Retirement Plans and Other Retiree Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Retiree Benefits
Components of net periodic benefit cost
Service cost	$ 5	$ 3	$ 11	$ 7
Interest cost	8	9	19	20
Expected return on plan assets	(1)	0	(1)	(1)
Amortization of actuarial loss (gain)	6	3	11	5
Net periodic benefit cost	18	15	40	31
United States | Pension Benefits
Components of net periodic benefit cost
Service cost	0	0	0	0
Interest cost	18	23	37	46
Expected return on plan assets	(27)	(24)	(54)	(49)
Amortization of actuarial loss (gain)	13	12	24	25
Net periodic benefit cost	4	11	7	22
Voluntary benefit plan contribution			0	102
International | Pension Benefits
Components of net periodic benefit cost
Service cost	3	3	7	7
Interest cost	4	5	9	10
Expected return on plan assets	(5)	(4)	(9)	(9)
Amortization of actuarial loss (gain)	4	3	5	5
Net periodic benefit cost	$ 6	$ 7	$ 12	$ 13