Asset Impairments (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
Onshore US
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments		0	0	42
Deepwater Gulf of Mexico
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments		0	158	350
Equatorial Guinea
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments		0	339	0
Eastern Mediterranean
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments		88	36	14
North Sea
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments		0	0	94
Other International and Corporate
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments		4	$ 0	$ 0
Leviathan-1 Deep
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairments		$ 88