EMPLOYEE BENEFIT PLAN - Components of net periodic benefit cost (Details) - Multiple Employers Retirement Income Plan - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 411	$ 490
Expected return on plan assets	(395)	(650)
Amortization of net losses	246	230
Net periodic benefit cost	$ 262	$ 70