Employee Benefits (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net Periodic Benefit Cost
Net Periodic Benefit Costs		$ 310	$ 221	$ 877	$ 645
U.S. [Member]
Net Periodic Benefit Cost
Service cost		135	113	404	338
Interest cost		125	124	376	371
Expected return on plan assets		(195)	(197)	(587)	(591)
Amortization of prior service credits		(3)	(3)	(7)	(7)
Amortization of actuarial losses		89	52	267	157
Settlement losses (gains)		87	48	195	114
Net Periodic Benefit Costs		238	137	648	382
International [Member]
Net Periodic Benefit Cost
Service cost		46	46	140	143
Interest cost		68	84	209	257
Expected return on plan assets		(66)	(75)	(196)	(227)
Amortization of prior service credits		5	6	16	16
Amortization of actuarial losses		19	23	60	74
Net Periodic Benefit Costs		72	84	229	263
Other Benefits [Member]
Net Periodic Benefit Cost
Service cost	[1]	18	13	54	38
Interest cost	[1]	37	37	112	112
Amortization of prior service credits	[1]	3	3	10	10
Amortization of actuarial losses	[1]	9	2	26	5
Net Periodic Benefit Costs		$ 67	$ 55	$ 202	$ 165

[1] Includes costs for U.S. and international OPEB plans. Obligations for plans outside the United States are not significant relative to the company’s total OPEB obligation.