Defined Benefit Postretirement Plans and Defined Contribution Plan - Fair Value of Defined Benefit Pension Plan Assets (Details) - Recurring - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 161	$ 192
Plan assets before comingled funds	45	50
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	8	(1)
Common stock
Defined Benefit Plan Disclosure [Line Items]
Plan assets	22	28
Private equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets	5	7
Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets	10	16
Commingled funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	116	142
Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	30	27
Plan assets before comingled funds	30	27
Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	8	(1)
Level 1 | Common stock
Defined Benefit Plan Disclosure [Line Items]
Plan assets	22	28
Level 1 | Private equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 | Commingled funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Plan assets before comingled funds	0	0
Level 2 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 | Common stock
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 | Private equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 | Commingled funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	15	23
Plan assets before comingled funds	15	23
Level 3 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 | Common stock
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 | Private equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets	5	7
Level 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets	10	16
Level 3 | Commingled funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 0	$ 0