EMPLOYEE BENEFIT PLANS - Investment of Plan Assets (Details) - Pension Benefits	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of  Plan Assets	100.00%	100.00%
Domestic equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of  Plan Assets	44.00%	41.00%
International equity securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of  Plan Assets	30.00%	28.00%
Domestic fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of  Plan Assets	21.00%	25.00%
International fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of  Plan Assets	3.00%	4.00%
Real estate fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of  Plan Assets	2.00%	2.00%
Defined Benefit Plan, Equity Securities [Member] | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of  Plan Assets	80.00%