RETIREMENT AND OTHER BENEFIT PROGRAMS - Fair Value of Pension Plan Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 2,973	$ 4,774
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	705	1,063
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,548	2,602
Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	10	10	$ 18
Fair value of pension plan assets	10	10
Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	710	1,099
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	224	145
Cash and Cash Equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	72	21
Cash and Cash Equivalents | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	152	124
Cash and Cash Equivalents | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Cash and Cash Equivalents | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
U.S Government and Government Agency Issues
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	452	735
U.S Government and Government Agency Issues | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U.S Government and Government Agency Issues | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	452	735
U.S Government and Government Agency Issues | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
U.S Government and Government Agency Issues | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Corporate Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	352	1,127
Corporate Debt Securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Corporate Debt Securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	352	1,127
Corporate Debt Securities | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Corporate Debt Securities | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Large Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	231	541
Common Stock Large Cap | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	231	541
Common Stock Large Cap | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Large Cap | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Large Cap | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Mid Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	158	298
Common Stock Mid Cap | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	158	298
Common Stock Mid Cap | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Mid Cap | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Mid Cap | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Small Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	37	91
Common Stock Small Cap | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	37	91
Common Stock Small Cap | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Small Cap | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock Small Cap | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	426	930
Common Stock | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	426	930
Common Stock | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common Stock | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	442	356
Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	189	135
Mutual Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	253	221
Mutual Funds | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Mutual Funds | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Common/Collective Trust Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	668	919
Common/Collective Trust Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	19	0
Common/Collective Trust Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	272	210
Common/Collective Trust Funds | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0	8
Common/Collective Trust Funds | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	377	709
Partnership Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	333	390
Partnership Investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Partnership Investments | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Partnership Investments | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Partnership Investments | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	333	390
Other Holdings
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	76	172
Other Holdings | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	8	11
Other Holdings | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	58	151
Other Holdings | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	10	10	$ 10
Other Holdings | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Collateral Held on Loaned Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	9	196
Collateral Held on Loaned Securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Collateral Held on Loaned Securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	9	196
Collateral Held on Loaned Securities | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Collateral Held on Loaned Securities | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Loaned Securities Pledged as Collateral
Defined Benefit Plan Disclosure [Line Items]
Collateral to be paid on loaned securities	(9)	(196)
Loaned Securities Pledged as Collateral | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Collateral to be paid on loaned securities	(9)	(34)
Loaned Securities Pledged as Collateral | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Collateral to be paid on loaned securities	0	(162)
Loaned Securities Pledged as Collateral | Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Collateral to be paid on loaned securities	0	0
Loaned Securities Pledged as Collateral | Fair Value, Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Collateral to be paid on loaned securities	$ 0	$ 0