Other Financial Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 4,463,000,000	$ 4,518,000,000
Segment Reporting Information [Line Items]
Gains on sale of nonstrategic properties	1,500,000,000	630,000,000
Company share of equity affiliates foreign currency effects	(28,000,000)	416,000,000	$ (45,000,000)
Total financing interest and debt costs	817,000,000	921,000,000	902,000,000
Less: Capitalized interest	19,000,000	173,000,000	595,000,000
Interest and debt expense	798,000,000	748,000,000	307,000,000
Research and development expenses	500,000,000	453,000,000	433,000,000
Excess of replacement cost over the carrying value of inventories (LIFO method)	4,513,000,000	5,134,000,000	3,937,000,000
LIFO profits (losses) on inventory drawdowns included in earnings	(9,000,000)	26,000,000	(5,000,000)
Foreign currency effects	(304,000,000)	611,000,000	$ (446,000,000)
Downstream
Segment Reporting Information [Line Items]
Gains on sale of nonstrategic properties	50,000,000	365,000,000
Upstream
Segment Reporting Information [Line Items]
Gains on sale of nonstrategic properties	1,450,000,000	265,000,000
Gain (loss) for impairments and other assets write-offs	10,400,000,000	$ 2,000,000,000
Unocal | Upstream
Business Acquisition [Line Items]
Goodwill	4,463,000,000
Goodwill impairment loss	$ 0