Disclosure About Oil and Gas Producing Activities (Unaudited) (Details)	12 Months Ended
	Dec. 31, 2013 bbl	Dec. 31, 2012 bbl	Dec. 31, 2011 bbl
Oil Reserves [Member]
Increase (Decrease) in Proved Developed and Undeveloped Reserves [Roll Forward]
Reserves, Beginning Balance	18,137,000	33,081,000	31,684,000
Extensions, discoveries and additions	11,329,000	5,435,000	7,425,000
Acquisitions	10,114,000
Production	(1,196,000)	(1,282,000)	(1,408,000)
Revisions	(4,265,000)	(19,097,000)	(4,620,000)
Reserves, Ending Balance	34,119,000	18,137,000	33,081,000
Natural Gas Reserves [Member]
Increase (Decrease) in Proved Developed and Undeveloped Reserves [Roll Forward]
Reserves, Beginning Balance	2,966,445,000	4,778,554,000	4,200,155,000
Extensions, discoveries and additions	1,409,528,000	819,896,000	1,452,122,000
Acquisitions	0
Production	(224,912,000)	(249,310,000)	(236,832,000)
Revisions	(741,319,000)	(2,382,695,000)	(636,891,000)
Reserves, Ending Balance	3,409,742,000	2,966,445,000	4,778,554,000