Financial Instruments and Derivatives (Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Realized and Unrealized Before-Tax Gain / (Loss) on Derivative Instruments Recognized in the Consolidated Statement of Income
Revenues	$ 83,130	$ 83,083
Crude oil and product purchases	(46,788)	(47,601)
Not Designated as Hedging Instrument
Realized and Unrealized Before-Tax Gain / (Loss) on Derivative Instruments Recognized in the Consolidated Statement of Income
Revenues	19	(792)
Crude oil and product purchases	2	3
Total	$ 21	$ (789)