Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Settlements	$ 3	$ 3	$ 7	$ 9
Pension benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	3	3
Interest cost	13	12	38	36
Expected return on plan assets	(20)	(23)	(61)	(69)
Recognized net actuarial loss	12	14	37	43
Settlements	3	3	7	9
Net periodic cost (benefit)	9	7	24	22
Other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	1
Interest cost	1	1	3	4
Recognized net actuarial loss	0	1	1	1
Amortization of prior service benefit	(2)	(3)	(7)	(7)
Net periodic cost (benefit)	$ (1)	$ (1)	$ (2)	$ (1)