Derivative Financial Instruments Derivative Instruments and Hedging Activities - Cash Flow Hedge Activity Included in Accumulated Other Comprehensive Income (Loss) (Details) - Cost of Sales [Member] - Foreign Exchange Forward [Member] - Cash Flow Hedging [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion	$ (264)	$ 1,743	$ 1,421	$ 2,256
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	$ 229	$ 192	$ 573	$ 687