v3.26.3
PENSIONS AND OTHER POSTRETIREMENT BENEFITS - Pension and Other Postretirement Benefits (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Net periodic benefit costs (credits) $ (64) $ (57) $ (192) $ (157)
Pension Plan        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service cost 7 7 21 21
Interest cost 45 53 135 158
Expected return on plan assets (81) (79) (244) (238)
Prior service credits 4 4 13 13
Net actuarial loss (gain) (4) (2) (13) (6)
Net periodic benefit costs (credits) (29) (17) (88) (52)
Defined benefit pension contributions 11 22 27 51
Defined benefit plan        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service cost 2 2 5 6
Interest cost 14 14 43 43
Expected return on plan assets (11) (11) (33) (32)
Termination benefits 0 0 0 15
Prior service credits (3) (3) (9) (10)
Net actuarial loss (gain) (28) (33) (84) (100)
Net periodic benefit costs (credits) (26) (31) (78) (78)
OPEB contributions $ 0 $ 0 $ 0 $ 0