Operating Segments and Geographic Data - Segment Revenues (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Sales and other operating revenues	$ 46,580	$ 48,842
Oil and Gas
Segment Reporting Information [Line Items]
Sales and other operating revenues	46,580	48,842
Oil and Gas | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	60,402	59,423
Oil and Gas | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	121	109
Oil and Gas | Total All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	27	30
Oil and Gas | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	31,527	29,121
Oil and Gas | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(93)	(79)
Oil and Gas | United States | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	120	108
Oil and Gas | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(10,389)	(7,546)
Oil and Gas | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	28,875	30,302
Oil and Gas | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(1)	0
Oil and Gas | International | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	1	1
Oil and Gas | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(3,433)	(3,035)
Oil and Gas | Upstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	11,436	12,311
Oil and Gas | Upstream | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	21,950	20,819
Oil and Gas | Upstream | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	11,167	9,623
Oil and Gas | Upstream | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(7,589)	(5,902)
Oil and Gas | Upstream | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	10,783	11,196
Oil and Gas | Upstream | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(2,925)	(2,606)
Oil and Gas | Downstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	35,117	36,501
Oil and Gas | Downstream | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	38,331	38,495
Oil and Gas | Downstream | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	20,240	19,390
Oil and Gas | Downstream | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(2,707)	(1,565)
Oil and Gas | Downstream | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	18,091	19,105
Oil and Gas | Downstream | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	$ (507)	$ (429)