EMPLOYEE BENEFIT PLANS - PLAN ASSETS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Qualified Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 1,858	$ 2,083	$ 1,846
Plan asset allocations	100.00%	100.00%
Qualified Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 1,749	$ 1,973
Qualified Defined Benefit [Member] | Equity funds [Member] | U.S.
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	28.00%	29.00%
Qualified Defined Benefit [Member] | Equity funds [Member] | U.S. | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 431	$ 515
Qualified Defined Benefit [Member] | Equity funds [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	12.00%	12.00%
Qualified Defined Benefit [Member] | Equity funds [Member] | Non-US [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 183	$ 226
Qualified Defined Benefit [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	53.00%	52.00%
Qualified Defined Benefit [Member] | Credit bond index fund [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 1,135	$ 1,232
Qualified Defined Benefit [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	7.00%	6.00%
Qualified Defined Benefit [Member] | Real Estate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 104	$ 97
Qualified Defined Benefit [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	0.00%	1.00%
Qualified Defined Benefit [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 5	$ 13
Qualified Defined Benefit Plan - Salaried [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	100.00%	100.00%
Qualified Defined Benefit Plan - Salaried [Member] | Equity funds [Member] | U.S.
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	6.00%	8.00%
Qualified Defined Benefit Plan - Salaried [Member] | Equity funds [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	3.00%	3.00%
Qualified Defined Benefit Plan - Salaried [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	91.00%	89.00%
Qualified Defined Benefit Plan - Salaried [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	0.00%	0.00%
Qualified Defined Benefit Plan - Salaried [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	0.00%	0.00%
Minimum [Member] | Qualified Defined Benefit [Member] | Equity funds [Member] | U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.25
Minimum [Member] | Qualified Defined Benefit [Member] | Equity funds [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.1
Minimum [Member] | Qualified Defined Benefit [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.48
Minimum [Member] | Qualified Defined Benefit [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.02
Minimum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Equity funds [Member] | U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.05
Minimum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Equity funds [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.01
Minimum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.86
Minimum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0
Maximum [Member] | Qualified Defined Benefit [Member] | Equity funds [Member] | U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.33
Maximum [Member] | Qualified Defined Benefit [Member] | Equity funds [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.16
Maximum [Member] | Qualified Defined Benefit [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.94
Maximum [Member] | Qualified Defined Benefit [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.08
Maximum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Equity funds [Member] | U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.09
Maximum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Equity funds [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.05
Maximum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.94
Maximum [Member] | Qualified Defined Benefit Plan - Salaried [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0