Asset Impairments Impaired Long-Lived Assets Held and Used- text (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments	$ 5	$ 92	$ 533	$ 500
Other (Onshore US)
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments			481
Gulf of Mexico and Eastern Mediterranean
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments			$ 47
United States
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments				250
South Raton (Deepwater Gulf of Mexico)
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments				74
Other Deepwater Gulf of Mexico
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments				51
Reclassification Of Non-Strategic Properties As Held For Sale
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments				$ 31