Supplemental Oil And Gas Disclosures (Schedule Of Base Prices Used In Determining The Standardized Measure) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplemental Oil and Gas Disclosures [Abstract]
Base prices, Barrel	$ 104.85	$ 105.35	$ 77.55
Base prices, Mcf	$ 3.38	$ 4.34	$ 4.40