EMPLOYEE BENEFIT PLANS - ASSUMPTIONS (Details) - Qualified Defined Benefit [Member]	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Minimum [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Weighted-average discount rate	3.33%	4.37%	3.69%
Benefit obligations, Rate of compensation increase	2.11%	2.11%	2.11%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Weighted-average discount rate	4.37%	3.69%	4.29%
Net period benefit costs, Weighted-average expected return on assets	4.25%	4.25%	5.50%
Net period benefit costs, Rate of compensation increase	2.11%	2.11%	2.12%
Maximum [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Weighted-average discount rate	3.47%	4.46%	3.78%
Benefit obligations, Rate of compensation increase	5.44%	3.50%	16.51%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Weighted-average discount rate	4.46%	3.78%	4.50%
Net period benefit costs, Weighted-average expected return on assets	5.50%	5.50%	6.00%
Net period benefit costs, Rate of compensation increase	3.50%	16.51%	2.59%