Supplementary Oil and Natural Gas Disclosures (Unaudited) (Oil and Natural Gas Computed Price Used in Computation of Discounted Future Net Cash Flows) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Supplementary Oil and Natural Gas Disclosures (Unaudited) [Abstract]
Computed Price Per Barrel of Oil	105.13	108.48
Computed prices Per mcf for Natural Gas	2.92	4.16