Derivatives (Gain Or Loss Of Reclassified Accumulated Other Comprehensive Income And Recognized Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ 0		$ 0
Commodity Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income	0		603
Amount of Gain or (Loss) Recognized in Income	0		(190)
Commodity Contract | Oil and natural gas revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income	0	[1]	603	[1]	51,853
Commodity Contract | Gain (loss) on derivatives not designated as hedges and hedge ineffectiveness
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Income	$ 0	[2]	$ (190)	[2]	$ (2,616)

[1] Effective portion of gain (loss).

[2] Ineffective portion of gain (loss).