Employee Retirement Benefits - Unrecognized Amounts (Details) - Pension Benefits [Member] - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Components of AOCI:
Unrecognized prior service benefit	$ 1	$ 2
Unrecognized losses	(91)	41
Total	(90)	43
Tax effects on components of AOCI [Abstract]
Tax expense (benefit) related to unrecognized prior service benefit (cost)	0	1
Tax expense (benefit) related to unrecognized gain (loss)	(33)	7
Unrecognized amounts included in regulatory assets (liabilities) [Abstract]
Unrecognized prior service cost (benefit)	2	(1)
Unrecognized losses (gains)	277	(80)
Total	$ 279	$ (81)