PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Accumulated and Projected Benefit Obligations in Excess of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	$ 3,762	$ 4,120
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets	3,005	3,307
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Asses, Projected Benefit Obligation	3,786	4,150
Defied Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets	3,005	3,307
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	$ 3,800	$ 4,100