Postretirement Benefit Plans - Expense Related to Defined Benefit and Retiree Health Care Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
U.S. | Defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5
Interest cost	9	9
Expected return on plan assets	(9)	(11)
Recognized net actuarial loss	2	4
Amortization of prior service credit	0	0
Net periodic benefit costs	6	7
Settlement losses	3	2
Total, including other postretirement losses	9	9
U.S. | Retiree health care plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	3	4
Expected return on plan assets	(4)	(4)
Recognized net actuarial loss	0	1
Amortization of prior service credit	0	(1)
Net periodic benefit costs	0	1
Settlement losses	0	0
Total, including other postretirement losses	$ 0	$ 1
Defined Benefit Plan, Sponsor Location [Extensible List]	country:US	country:US
Non-U.S. | Defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 9
Interest cost	11	12
Expected return on plan assets	(21)	(17)
Recognized net actuarial loss	7	5
Amortization of prior service credit	0	0
Net periodic benefit costs	5	9
Settlement losses	1	0
Total, including other postretirement losses	$ 6	$ 9