EMPLOYEE BENEFIT PLANS - Net Periodic Pension Cost (Credit) (Details) - Foreign Pension Plan - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 22	$ 8	$ 29
Interest cost	597	801	1,176	1,068
Expected return on plan assets	(761)	(820)	(1,499)	(1,093)
Amortization of net actuarial loss	17	0	34	0
Net periodic pension cost (credit)	$ (143)	$ 3	$ (281)	$ 4