PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Target Allocation and Actual Asset Allocations for Pension and VEBA Plan Assets) (Details)	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	100.00%	100.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Pension Benefits [Member] | Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	38.90%	43.60%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	45.00%
Pension Benefits [Member] | Fixed Income Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	26.00%	27.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	28.00%
Pension Benefits [Member] | Hedge Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	5.40%	5.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	5.00%
Pension Benefits [Member] | Private Equity Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	6.20%	5.30%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	7.00%
Pension Benefits [Member] | Structured Finance [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	11.40%	9.70%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	7.50%
Pension Benefits [Member] | Real Estate [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	10.30%	8.70%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	7.50%
Pension Benefits [Member] | Cash [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	1.80%	0.70%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Other Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	100.00%	100.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Other Benefits [Member] | Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	8.10%	8.70%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	8.00%
Other Benefits [Member] | Fixed Income Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	77.00%	77.70%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	80.00%
Other Benefits [Member] | Hedge Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	4.70%	4.40%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	4.00%
Other Benefits [Member] | Private Equity Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	1.20%	1.50%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	3.00%
Other Benefits [Member] | Structured Finance [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	3.50%	3.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	2.00%
Other Benefits [Member] | Real Estate [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	5.40%	4.60%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	3.00%
Other Benefits [Member] | Cash [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average asset allocation	0.10%	0.10%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%