EMPLOYEE BENEFIT PLANS - Schedule of Asset Allocations (Details)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Asset Allocations	100.00%	100.00%
Target Asset Allocations	100.00%	100.00%
Equity securities and diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Asset Allocations	26.90%	28.10%
Target Asset Allocations	27.50%	27.50%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Asset Allocations	56.70%	59.20%
Target Asset Allocations	72.50%	72.50%
Other
Defined Benefit Plan Disclosure [Line Items]
Asset Allocations	16.40%	12.70%
Target Asset Allocations	0.00%	0.00%
Minimum | Equity securities and diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocations	25.00%
Minimum | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocations	70.00%
Maximum | Equity securities and diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocations	30.00%
Maximum | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocations	75.00%