PENSION PLAN - Weighted Average Assumptions and Net Periodic Pension Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	May 31, 2014
Weighted average assumptions used to determine the benefit obligation
Discount rate	3.55%	4.05%	4.30%	4.46%
Components of net periodic pension cost
Service cost	$ 0	$ 0	$ 0
Interest cost	360	367	315
Expected return on plan assets	(345)	(330)	(316)
Amortization of prior service costs	0	0	0
Amortization of net actuarial loss	241	236	257
Net periodic pension cost	$ 256	$ 273	$ 256
Weighted average assumptions used to determine net periodic pension cost
Discount rate	4.05%	4.30%	3.90%
Expected long-term rate of return on plan assets	6.75%	6.75%	6.75%