EMPLOYEE BENEFIT PLANS- Net periodic benefit cost (credit) and related components (Details) - Multiple employer pension plan - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Multiemployer Plans [Line Items]
Interest cost	$ 65	$ 65	$ 194	$ 195
Expected return on plan assets	(106)	(103)	(316)	(307)
Amortization of net losses	19	9	57	27
Net periodic benefit	$ (22)	$ (29)	$ (65)	$ (85)