Retirement Benefits (Funded Status Of Benefit Plans And Amounts Included In Regulatory Assets And OCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in plan assets:
Funded status – deficiency (surplus)	$ (377)	$ (717)
Accrued benefit cost (asset) at December 31	(377)	(717)
Amounts recognized in the balance sheet consist of:
Noncurrent asset	(411)	(756)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation at end of year	3,911	5,174
Change in benefit obligation:
Net benefit obligation at beginning of year	5,457	5,510
Service cost	128	134	$ 110
Interest cost	163	152	174
Participant contributions	0	0
Actuarial gain	(1,425)	(82)
Benefits paid	(262)	(257)
Net benefit obligation at end of year	4,061	5,457	5,510
Change in plan assets:
Fair value of plan assets at beginning of year	5,745	5,510
Actual return on plan assets	(1,461)	432
Employer contributions	5	60	52
Participant contributions	0	0
Benefits paid	(262)	(257)
Fair value of plan assets at end of year	4,027	5,745	5,510
Funded status – deficiency (surplus)	34	(288)
Accrued benefit cost (asset) at December 31	34	(288)
Amounts recognized in the balance sheet consist of:
Noncurrent asset	0	(327)
Liability, Defined Benefit Plan, Current	3	2
Liability, Defined Benefit Plan, Noncurrent	31	37
Amounts recognized in regulatory assets or liabilities consist of:
Net actuarial gain	(107)	(415)
Prior service credit	0	0
Amounts recognized in accumulated OCI (pretax) consist of:
Net actuarial (gain) loss	15	(8)
Total	(92)	(423)
Postretirement Benefits
Change in benefit obligation:
Net benefit obligation at beginning of year	1,129	1,204
Service cost	20	23	19
Interest cost	34	33	39
Participant contributions	8	9
Actuarial gain	(289)	(80)
Benefits paid	(64)	(60)
Net benefit obligation at end of year	838	1,129	1,204
Change in plan assets:
Fair value of plan assets at beginning of year	1,558	1,453
Actual return on plan assets	(255)	154
Employer contributions	2	2	2
Participant contributions	8	9
Benefits paid	(64)	(60)
Fair value of plan assets at end of year	1,249	1,558	$ 1,453
Funded status – deficiency (surplus)	(411)	(429)
Accrued benefit cost (asset) at December 31	(411)	(429)
Amounts recognized in the balance sheet consist of:
Noncurrent asset	(411)	(429)
Liability, Defined Benefit Plan, Current	0	0
Liability, Defined Benefit Plan, Noncurrent	0	0
Amounts recognized in regulatory assets or liabilities consist of:
Net actuarial gain	(268)	(343)
Prior service credit	(29)	(33)
Amounts recognized in accumulated OCI (pretax) consist of:
Net actuarial (gain) loss	(4)	1
Total	$ (301)	$ (375)