Pension, Savings and Other Postretirement Benefit Plans - Defined Benefit Pension Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
U.S.
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 1	$ 1	$ 2	$ 2
Interest cost	42	39	86	79
Expected return on plan assets	(55)	(54)	(111)	(109)
Amortization of net losses	28	28	56	56
Net periodic pension cost	16	14	33	28
Net curtailments/settlements/termination benefits	0	3	0	3
Total defined benefit pension cost	16	17	33	31
Non-U.S.
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	7	7	14	14
Interest cost	17	17	35	35
Expected return on plan assets	(15)	(18)	(30)	(36)
Amortization of prior service cost	1	0	1	0
Amortization of net losses	7	8	14	15
Net periodic pension cost	17	14	34	28
Net curtailments/settlements/termination benefits	(1)	0	0	0
Total defined benefit pension cost	$ 16	$ 14	$ 34	$ 28