Dispositions - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from asset sales	$ 22	$ 607	$ 3,296
Gain (loss) on asset sales, pre-tax	22	32	(86)
Loss included recognition earnings for cumulative translation adjustments	0	0	900
Miscellaneous Non-core Assets
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from asset sales			194
Gain (loss) on asset sales, pre-tax			12
Gain (loss) on asset sale, after income taxes			12
Ghana
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Agreement entered to sell interest, total consideration		100
Proceeds from asset sales		25
Gain (loss) on asset sales, pre-tax		10
Gain (loss) on asset sale, after income taxes		10
Equatorial Guinea
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from asset sales			449
Gain (loss) on asset sales, pre-tax			486
Gain (loss) on asset sale, after income taxes			486
Payable upon approval of the Plan of Development | Ghana
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Agreement entered to sell interest, total consideration		75
Utica Shale Play, Eastern Ohio | Eastern Ohio
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from asset sales	22	396
Gain (loss) on asset sales, pre-tax	22	14
Gain (loss) on asset sale, after income taxes	$ 22	$ 14
Permian Basin
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from asset sales			597
Gain (loss) on asset sales, pre-tax			273
Gain (loss) on asset sale, after-tax and non-controlling interests			280
Permian Basin | Exploration and Production
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on asset sale, after-tax and non-controlling interests			314
Permian Basin | Midstream
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on asset sale, after-tax and non-controlling interests			(34)
Offshore Norway
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from asset sales			2,056
Gain (loss) on asset sales, pre-tax			(857)
Gain (loss) on asset sale, after income taxes			(857)
Loss included recognition earnings for cumulative translation adjustments			$ 900