Retirement Benefits (Schedule Of Allocation Of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
DB Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 2,820	$ 3,599	$ 3,402
DB Pension Plans | Plan Assets Excluding Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	385	1,698
DB Pension Plans | Plan Assets Excluding Pooled Funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	385	815
DB Pension Plans | Plan Assets Excluding Pooled Funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		883
DB Pension Plans | Cash and short-term investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets	122	30
DB Pension Plans | Cash and short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	122	30
DB Pension Plans | U.S. government and agencies securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	209
DB Pension Plans | U.S. government and agencies securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		209
DB Pension Plans | Corporate debt
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	595
DB Pension Plans | Corporate debt | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		595
DB Pension Plans | State and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	13
DB Pension Plans | State and municipal bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		13
DB Pension Plans | Foreign corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	66
DB Pension Plans | Foreign corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		66
DB Pension Plans | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	263	785
DB Pension Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	263	785
DB Pension Plans | Pooled funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2,435	1,901
OPEB Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1,446	1,787	$ 1,645
OPEB Plan | Plan Assets Excluding Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	851	1,155
OPEB Plan | Plan Assets Excluding Pooled Funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	851	1,047
OPEB Plan | Plan Assets Excluding Pooled Funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		108
OPEB Plan | Cash and short-term investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets	28	21
OPEB Plan | Cash and short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	28	21
OPEB Plan | U.S. government and agencies securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	25
OPEB Plan | U.S. government and agencies securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		25
OPEB Plan | Corporate debt
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	73
OPEB Plan | Corporate debt | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		73
OPEB Plan | State and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	2
OPEB Plan | State and municipal bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		2
OPEB Plan | Foreign corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	8
OPEB Plan | Foreign corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		8
OPEB Plan | Common stocks
Defined Benefit Plan Disclosure [Line Items]
Plan assets	69	85
OPEB Plan | Common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	69	85
OPEB Plan | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	754	941
OPEB Plan | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	754	941
OPEB Plan | Pooled funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 595	$ 632