Pension And Other Postretirement Benefits (Summary Of The Change In Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	$ 784	$ (504)	$ 4,799
(Charge)/credit to income tax (see Note 4)	(208)	180	(1,236)
(Charge)/credit to investment in equity companies	24	16	235
(Charge)/credit to other comprehensive income including noncontrolling interests, after tax	600	(308)	3,798
Charge/(credit) to equity of noncontrolling interests	(120)	54	(212)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	(86)	(4)	1,881
Exxon Mobil Corporation Share After Noncontrolling Interest [Member]
Defined Benefit Plan Disclosure [Line Items]
Total change in accumulated other comprehensive income	480	(254)	3,586
United States
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	82	141	939
Pension Benefits - Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Total (charge)/credit to other comprehensive income, before tax	$ 788	$ (641)	$ 1,979