Pension, Savings and Other Postretirement Benefit Plans - Defined Benefit Pension Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
U.S.
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 1	$ 1	$ 3	$ 3
Interest cost	39	41	120	123
Expected return on plan assets	(60)	(64)	(181)	(191)
Amortization of net losses	27	28	83	82
Net periodic pension cost	7	6	25	17
Net curtailments and settlements	24	0	25	0
Total defined benefit pension cost	31	6	50	17
Non-U.S.
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	8	7	23	22
Interest cost	18	20	53	61
Expected return on plan assets	(20)	(21)	(59)	(67)
Amortization of net losses	8	7	24	21
Net periodic pension cost	14	13	41	37
Net curtailments and settlements	2	0	2	13
Total defined benefit pension cost	$ 16	$ 13	$ 43	$ 50