Employee Retirement Benefits - Net Periodic Income Cost Regulatory Assets (Details) - Pension Benefits [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost Recognized In Regulatory Assets Liabilities	$ 2	$ (1)
Unrecognized losses (gains)	375	(226)
Amortization of prior service benefit	1	0
Amortization Of Unrecognized Losses Recognized In Regulatory Assets Liabilities	(18)	(16)
Total	$ 360	$ (243)