Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net Periodic Benefit Cost
Net Periodic Other Benefit Costs	$ 270	$ 259
U.S. [Member]
Net Periodic Benefit Cost
Service cost	122	123
Interest cost	91	94
Expected return on plan assets	(149)	(181)
Amortization of prior service credits	(1)	(2)
Amortization of actuarial losses	85	84
Settlement losses	78	81
Net Periodic Other Benefit Costs	226	199
International [Member]
Net Periodic Benefit Cost
Service cost	37	40
Interest cost	53	67
Expected return on plan assets	(58)	(62)
Amortization of prior service credits	3	4
Amortization of actuarial losses	9	11
Settlement losses	0	0
Net Periodic Other Benefit Costs	44	60
Other Benefits [Member]
Net Periodic Benefit Cost
Service cost	8	15
Interest cost	23	32
Amortization of prior service credits	(7)	3
Amortization of actuarial losses	(1)	5
Net Periodic Other Benefit Costs	$ 23	$ 55