Retirement Benefits (Funded Status Of Benefit Plans And Amounts Included In Regulatory Assets And OCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in plan assets:
Funded status – surplus	$ (717)	$ (249)
Accrued benefit asset at December 31	(717)	(249)
Amounts recognized in the balance sheet consist of:
Noncurrent asset	(756)	(288)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation at end of year	5,174	5,213
Change in benefit obligation:
Net benefit obligation at beginning of year	5,510	4,967
Service cost	134	110	$ 88
Interest cost	152	174	187
Participant contributions	0	0
Actuarial (gain) loss	(82)	508
Benefits paid	(257)	(249)
Net benefit obligation at end of year	5,457	5,510	4,967
Change in plan assets:
Fair value of plan assets at beginning of year	5,510	4,564
Actual return on plan assets	432	1,143
Employer contributions	60	52	23
Participant contributions	0	0
Benefits paid	(257)	(249)
Fair value of plan assets at end of year	5,745	5,510	4,564
Funded status – surplus	(288)	0
Accrued benefit asset at December 31	(288)	0
Amounts recognized in the balance sheet consist of:
Noncurrent asset	(327)	(39)
Liability, Defined Benefit Plan, Current	2	2
Liability, Defined Benefit Plan, Noncurrent	37	37
Amounts recognized in regulatory assets consist of:
Net actuarial gain	(415)	(138)
Prior service credit	0	0
Amounts recognized in accumulated OCI (pretax) consist of:
Net actuarial (gain) loss	(8)	5
Total	(423)	(133)
Postretirement Benefits
Change in benefit obligation:
Net benefit obligation at beginning of year	1,204	1,110
Service cost	23	19	18
Interest cost	33	39	43
Participant contributions	9	8
Actuarial (gain) loss	(80)	91
Benefits paid	(60)	(63)
Net benefit obligation at end of year	1,129	1,204	1,110
Change in plan assets:
Fair value of plan assets at beginning of year	1,453	1,297
Actual return on plan assets	154	209
Employer contributions	2	2	3
Participant contributions	9	8
Benefits paid	(60)	(63)
Fair value of plan assets at end of year	1,558	1,453	$ 1,297
Funded status – surplus	(429)	(249)
Accrued benefit asset at December 31	(429)	(249)
Amounts recognized in the balance sheet consist of:
Noncurrent asset	(429)	(249)
Liability, Defined Benefit Plan, Current	0	0
Liability, Defined Benefit Plan, Noncurrent	0	0
Amounts recognized in regulatory assets consist of:
Net actuarial gain	(343)	(200)
Prior service credit	(33)	(37)
Amounts recognized in accumulated OCI (pretax) consist of:
Net actuarial (gain) loss	1	6
Total	$ (375)	$ (231)