Properties, Plant and Equipment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Properties, Plant and Equipment
Gross Investment at Cost	[1]	$ 340,277	$ 327,289	$ 296,433
Net Investment	[1]	188,396	183,173	164,829
Additions at Cost	[1],[2]	28,002	36,332	38,122
Depreciation Expense	[1],[3]	21,037	16,793	14,186
United States [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	122,550	125,163	117,364
Net Investment	[1]	56,791	59,960	56,506
Additions at Cost	[1],[2]	7,639	10,857	10,063
Depreciation Expense	[1],[3]	9,862	6,693	5,478
International [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	217,727	202,126	179,069
Net Investment	[1]	131,605	123,213	108,323
Additions at Cost	[1],[2]	20,363	25,475	28,059
Depreciation Expense	[1],[3]	11,175	10,100	8,708
Upstream [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	302,243	289,487	259,178
Net Investment	[1]	170,584	164,790	145,931
Additions at Cost	[1],[2]	26,579	34,608	35,571
Depreciation Expense	[1],[3]	19,348	14,815	12,748
Upstream [Member] | United States [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	93,848	96,850	89,555
Net Investment	[1]	43,125	45,864	41,831
Additions at Cost	[1],[2]	6,586	9,688	8,188
Depreciation Expense	[1],[3]	8,545	5,127	4,412
Upstream [Member] | International [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	208,395	192,637	169,623
Net Investment	[1]	127,459	118,926	104,100
Additions at Cost	[1],[2]	19,993	24,920	27,383
Depreciation Expense	[1],[3]	10,803	9,688	8,336
Downstream [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	32,379	31,974	31,710
Net Investment	[1]	14,897	15,238	15,620
Additions at Cost	[1],[2]	1,061	1,118	1,807
Depreciation Expense	[1],[3]	1,233	1,282	1,140
Downstream [Member] | United States [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	23,202	22,640	22,407
Net Investment	[1]	10,807	11,019	11,481
Additions at Cost	[1],[2]	696	588	1,154
Depreciation Expense	[1],[3]	878	886	780
Downstream [Member] | International [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	9,177	9,334	9,303
Net Investment	[1]	4,090	4,219	4,139
Additions at Cost	[1],[2]	365	530	653
Depreciation Expense	[1],[3]	355	396	360
All Other Segments [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	5,655	5,828	5,545
Net Investment	[1]	2,915	3,145	3,278
Additions at Cost	[1],[2]	362	606	744
Depreciation Expense	[1],[3]	456	696	298
All Other Segments [Member] | United States [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	5,500	5,673	5,402
Net Investment	[1]	2,859	3,077	3,194
Additions at Cost	[1],[2]	357	581	721
Depreciation Expense	[1],[3]	439	680	286
All Other Segments [Member] | International [Member]
Properties, Plant and Equipment
Gross Investment at Cost	[1]	155	155	143
Net Investment	[1]	56	68	84
Additions at Cost	[1],[2]	5	25	23
Depreciation Expense	[1],[3]	$ 17	$ 16	$ 12

[1] Other than the United States, Australia and Nigeria, no other country accounted for 10 percent or more of the company’s net properties, plant and equipment (PP&E) in 2015. Australia had $49,205, $41,012 and $31,464 in 2015, 2014, and 2013, respectively. Nigeria had PP&E of $18,773, $19,214 and $18,429 for 2015, 2014 and 2013, respectively.

[2] Net of dry hole expense related to prior years’ expenditures of $1,573, $371 and $89 in 2015, 2014 and 2013, respectively.

[3] Depreciation expense includes accretion expense of $715, $882 and $627 in 2015, 2014 and 2013, respectively