Derivatives (Fair Value Of Derivative Instruments And Locations In Balance Sheets) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Current derivative asset	$ 14,587	$ 31,139
Non-current derivative asset	137	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Current derivative asset	14,587	31,139
Non-current derivative asset	137	0
Total derivatives assets	$ 14,724	$ 31,139