v3.3.1.900
Other Comprehensive Income Information (Schedule of Accumulated Other Comprehensive Income Information) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Current period change excluding amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment $ (9,303) $ (5,847) $ (3,620)
Amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment (14) 152 (23)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment 2,358 (4,262) 3,174
Amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment 1,448 1,111 1,820
Current period change excluding amounts reclassified from accumulated other comprehensive income, Unrealized Change in Stock Investments 33 (63)  
Amounts reclassified from accumulated other comprehensive income, Unrealized Change in Stock Investments 27 3  
Beginning Balance, Total (18,957)    
Ending Balance, Total (23,511) (18,957)  
Exxon Mobil Corporation Share After Noncontrolling Interest [Member]      
Beginning Balance, Cumulative Foreign Exchange Translation Adjustment (5,952) (846) 2,410
Current period change excluding amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment (8,204) (5,258) (3,233)
Amounts reclassified from accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment (14) 152 (23)
Total change in accumulated other comprehensive income, Cumulative Foreign Exchange Translation Adjustment (8,218) (5,106) (3,256)
Ending Balance, Cumulative Foreign Exchange Translation Adjustment (14,170) (5,952) (846)
Beginning Balance, Postretirement Benefits Reserves Adjustment (12,945) (9,879) (14,594)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment 2,202 (4,132) 2,963
Amounts reclassified from accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment 1,402 1,066 1,752
Total change in accumulated other comprehensive income, Postretirement Benefits Reserves Adjustment 3,604 (3,066) 4,715
Ending Balance, Postretirement Benefits Reserves Adjustment (9,341) (12,945) (9,879)
Beginning Balance, Unrealized Change in Stock Investments (60)    
Current period change excluding amounts reclassified from accumulated other comprehensive income, Unrealized Change in Stock Investments 33 (63)  
Amounts reclassified from accumulated other comprehensive income, Unrealized Change in Stock Investments 27 3  
Total change in accumulated other comprehensive income, Unrealized Change in Stock Investments 60 (60)  
Ending Balance, Unrealized Change in Stock Investments   (60)  
Beginning Balance, Total (18,957) (10,725) (12,184)
Current period change excluding amounts reclassified from accumulated other comprehensive income, Total (5,969) (9,453) (270)
Amounts reclassified from accumulated other comprehensive income, Total 1,415 1,221 1,729
Total other comprehensive income (4,554) (8,232) 1,459
Ending Balance, Total $ (23,511) $ (18,957) $ (10,725)