EMPLOYEE BENEFIT PLANS - ASSUMPTIONS (Details) - Qualified Defined Benefit [Member]	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Weighted-average discount rate			4.20%
Net period benefit costs, Weighted-average expected return on assets			6.50%
Minimum [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Weighted-average discount rate	3.69%	4.29%	4.55%
Benefit obligations, Rate of compensation increase	2.11%	2.12%	2.06%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Weighted-average discount rate	4.29%	4.55%
Net period benefit costs, Weighted-average expected return on assets	5.50%	6.00%
Net period benefit costs, Rate of compensation increase	2.12%	2.06%	2.85%
Maximum [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Weighted-average discount rate	3.78%	4.50%	4.69%
Benefit obligations, Rate of compensation increase	3.00%	2.59%	2.65%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Weighted-average discount rate	4.50%	4.69%
Net period benefit costs, Weighted-average expected return on assets	6.00%	6.50%
Net period benefit costs, Rate of compensation increase	2.59%	2.65%	3.91%