Divestitures Joint Ventures Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended
	Jun. 30, 2013 JV Mississippi Lime	Sep. 30, 2013 JV Mississippi Lime	Jun. 30, 2013 JV Mississippi Lime Payment at Closing [Member]	Jun. 30, 2013 JV Mississippi Lime Payment Remaining [Member]	Sep. 30, 2013 JV Mississippi Lime Payment Remaining [Member]	Dec. 31, 2011 JV Utica	Sep. 30, 2013 JV Utica	Feb. 28, 2011 JV Niobrara	Sep. 30, 2013 JV Niobrara	Nov. 30, 2010 JV Eagle Ford	Sep. 30, 2013 JV Eagle Ford	Jan. 31, 2010 JV Barnett Shale	Sep. 30, 2013 JV Barnett Shale	Nov. 30, 2008 JVMarcellus	Sep. 30, 2013 JVMarcellus	Sep. 30, 2008 JV Fayetteville	Sep. 30, 2013 JV Fayetteville	Jul. 31, 2008 JV Haynesville And Bossier	Sep. 30, 2013 JV Haynesville And Bossier	Sep. 30, 2013 Corporate Joint Venture [Member]
Joint Ventures [Line Items]
Joint Venture Partner	Sinopec					TOT		CNOOC		CNOOC		TOT		STO		BP		FCX
Joint Venture Date	June 2013					December 2011		February 2011		November 2010		January 2010		November 2008		September 2008		July 2008
Interest Sold	50.00%					25.00%		33.30%		33.30%		25.00%		32.50%		25.00%		20.00%
Proceeds from Divestiture of Interest in Joint Venture	$ 1,020		$ 949	$ 71	$ 71	$ 610		$ 570		$ 1,120		$ 800		$ 1,250		$ 1,100		$ 1,650		$ 8,049
Total Drilling Carries	0					1,422		697		1,080		1,403		2,125		800		1,508		9,035
Total Cash And Drilling Carry Proceeds	949					2,032		1,267		2,200		2,203		3,375		1,900		3,158		17,084
Drilling Carries Remaining		$ 0					$ 714		$ 233		$ 0		$ 0		$ 0		$ 0		$ 0	$ 947
Percentage of Total Payment by Joint Venture Partner			93.00%		7.00%
Percentage Reimbursed							60.00%		67.00%