EMPLOYEE BENEFIT PLANS - Net Periodic Pension Cost (Credit) (Details) - Defined Benefit Pension Plan - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 21	$ 12	$ 50
Interest cost	610	742	1,786	1,810
Expected return on plan assets	(780)	(759)	(2,279)	(1,852)
Amortization of net actuarial loss	19	0	53	0
Net periodic pension cost (credit)	$ (147)	$ 4	$ (428)	$ 8