Pension and Other Postretirement Benefit Plans - Summary of Components of Net Periodic Pension Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 1	$ 0	$ 3
Interest cost	2	3	3	6
Expected return on plan assets	0	0	0	0
Amortization:
Actuarial loss	0	0	0	0
Prior service credit	(12)	(2)	(23)	(4)
Settlement and curtailment (gain) loss	0	(4)	0	(4)
Net periodic benefit cost (credit)	(10)	(2)	(20)	1
United States Pension Benefits | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	1
Interest cost	19	24	38	49
Expected return on plan assets	(40)	(41)	(79)	(82)
Amortization:
Actuarial loss	18	16	35	31
Prior service credit	0	0	0	0
Settlement and curtailment (gain) loss	3	0	3	0
Net periodic benefit cost (credit)	0	(1)	(2)	(1)
Foreign Pension Benefits | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	1	3	3
Interest cost	3	5	7	9
Expected return on plan assets	(8)	(7)	(17)	(15)
Amortization:
Actuarial loss	5	3	10	6
Prior service credit	0	0	0	0
Settlement and curtailment (gain) loss	0	0	0	0
Net periodic benefit cost (credit)	$ 2	$ 2	$ 3	$ 3