Operating Segments and Geographic Data - Segment Revenues (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Sales and other operating revenues	$ 52,314	$ 31,076
Oil and Gas
Segment Reporting Information [Line Items]
Sales and other operating revenues	52,314	31,076
Oil and Gas | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	64,279	37,041
Oil and Gas | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	83	24
Oil and Gas | Total All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	16	24
Oil and Gas | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	31,170	16,669
Oil and Gas | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(67)	0
Oil and Gas | United States | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	83	24
Oil and Gas | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(7,985)	(3,321)
Oil and Gas | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	33,109	20,372
Oil and Gas | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	0	0
Oil and Gas | International | All Other
Segment Reporting Information [Line Items]
Sales and other operating revenues	0	0
Oil and Gas | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(3,980)	(2,644)
Oil and Gas | Upstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	14,250	9,351
Oil and Gas | Upstream | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	24,818	14,581
Oil and Gas | Upstream | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	11,316	5,791
Oil and Gas | Upstream | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(6,919)	(2,855)
Oil and Gas | Upstream | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	13,502	8,790
Oil and Gas | Upstream | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(3,649)	(2,375)
Oil and Gas | Downstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	38,048	21,701
Oil and Gas | Downstream | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	39,378	22,436
Oil and Gas | Downstream | United States | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	19,771	10,854
Oil and Gas | Downstream | United States | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	(999)	(466)
Oil and Gas | Downstream | International | Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues	19,607	11,582
Oil and Gas | Downstream | International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues	$ (331)	$ (269)