Other Comprehensive Income Information (Schedule Of Accumulated Other Comprehensive Income Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Current period change excluding amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	$ (786)	$ (1,209)
Amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	82
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	(84)	65
Amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	316	444
Current period change excluding amounts reclassified from accumulated other comprehensive income, Unrealized Change in Stock Investments	(54)
Beginning Balance, Total	(10,725)
Total change in accumulated other comprehensive income	(526)	(700)
Ending Balance, Total	(11,040)
Exxon Mobil Corporation Share After Noncontrolling Interest [Member]
Beginning Balance, Cumulative Foreign Exchange Translation Adjustment	(846)	2,410
Current period change excluding amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	(555)	(1,088)
Amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	82
Total change in accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment	(473)	(1,088)
Ending Balance, Cumulative Foreign Exchange Translation Adjustment	(1,319)	1,322
Beginning Balance, Postretirement Benefits Reserves Adjustment	(9,879)	(14,594)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	(93)	78
Amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	305	427
Total change in accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment	212	505
Ending Balance, Postretirement Benefits Reserves Adjustment	(9,667)	(14,089)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Unrealized Change in Stock Investments	(54)
Total change in accumulated other comprehensive income, Unrealized Change in Stock Investments	(54)
Ending Balance, Unrealized Change in Stock Investments	(54)
Beginning Balance, Total	(10,725)	(12,184)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Total	(702)	(1,010)
Amounts reclassified from accumulated other comprehensive income, Total	387	427
Total change in accumulated other comprehensive income	(315)	(583)
Ending Balance, Total	$ (11,040)	$ (12,767)