RETIREMENT BENEFITS PLANS - Fair Value of Other Postretirement Benefits Plan Assets (Details) - Other postretirement benefits plans - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Fair Value of Other Postretirement Benefits Plan Assets [Line Items]
Cash equivalents	$ 3	$ 2
Common collective and other trusts measured at net asset value	15	15
Total other postretirement benefits plan assets	18	17
Quoted prices in active markets for identical assets (Level 1)
Fair Value of Other Postretirement Benefits Plan Assets [Line Items]
Cash equivalents	3	2
Total other postretirement benefits plan assets	3	2
Other observable inputs (Level 2)
Fair Value of Other Postretirement Benefits Plan Assets [Line Items]
Cash equivalents	0	0
Total other postretirement benefits plan assets	0	0
Unobservable inputs (Level 3)
Fair Value of Other Postretirement Benefits Plan Assets [Line Items]
Cash equivalents	0	0
Total other postretirement benefits plan assets	$ 0	$ 0