RETIREMENT BENEFITS - Fair Value of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	$ 1,927	$ 2,212
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	58	33
Level 1 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	1	1
Level 1 | Equity funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | U.S. Treasury and agency securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	57	32
Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	754	1,556
Level 2 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 2 | Equity funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	256	363
Level 2 | Fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	446	785
Level 2 | Corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	332
Level 2 | U.S. Treasury and agency securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	41	58
Level 2 | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset		0
Level 2 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	11	18
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	708	269
Level 3 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Equity funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	7
Level 3 | Fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | U.S. Treasury and agency securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	708	224
Level 3 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset		38
Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	1,520	1,858
Fair Value, Inputs, Level 1, 2 and 3 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	1	1
Fair Value, Inputs, Level 1, 2 and 3 | Equity funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	256	370
Fair Value, Inputs, Level 1, 2 and 3 | Fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	446	785
Fair Value, Inputs, Level 1, 2 and 3 | Corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	0	332
Fair Value, Inputs, Level 1, 2 and 3 | U.S. Treasury and agency securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	41	58
Fair Value, Inputs, Level 1, 2 and 3 | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	708	224
Fair Value, Inputs, Level 1, 2 and 3 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	57	32
Fair Value, Inputs, Level 1, 2 and 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	11	56
Plan assets measured at NAV as a practical expedient | Plan assets measured at NAV as a practical expedient
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension and postretirement plan asset	$ 407	$ 354