Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pension Benefits
Net Periodic Benefit Cost
Net Periodic Other Benefit Costs	$ 280	$ 280	$ 550	$ 539
Pension Benefits | United States
Net Periodic Benefit Cost
Service cost	122	124	244	247
Interest cost	92	94	183	188
Expected return on plan assets	(149)	(180)	(298)	(361)
Amortization of prior service credits	(1)	(2)	(2)	(4)
Amortization of actuarial losses	85	83	170	167
Settlement losses	78	81	156	162
Net Periodic Other Benefit Costs	227	200	453	399
Pension Benefits | International
Net Periodic Benefit Cost
Service cost	39	43	76	83
Interest cost	57	63	110	130
Expected return on plan assets	(59)	(61)	(117)	(123)
Amortization of prior service credits	3	6	6	10
Amortization of actuarial losses	13	12	22	23
Settlement losses	0	17	0	17
Net Periodic Other Benefit Costs	53	80	97	140
Other Benefits
Net Periodic Benefit Cost
Service cost	8	15	16	30
Interest cost	25	32	48	64
Amortization of prior service credits	(7)	4	(14)	7
Amortization of actuarial losses	(2)	5	(3)	10
Net Periodic Other Benefit Costs	$ 24	$ 56	$ 47	$ 111