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, 2013		Dec. 31, 2012		Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income	$ 603		$ 51,853		$ 2,965
Amount of Gain or (Loss) Recognized in Income	(190)		(2,616)
Commodity Derivatives [Member] | Oil and natural gas revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income	603	[1]	51,853	[1]	2,965	[1]
Commodity Derivatives [Member] | Gain (loss) on derivatives not designated as hedges and hedge ineffectiveness [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain on Derivative	$ (190)	[2]	$ (2,616)	[2]	$ 2,749	[2]

[1] Effective portion of gain (loss).

[2] Ineffective portion of gain (loss).