Employee Benefit Plans (Schedule Of Fair Value Of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,742	$ 2,337
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	135	251
Equity Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	135	251
Mutual Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	426	666
Mutual Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	426	666
Common collective trust funds - International equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	193	316
Common collective trust funds - U.S. equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	34	23
Debt instruments - Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	304	328
Debt instruments - Corporate bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	304	328
Debt instruments - U.S. Treasury instruments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	226	345
Debt instruments - U.S. Treasury instruments [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	226	345
Debt instruments - U.S. government agency, state and local government bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	4
Debt instruments - U.S. government agency, state and local government bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	4
Other Debt Instruments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	9
Other Debt Instruments [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	9
Common Collective Trust - Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	285	245
Common Collective Trust - Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	128	150
Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,102	1,603
Fair Value, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	787	1,262
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 315	$ 341