Other Comprehensive Income Information (Schedule Of Accumulated Other Comprehensive Income Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Cumulative Translation Adjustment Summary [Roll Forward]
Current period change excluding amounts reclassified from accumulated other comprehensive income	$ 302	$ (1,267)
Postretirement Benefits Reserves Adjustment [Roll Forward]
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	(34)	(42)
Amounts reclassified from accumulated other comprehensive income	23	9
Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(14,619)
Balance at end of period	(14,338)
Exxon Mobil Corporation Share After Noncontrolling Interest
Cumulative Translation Adjustment Summary [Roll Forward]
Beginning Balance, Cumulative Foreign Exchange Translation Adjustment	(16,166)	(13,056)
Current period change excluding amounts reclassified from accumulated other comprehensive income	295	(1,138)
Amounts reclassified from accumulated other comprehensive income	0	0
Total change in accumulated other comprehensive income	295	(1,138)
Ending Balance, Cumulative Foreign Exchange Translation Adjustment	(15,871)	(14,194)
Net investment hedge gain/(loss), net of taxes	(99)	84
Postretirement Benefits Reserves Adjustment [Roll Forward]
Beginning Balance, Postretirement Benefits Reserves Adjustment	1,547	1,067
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	(36)	(48)
Amounts reclassified from accumulated other comprehensive income	22	6
Total change in accumulated other comprehensive income	(14)	(42)
Ending Balance, Postretirement Benefits Reserves Adjustment	1,533	1,025
Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(14,619)	(11,989)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Total	259	(1,186)
Amounts reclassified from accumulated other comprehensive income	22	6
Total change in accumulated other comprehensive income	281	(1,180)
Balance at end of period	$ (14,338)	$ (13,169)