Dispositions (Details) (USD $)	9 Months Ended		1 Months Ended		1 Months Ended			3 Months Ended	1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013 DJ Basin [Member]	Feb. 28, 2013 Marcellus Shale [Member]	Feb. 28, 2013 Neptune Gas Plant [Member]	Jan. 31, 2013 Alaska EP [Member]	Jun. 30, 2013 Angola Blk 31 [Member]	Sep. 30, 2012 Eagle Ford Shale Member [Member] acre	Jan. 31, 2012 GOM Pipelines [Member]	May 31, 2012 Indonesia [Member]
Dispositions Detail [Line Items]
Gas and oil acreages undeveloped and developed net								5,800
Pretax gain/loss on sale			$ (114,000,000)	$ (43,000,000)	$ 98,000,000	$ 55,000,000		$ (18,000,000)	$ 166,000,000	$ (36,000,000)
Interest Percentage							10.00%
Proceeds from Sale of Oil and Gas Property and Equipment	402,000,000	193,000,000	19,000,000		166,000,000	195,000,000		9,000,000	206,000,000	(36,000,000)
Proceeds from Sale of Oil and Gas Property and Equipment, Six Month Escrow						50,000,000
Transaction Value, Disposition							$ 1,500,000,000