EMPLOYEE BENEFIT PLANS - Net Periodic Pension Cost (Credit) (Details) - Defined Benefit Pension Plan - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 23	$ 0	$ 47
Interest cost	586	588	1,179	1,189
Expected return on plan assets	(600)	(948)	(1,207)	(1,918)
Amortization of unrecognized prior service cost	8	0	16	0
Net periodic pension credit	$ (6)	$ (337)	$ (12)	$ (682)