PENSION AND OTHER POSTRETIREMENT BENEFIT PROGRAMS - Net Periodic Benefit Cost Relating to Pension and Other Postemployment Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Pension benefits
Net periodic benefit cost
Service cost	$ 3	$ 3
Interest cost	31	34
Expected return on plan assets	(42)	(44)
Amortization of net losses and prior service costs	3	1
Net periodic pension cost (income)	(5)	(6)
OPEB
Net periodic benefit cost
Interest cost	1	2
Amortization of net losses and prior service costs	0	(4)
Net periodic pension cost (income)	$ 1	$ (2)