Operating Segments and Geographic Data - Segment Revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Sales and other operating revenues	$ 48,926	$ 51,922	$ 145,080	$ 147,980
Oil and Gas
Segment Reporting Information [Line Items]
Sales and other operating revenues	48,926	51,922	145,080	147,980
Oil and Gas | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	61,854	64,838	186,030	182,669
Oil and Gas | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	139	150	413	415
Oil and Gas | Total All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	27	32	87	98
Oil and Gas | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	31,035	33,176	95,484	91,463
Oil and Gas | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(111)	(117)	(324)	(315)
Oil and Gas | United States | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	138	149	411	413
Oil and Gas | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(9,975)	(9,192)	(30,960)	(25,010)
Oil and Gas | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	30,819	31,662	90,546	91,206
Oil and Gas | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(1)	(1)	(2)	(2)
Oil and Gas | International | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	1	1	2	2
Oil and Gas | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(2,953)	(3,724)	(9,990)	(9,679)
Oil and Gas | Upstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	11,883	10,858	33,865	33,314
Oil and Gas | Upstream | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	22,060	20,911	65,518	60,361
Oil and Gas | Upstream | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	10,730	10,278	33,184	28,656
Oil and Gas | Upstream | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(7,432)	(6,797)	(22,911)	(18,766)
Oil and Gas | Upstream | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	11,330	10,633	32,334	31,705
Oil and Gas | Upstream | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(2,745)	(3,256)	(8,742)	(8,281)
Oil and Gas | Downstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	37,016	41,032	111,128	114,568
Oil and Gas | Downstream | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	39,655	43,777	120,099	121,893
Oil and Gas | Downstream | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	20,167	22,749	61,889	62,394
Oil and Gas | Downstream | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(2,432)	(2,278)	(7,725)	(5,929)
Oil and Gas | Downstream | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	19,488	21,028	58,210	59,499
Oil and Gas | Downstream | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	$ (207)	$ (467)	$ (1,246)	$ (1,396)