Natural Gas Producing Activities (Unaudited) (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Natural Gas Producing Activities (Unaudited)
Discount rate percentage	10.00%
Future cash inflows	$ 25,912,542,000	$ 15,250,019,000	$ 22,145,953,000
Future production costs	(4,180,136,000)	(3,070,957,000)	(3,435,200,000)
Future development costs	(4,199,722,000)	(3,082,053,000)	(2,600,982,000)
Future income tax expenses	(6,533,817,000)	(3,324,472,000)	(6,075,539,000)
Future net cash flow	10,998,867,000	5,772,537,000	10,034,232,000
10% annual discount for estimated timing of cash flows	(7,047,588,000)	(3,617,378,000)	(6,101,408,000)
Standardized measure of discounted future net cash flows	3,951,279,000	2,155,159,000	3,932,824,000
Change in price of natural gas used in sensitivity analysis (in dollars per Dth)	1
Change in price of oil used in sensitivity analysis (in dollars per Bbl)	10
Change in discounted future cash flows for natural gas if assume $1 per Dth price change	3,200,000,000
Change in discounted future cash flows for oil if assume $10 per barrel price change	15,600,000
Schedule of changes in the standardized measure of discounted future net cash flows
Sales and transfers of natural gas and oil produced - net	(1,060,566,000)	(697,618,000)	(710,373,000)
Net changes in prices, production and development costs	(292,533,000)	(3,530,086,000)	52,057,000
Extensions, discoveries and improved recovery, less related costs	1,509,002,000	917,986,000	806,597,000
Development costs incurred	1,319,135,000	548,852,000	498,175,000
Purchase of minerals in place - net	348,608,000		46,178,000
Sale of minerals in place - net	(252,000)	(807,000)	(1,124,000)
Revisions of previous quantity estimates	106,170,000	(876,336,000)	(356,830,000)
Accretion of discount	343,502,000	622,072,000	478,165,000
Net change in income taxes	(1,031,105,000)	1,127,272,000	(560,360,000)
Timing and other	554,159,000	111,000,000	622,127,000
Net increase (decrease)	1,796,120,000	(1,777,665,000)	874,612,000
Beginning of year	2,155,159,000	3,932,824,000	3,058,212,000
End of year	$ 3,951,279,000	$ 2,155,159,000	$ 3,932,824,000