Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net Periodic Benefit Cost
Net Periodic Other Benefit Costs	$ 341	$ 310	$ 880	$ 877
U.S. [Member]
Net Periodic Benefit Cost
Service cost	123	135	370	404
Interest cost	95	125	283	376
Expected return on plan assets	(181)	(195)	(542)	(587)
Amortization of prior service credits	(2)	(3)	(6)	(7)
Amortization of actuarial losses	84	89	251	267
Settlement losses	162	87	324	195
Net Periodic Other Benefit Costs	281	238	680	648
International [Member]
Net Periodic Benefit Cost
Service cost	37	46	120	140
Interest cost	68	68	198	209
Expected return on plan assets	(61)	(66)	(184)	(196)
Amortization of prior service credits	1	5	11	16
Amortization of actuarial losses	14	19	37	60
Settlement losses	1	0	18	0
Net Periodic Other Benefit Costs	60	72	200	229
Other Benefits [Member]
Net Periodic Benefit Cost
Service cost	15	18	45	54
Interest cost	32	37	96	112
Amortization of prior service credits	3	3	10	10
Amortization of actuarial losses	5	9	15	26
Net Periodic Other Benefit Costs	$ 55	$ 67	$ 166	$ 202