EMPLOYEE BENEFIT PLANS (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) pension_plan	Jun. 30, 2017 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Number of qualified defined benefit plans | pension_plan			1
Weighted-average expected long-term rate of return on plan assets			7.20%
Pension
Defined Benefit Plan Disclosure [Line Items]
Pension contributions paid			$ 1,200
Minimum annual pension contribution	$ 2,900		2,900
Service cost	0	$ 0	0	$ 0
Interest cost	759	815	1,510	1,630
Expected return on plan assets	(984)	(945)	(1,968)	(1,891)
Amortization of losses	178	116	338	233
Net periodic benefit (credit) cost	(47)	(14)	(120)	(28)
Postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	3	3
Interest cost	13	13	25	26
Expected return on plan assets	0	0	0	0
Amortization of losses	0	0	1	0
Net periodic benefit (credit) cost	$ 15	$ 15	$ 29	$ 29