Derivative Financial Instruments (Fair Value of Derivative Assets and Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Foreign Currency Derivatives [Abstract]
Derivative asset	$ 4,350	$ 6,541
Derivative liability	(1,597)	(6,698)
Foreign currency forward contract derivatives	2,753	(157)
Level 1 [Member]
Foreign Currency Derivatives [Abstract]
Derivative asset	0	0
Derivative liability	0	0
Level 2 [Member]
Foreign Currency Derivatives [Abstract]
Derivative asset	4,350	6,541
Derivative liability	(1,597)	(6,698)
Level 3 [Member]
Foreign Currency Derivatives [Abstract]
Derivative asset	0	0
Derivative liability	$ 0	$ 0