Pensions Benefit Plans and Other Postretirement Benefits - Changes in the Benefit Obligation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefit Plans | U.S.
Changes in the pension and postretirement benefit obligations
Obligations at beginning of year	$ 1,650	$ 1,956
Change in benefit obligations:
Service cost	14	14	$ 15
Interest cost	59	78	90
Actuarial (gain) loss, including the effect of change in discount rates	(108)	123
Settlements	(114)	(393)
Benefit payments	(91)	(128)
Other	3
Net change in benefit obligations	(237)	(306)
Obligations at end of year	1,413	1,650	1,956
Pension Benefit Plans | Non-U.S.
Changes in the pension and postretirement benefit obligations
Obligations at beginning of year	1,148	1,235
Change in benefit obligations:
Service cost	15	15	16
Interest cost	32	40	44
Actuarial (gain) loss, including the effect of change in discount rates	(23)	(15)
Settlements	(35)	(171)
Participant contributions	2	1
Benefit payments	(51)	(60)
Foreign currency translation	(64)	103
Other	(2)
Net change in benefit obligations	(126)	(87)
Obligations at end of year	1,022	1,148	1,235
Other Postretirement Benefits | U.S.
Changes in the pension and postretirement benefit obligations
Obligations at beginning of year	89	92
Change in benefit obligations:
Interest cost	3	4	4
Actuarial (gain) loss, including the effect of change in discount rates	(9)
Benefit payments	(9)	(7)
Net change in benefit obligations	(15)	(3)
Obligations at end of year	74	89	92
Other Postretirement Benefits | Non-U.S.
Changes in the pension and postretirement benefit obligations
Obligations at beginning of year	89	81
Change in benefit obligations:
Service cost	1	1	1
Interest cost	3	3	3
Actuarial (gain) loss, including the effect of change in discount rates	(4)	1
Benefit payments	(2)	(2)
Foreign currency translation	(7)	5
Net change in benefit obligations	(9)	8
Obligations at end of year	$ 80	$ 89	$ 81