Annual report [Section 13 and 15(d), not S-K Item 405]

PENSION AND POST RETIREMENT BENEFITS - Components of Accumulated Other Comprehensive Loss (Income) (Details)

v3.25.0.1
PENSION AND POST RETIREMENT BENEFITS - Components of Accumulated Other Comprehensive Loss (Income) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation $ (113) $ 42
Actual returns on assets under (over) expected 67 (60)
Amortization of net actuarial gain (loss) 1 (3)
Amortization of prior service credits (costs) (18) (18)
Settlements 2 4
Plan amendments 0 3
OPEB    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation 335 (12)
Actual returns on assets under (over) expected (3) (24)
Amortization of net actuarial gain (loss) 154 145
Amortization of prior service credits (costs) 15 17
Settlements 0 0
Plan amendments 7 8
Discount rates | Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation (146) 124
Discount rates | OPEB    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation (43) 28
Demographic updates | Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation (14) (5)
Demographic updates | OPEB    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation 26 (208)
Mortality | Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation 0 (2)
Mortality | OPEB    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation 0 (11)
Per capita healthcare costs | Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation 0 0
Per capita healthcare costs | OPEB    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation 179 33
Other | Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation (5) (1)
Other | OPEB    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation 0 0
Actuarial loss (gain) on benefit obligation | Pension Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation (165) 116
Actuarial loss (gain) on benefit obligation | OPEB    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial loss (gain) on benefit obligation $ 162 $ (158)