PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net effect of remeasurement reduction in funded status				$ 24
Defined Benefit Plan, Plan Assets, Period Increase (Decrease)	$ 16
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)	6
Defined Benefit Plan Funded Status Period Increase (Decrease)						$ 22
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 40			$ 40
Maximum
Defined Benefit Plan Disclosure [Line Items]
Increase in fair value of pension assets, percentage	1.00%			1.00%
Increase/decrease in pension projected benefit obligation, percentage	1.00%			1.00%
U.S. Qualified Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan						$ 1,500
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate				4.30%		4.40%
Pension
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Payment for Settlement	$ 449	$ 455
Reduction in settlement charge	$ 6		$ 0	$ (449)	$ 0