Fair-Value Measurements (Schedule of (Losses)/Gains on Changes in Fair Value of Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Derivatives not designated as hedging instruments Foreign currency options gains/(losses)	$ 10	$ (2)	$ (61)	$ (131)