v3.26.3
PENSION AND OTHER POST-EMPLOYMENT BENEFIT OBLIGATIONS - Schedule of net benefit costs (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Pension        
Defined Benefit Plan Disclosure [Line Items]        
Current service cost $ (5) $ (4) $ (13) $ (13)
Interest cost (6) (6) (19) (17)
Expected return on plan assets 6 6 18 17
Immediate recognition of losses arising over the year 0 0 0 0
Amortization of past service gain 0 0 1 1
Amortization of net actuarial gain 1 0 1 0
Curtailment and settlements (1) 0 (1) 0
Total net pension and other long-term benefit cost (5) (4) (13) (12)
OPEB and Other Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Current service cost (1) (1) (4) (3)
Interest cost (2) (1) (5) (5)
Expected return on plan assets 0 0 0 0
Immediate recognition of losses arising over the year 0 0 (4) 0
Amortization of past service gain 3 3 8 8
Amortization of net actuarial gain 0 0 1 1
Curtailment and settlements 0 0 0 0
Total net pension and other long-term benefit cost $ 0 $ 1 $ (4) $ 1