Consolidated Statement Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statement Of Comprehensive Income [Abstract]
Net income including noncontrolling interests	$ 21,421	$ 19,848	$ 8,375
Other comprehensive income (net of income taxes)
Foreign exchange translation adjustment	(5,077)	5,352	(174)
Adjustment for foreign exchange translation (gain)/loss included in net income	196	234
Postretirement benefits reserves adjustment (excluding amortization)	280	(219)	493
Amortization and settlement of postretirement benefits reserves adjustment included in net periodic benefit costs	931	1,165	1,086
Total other comprehensive income	(3,670)	6,532	1,405
Comprehensive income including noncontrolling interests	17,751	26,380	9,780
Comprehensive income attributable to noncontrolling interests	174	693	668
Comprehensive income attributable to ExxonMobil	$ 17,577	$ 25,687	$ 9,112