PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 1	$ (8)	$ (11)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	39	38	39
Defined Benefit Plan, Interest Cost	128	129	131
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	218	221	217
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(1)	(1)	(1)
Defined Benefit Plan, Amortization of Gain (Loss)	(95)	(83)	(75)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	43	28	27
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax	(31)	(131)	(208)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	(1)	(1)	(1)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	95	83	75
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	(63)	49	134
Total recognized in net periodic benefit cost and other comprehensive loss or income	(20)	77	161
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	1	1	1
Defined Benefit Plan, Interest Cost	6	8	8
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0
Defined Benefit Plan, Amortization of Gain (Loss)	9	6	7
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(2)	3	2
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax	2	23	(4)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	0	0	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	(9)	(6)	(7)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	7	(17)	11
Total recognized in net periodic benefit cost and other comprehensive loss or income	$ 5	$ (14)	$ 13