Derivatives (Fair Value Of Derivative Instruments And Locations In Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Current derivative assets	$ 10,186	$ 31,139
Non-current derivative assets	968	0
Total derivatives assets	11,154	31,139
Non-current derivative liabilities	285	0
Total derivative liabilities	285	0
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Current derivative assets	10,186	31,139
Non-current derivative assets	968	0
Current derivative liabilities	0	0
Non-current derivative liabilities	$ 285	$ 0