Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net Periodic Benefit Cost
Net Periodic Other Benefit Costs	$ 280	$ 289	$ 539	$ 567
U.S. [Member]
Net Periodic Benefit Cost
Service cost	124	134	247	269
Interest cost	94	125	188	251
Expected return on plan assets	(180)	(196)	(361)	(392)
Amortization of prior service credits	(2)	(2)	(4)	(4)
Amortization of actuarial losses	83	89	167	178
Settlement losses	81	54	162	108
Net Periodic Other Benefit Costs	200	204	399	410
International [Member]
Net Periodic Benefit Cost
Service cost	43	49	83	94
Interest cost	63	72	130	141
Expected return on plan assets	(61)	(65)	(123)	(130)
Amortization of prior service credits	6	6	10	11
Amortization of actuarial losses	12	23	23	41
Settlement losses	17	0	17	0
Net Periodic Other Benefit Costs	80	85	140	157
Other Benefits [Member]
Net Periodic Benefit Cost
Service cost	15	18	30	36
Interest cost	32	37	64	75
Amortization of prior service credits	4	4	7	7
Amortization of actuarial losses	5	8	10	17
Net Periodic Other Benefit Costs	$ 56	$ 67	$ 111	$ 135