Pension and Other Post-Retirement Benefits - Schedule of Net Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension Benefits
Components of net periodic pension expense (credit):(1)
Interest cost	$ 1	$ 1	$ 4	$ 3
Expected return on plan assets	(4)	(4)	(11)	(12)
Amortization of net actuarial loss	2	1	5	2
Net periodic (credit) expense	(1)	(2)	(2)	(7)
Post Retirement Benefits (2)
Components of net periodic pension expense (credit):(1)
Interest cost	0	0	0	0
Expected return on plan assets	0	0	0	0
Amortization of net actuarial loss	0	0	0	0
Net periodic (credit) expense	$ 0	$ 0	$ 0	$ 0