensive Income (Loss) (Details) - Cash Flow Hedging [Member] - Cost of Sales [Member] - Foreign Exchange Forward [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	$ 2,063	$ 296
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	$ 743	$ 885