v3.25.4
Retirement Benefits (Schedule of Allocation of Plan Assets) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
DB Pension Plans      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets $ 3,177 $ 2,964 $ 3,004
DB Pension Plans | Plan Assets Excluding Pooled Funds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 162 148  
DB Pension Plans | Plan Assets Excluding Pooled Funds | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 162 148  
DB Pension Plans | Plan Assets Excluding Pooled Funds | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
DB Pension Plans | Cash and short-term investments      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 162 148  
DB Pension Plans | Cash and short-term investments | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 162 148  
DB Pension Plans | Cash and short-term investments | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
DB Pension Plans | Mutual funds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
DB Pension Plans | Mutual funds | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
DB Pension Plans | Mutual funds | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
DB Pension Plans | Pooled funds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 3,015 2,816  
OPEB Plan      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 1,733 1,588 $ 1,559
OPEB Plan | Plan Assets Excluding Pooled Funds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 466 356  
OPEB Plan | Plan Assets Excluding Pooled Funds | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 362 258  
OPEB Plan | Plan Assets Excluding Pooled Funds | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 104 98  
OPEB Plan | Cash and short-term investments      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 72 35  
OPEB Plan | Cash and short-term investments | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 72 35  
OPEB Plan | Cash and short-term investments | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
OPEB Plan | U.S. government and agencies securities      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 15 13  
OPEB Plan | U.S. government and agencies securities | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
OPEB Plan | U.S. government and agencies securities | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 15 13  
OPEB Plan | Corporate debt      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 69 68  
OPEB Plan | Corporate debt | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
OPEB Plan | Corporate debt | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 69 68  
OPEB Plan | State and municipal bonds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 4 2  
OPEB Plan | State and municipal bonds | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
OPEB Plan | State and municipal bonds | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 4 2  
OPEB Plan | Foreign bonds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 16 15  
OPEB Plan | Foreign bonds | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
OPEB Plan | Foreign bonds | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 16 15  
OPEB Plan | Common stocks      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 215 170  
OPEB Plan | Common stocks | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 215 170  
OPEB Plan | Common stocks | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
OPEB Plan | Mutual funds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 75 53  
OPEB Plan | Mutual funds | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 75 53  
OPEB Plan | Mutual funds | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets 0 0  
OPEB Plan | Pooled funds      
Defined Benefit Plan Disclosure [Line Items]      
Plan assets $ 1,267 $ 1,232