Retirement Benefits and Trusteed Assets (Pension Plan - Other Changes in Plan Assets and Benefit Obligations recognized in Reg Assets and OCI) (Details) - Pension plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income (loss)
Net actuarial (gain) loss	$ 156	$ (376)
Amortization of net actuarial loss and settlements	(209)	(209)
Prior service cost	0	4
Amortization of prior service (cost) credit	1	(3)
Total recognized in Regulatory assets and Other comprehensive income (loss)	(52)	(584)
Total recognized in net periodic pension cost, Regulatory assets, and Other comprehensive income (loss)	$ 71	$ (445)