Retirement Plans and Other Retiree Benefits - Summary of Net Periodic Benefit Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Retiree Benefit Plans
Components of Net Periodic Benefit Cost
Service cost	$ 15	$ 16	$ 13
Interest cost	41	38	40
Annual ESOP allocation	0	0	0
Expected return on plan assets	(3)	(2)	0
Amortization of transition and prior service costs (credits)	0	0	0
Amortization of actuarial loss	11	14	13
Net periodic benefit cost	64	66	66
Other postretirement charges	0	0	(3)
Total pension cost	$ 64	$ 66	$ 63
Weighted-Average Assumptions Used to Determine Net Periodic Benefit Cost
Discount rate	4.43%	3.80%	4.41%
Long-term rate of return on plan assets	6.60%	6.60%	6.80%
Long-term rate of compensation increase	0.00%	0.00%	0.00%
ESOP growth rate	10.00%	10.00%	10.00%
Medical cost trend rate of increase	6.00%	6.00%	6.33%
Interest Crediting Rate	0.00%	0.00%	0.00%
United States | Pension Plans
Components of Net Periodic Benefit Cost
Service cost	$ 1	$ 1	$ 1
Interest cost	90	86	94
Annual ESOP allocation	0	0	0
Expected return on plan assets	(103)	(115)	(111)
Amortization of transition and prior service costs (credits)	0	0	0
Amortization of actuarial loss	51	47	48
Net periodic benefit cost	39	19	32
Other postretirement charges	7	9	24
Total pension cost	$ 46	$ 28	$ 56
Weighted-Average Assumptions Used to Determine Net Periodic Benefit Cost
Discount rate	4.38%	3.73%	4.27%
Long-term rate of return on plan assets	6.60%	6.60%	6.80%
Long-term rate of compensation increase	3.50%	3.50%	3.50%
ESOP growth rate	0.00%	0.00%	0.00%
Medical cost trend rate of increase	0.00%	0.00%	0.00%
Interest Crediting Rate	4.26%	3.73%	4.27%
Defined Benefit Plan Disclosure, Additional Information [Abstract]
Voluntary contributions to postretirement plans	$ 113	$ 67	$ 81
International | Pension Plans
Components of Net Periodic Benefit Cost
Service cost	14	14	16
Interest cost	22	21	22
Annual ESOP allocation	0	0	0
Expected return on plan assets	(19)	(21)	(22)
Amortization of transition and prior service costs (credits)	1	0	0
Amortization of actuarial loss	9	8	10
Net periodic benefit cost	27	22	26
Other postretirement charges	1	2	4
Total pension cost	$ 28	$ 24	$ 30
Weighted-Average Assumptions Used to Determine Net Periodic Benefit Cost
Discount rate	2.80%	2.53%	2.59%
Long-term rate of return on plan assets	4.06%	4.04%	4.14%
Long-term rate of compensation increase	2.86%	2.79%	2.58%
ESOP growth rate	0.00%	0.00%	0.00%
Medical cost trend rate of increase	0.00%	0.00%	0.00%
Interest Crediting Rate	0.85%	0.85%	0.65%
Global Growth and Efficiency Program
Defined Benefit Plan Disclosure, Additional Information [Abstract]
Charges against assets	$ 76	$ 27	$ 40
Global Growth and Efficiency Program | Employee-Related Costs
Defined Benefit Plan Disclosure, Additional Information [Abstract]
Charges against assets	$ 7	$ 9	$ 21