Derivatives (Fair Value Of Derivative Instruments And Locations In Balance Sheets) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Current derivative asset	$ 13,901	$ 10,186
Non-current derivative asset	942	968
Total derivatives assets	14,843	11,154
Non-current derivative liability	185	285
Total derivative liabilities	$ 185	$ 285