v3.25.4
POSTRETIREMENT BENEFIT PLANS - Composition of Plan Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Jan. 01, 2023
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets     $ 18,908
Pension Plans      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets     $ 18,908
Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 18,259 $ 17,654  
Level 1 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 4,258 2,258  
Level 2 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 5,484 8,091  
Level 3 | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,564 692  
Level 3 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,564 692  
Net Asset Value | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 5,825 6,612  
Global equity securities | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 4,832 4,084  
Global equity securities | Level 1 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,292 944  
Global equity securities | Level 2 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 108 38  
Global equity securities | Level 3 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Global equity securities | Net Asset Value | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,432 3,101  
Debt securities, cash, and cash equivalents | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 8,412 10,593  
Debt securities, cash, and cash equivalents | Level 1 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,042 1,307  
Debt securities, cash, and cash equivalents | Level 2 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 5,330 8,000  
Debt securities, cash, and cash equivalents | Level 3 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Debt securities, cash, and cash equivalents | Net Asset Value | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1,040 1,285  
Real estate | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 793 1,100  
Real estate | Level 1 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Real estate | Level 2 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0 0  
Real estate | Level 3 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 299 476  
Real estate | Net Asset Value | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 494 623  
Private equities and other investments | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1,990 1,877  
Private equities and other investments | Level 1 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets (75) 7  
Private equities and other investments | Level 2 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 46 53  
Private equities and other investments | Level 3 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 161 216  
Private equities and other investments | Net Asset Value | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1,858 $ 1,602  
Annuity contract | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,104    
Annuity contract | Level 1 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0    
Annuity contract | Level 2 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0    
Annuity contract | Level 3 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2,104    
Annuity contract | Net Asset Value | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0    
Other | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 128    
Other | Level 1 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0    
Other | Level 2 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0    
Other | Level 3 | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0    
Other | Net Asset Value | Pension Plans | Recurring      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 0