v3.25.4
Pension And Postretirement Benefits (Fair Value Assets Measured On Recurring Basis Unobservable Input (Level 3) Reconciliation) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Pension Assets1    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year $ 27,919 $ 30,098
Fair value of plan assets at end of year 28,677 27,919
Pension Assets1 | Level 3    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year 2,314 2,957
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold (315) 159
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held 325 (510)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) For Assets Transferred Into Level 3 319  
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase for Purchase 115 291
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Decrease for Sale (339) (583)
Fair value of plan assets at end of year 2,419 2,314
Pension Assets1 | Equity securities | Level 3    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year 2 2
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold 0 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held 0 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) For Assets Transferred Into Level 3 0  
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase for Purchase 0 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Decrease for Sale 0 0
Fair value of plan assets at end of year 2 2
Pension Assets1 | Fixed Income Funds [Member] | Level 3    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year 1 1
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold 0 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held 0 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) For Assets Transferred Into Level 3 0  
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase for Purchase 13 0
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Decrease for Sale 0 0
Fair value of plan assets at end of year 14 1
Pension Assets1 | Employee Benefit Plan, Real Estate [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year 2,311  
Fair value of plan assets at end of year 2,403 2,311
Pension Assets1 | Employee Benefit Plan, Real Estate [Member] | Level 3    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year 2,311 2,954
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold (315) 159
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held 325 (510)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) For Assets Transferred Into Level 3 319  
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase for Purchase 102 291
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Decrease for Sale (339) (583)
Fair value of plan assets at end of year 2,403 2,311
Other Postretirement Benefits Plan [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year 1,144 1,763
Fair value of plan assets at end of year 722 1,144
Other Postretirement Benefits Plan [Member] | Level 3    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year $ 0 $ 0