Fair Value Measurements (Details) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended
	May 31, 2020 USD ($)	Jun. 30, 2020 USD ($) $ / Barrel $ / MillionCubicFeet	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Embedded derivatives
Impairment and related charges		$ 8,600
Goodwill impairment			$ 1,200
Low end of range
Embedded derivatives
Operating and capital cost estimates, percentage		1.00%
Operating and capital cost estimates (in dollars per barrel) | $ / Barrel		50
High end of range
Embedded derivatives
Operating and capital cost estimates, percentage		2.00%
Operating and capital cost estimates (in dollars per barrel) | $ / Barrel		60
Crude Oil
Embedded derivatives
Sales price (dollars per barrel) | $ / Barrel		62.42
Unweighted arithmetic average price (in dollars per barrel) | $ / Barrel		59.17
Unweighted arithmetic average price, period		15 years
Crude Oil | Low end of range
Embedded derivatives
Sales price (dollars per barrel) | $ / Barrel		40
Crude Oil | High end of range
Embedded derivatives
Sales price (dollars per barrel) | $ / Barrel		70
Natural Gas
Embedded derivatives
Unweighted arithmetic average price (in dollars per barrel) | $ / MillionCubicFeet		3.13
Unweighted arithmetic average price, period		15 years
Natural Gas | Low end of range
Embedded derivatives
Sales price (dollars per barrel) | $ / MillionCubicFeet		2.00
Natural Gas | High end of range
Embedded derivatives
Sales price (dollars per barrel) | $ / MillionCubicFeet		3.60
Oman, Bolivia and the Gulf of Mexico
Embedded derivatives
Impairment and related charges			293
Gulf of Mexico
Embedded derivatives
Impairment and related charges		$ 1,200	$ 241
Algeria Oil and Gas Proved Properties
Embedded derivatives
Impairment and related charges		900
Level 2 | Domestic Onshore Unproved Acreage
Embedded derivatives
Impairment and related charges		$ 4,300
Level 3 | Measurement Input, Weighted Average Cost of Capital
Embedded derivatives
Discount rate		10.00%	10.00%
Recurring | Accrued liabilities
Embedded derivatives
Netting and Collateral		$ 0	$ 0	$ 0
Recurring | Accrued liabilities | Total Fair Value
Embedded derivatives
Embedded derivatives		83	83	40
Recurring | Accrued liabilities | Level 1
Embedded derivatives
Embedded derivatives		0	0	0
Recurring | Accrued liabilities | Level 2
Embedded derivatives
Embedded derivatives		83	83	40
Recurring | Accrued liabilities | Level 3
Embedded derivatives
Embedded derivatives		0	0	0
Recurring | Deferred credits and other liabilities - other
Embedded derivatives
Netting and Collateral		0	0	0
Recurring | Deferred credits and other liabilities - other | Total Fair Value
Embedded derivatives
Embedded derivatives		41	41	49
Recurring | Deferred credits and other liabilities - other | Level 1
Embedded derivatives
Embedded derivatives		0	0	0
Recurring | Deferred credits and other liabilities - other | Level 2
Embedded derivatives
Embedded derivatives		41	41	49
Recurring | Deferred credits and other liabilities - other | Level 3
Embedded derivatives
Embedded derivatives		0	0	0
Ghana Assets
Embedded derivatives
Impairment and related charges		1,400	1,400
Ghana Assets | Discontinued Operations, Held-for-sale
Embedded derivatives
Impairment and related charges	$ 1,400	2,200
Impairment and related charges, net of tax		1,400
Oil and gas segment
Embedded derivatives
Impairment and related charges		$ 6,400	$ 581
Midstream And Marketing | Anadarko
Embedded derivatives
Goodwill				$ 1,200