Pensions Benefit Plans and Other Postretirement Benefits - Components of Net Periodic Pension and Postretirement Cost (Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortization:
Settlement charges	$ 26	$ 74	$ 218
Pension Benefit Plans
Amortization:
Accumulated benefit obligation	2,622	2,379
U.S. | Pension Benefit Plans
Components of net periodic pension cost
Service cost	12	14	14
Interest cost	58	59	78
Expected asset return	(86)	(98)	(128)
Amortization:
Amortization of actuarial loss	41	51	57
Net periodic pension cost	25	26	21
Settlement charges	22	61
Settlement cost	17	61	176
Annuity contract purchase for settlement of pension obligation		94	369
U.S. | Other Postretirement Benefits
Components of net periodic pension cost
Interest cost	4	3	4
Amortization:
Amortization of actuarial loss	1	2	2
Prior service cost	(8)	(7)	(8)
Net amortization	(7)	(5)	(6)
Net periodic pension cost	(3)	(2)	(2)
Non-U.S. | Pension Benefit Plans
Components of net periodic pension cost
Service cost	12	15	15
Interest cost	33	32	40
Expected asset return	(48)	(52)	(63)
Amortization:
Amortization of actuarial loss	10	11	16
Net periodic pension cost	7	6	8
Settlement charges	9	13
Non-U.S. | Other Postretirement Benefits
Components of net periodic pension cost
Service cost	1	1	1
Interest cost	3	3	3
Amortization:
Net periodic pension cost	4	4	4
Canadian Pension Plans | Pension Benefit Plans
Amortization:
Settlement cost			27
Annuity contract purchase for settlement of pension obligation			123
Pension Plan of the United Kingdom | Pension Benefit Plans
Amortization:
Settlement cost	7	$ 13	$ 15
Pension Plan of Mexico | Pension Benefit Plans
Amortization:
Settlement cost	$ 2