Retirement Plans and Other Retiree Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Retiree Benefits
Components of net periodic benefit cost
Service cost	$ 6	$ 4
Interest cost	11	11
Expected return on plan assets	0	(1)
Amortization of actuarial loss (gain)	5	2
Net periodic benefit cost	22	16
United States | Pension Benefits
Components of net periodic benefit cost
Service cost	0	0
Interest cost	19	23
Expected return on plan assets	(27)	(26)
Amortization of actuarial loss (gain)	11	13
Net periodic benefit cost	3	10
Voluntary benefit plan contribution	0	102
International | Pension Benefits
Components of net periodic benefit cost
Service cost	4	4
Interest cost	5	5
Expected return on plan assets	(4)	(5)
Amortization of actuarial loss (gain)	1	2
Net periodic benefit cost	$ 6	$ 6