EMPLOYEE BENEFIT PLANS - Assumptions (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate (as a percent)	3.47%	3.98%	4.17%
Weighted-average assumptions used to determine net periodic cost
Discount rate (as a percent)	3.98%	4.17%	3.83%
Expected long-term return on plan assets (as a percent)	7.00%	7.00%	7.00%