RETIREMENT BENEFITS - Fair Value of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	$ 2,212	$ 2,027
Level 1
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	33	44
Level 1 | Equity securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	1	1
Level 1 | Equity funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Fixed income funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Corporate debt securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | U.S. Treasury and agency securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Insurance contracts
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 1 | Cash and cash equivalents
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	32	43
Level 1 | Other
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 2
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	1,556	1,531
Level 2 | Equity securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 2 | Equity funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	363	368
Level 2 | Fixed income funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	785	697
Level 2 | Corporate debt securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	332	376
Level 2 | U.S. Treasury and agency securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	58	75
Level 2 | Insurance contracts
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 2 | Cash and cash equivalents
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 2 | Other
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	18	15
Level 3
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	269	158
Level 3 | Equity securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Equity funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	7	0
Level 3 | Fixed income funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Corporate debt securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | U.S. Treasury and agency securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Insurance contracts
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	224	123
Level 3 | Cash and cash equivalents
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	0	0
Level 3 | Other
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	38	35
Fair Value, Inputs, Level 1, 2 and 3
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	1,858	1,733
Fair Value, Inputs, Level 1, 2 and 3 | Equity securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	1	1
Fair Value, Inputs, Level 1, 2 and 3 | Equity funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	370	368
Fair Value, Inputs, Level 1, 2 and 3 | Fixed income funds
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	785	697
Fair Value, Inputs, Level 1, 2 and 3 | Corporate debt securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	332	376
Fair Value, Inputs, Level 1, 2 and 3 | U.S. Treasury and agency securities
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	58	75
Fair Value, Inputs, Level 1, 2 and 3 | Insurance contracts
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	224	123
Fair Value, Inputs, Level 1, 2 and 3 | Cash and cash equivalents
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	32	43
Fair Value, Inputs, Level 1, 2 and 3 | Other
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	56	50
Plan assets measured at NAV as a practical expedient | Plan assets measured at NAV as a practical expedient
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Fair value of pension and postretirement plan asset	$ 354	$ 294