EMPLOYEE BENEFIT PLANS- Net periodic benefit cost (credit) and related components (Details) (Multiple employer pension plan, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Multiple employer pension plan
Multiemployer Plans [Line Items]
Interest cost	$ 58	$ 64	$ 117	$ 127
Expected return on plan assets	(92)	(83)	(184)	(165)
Amortization of net losses	17	16	34	31
Net periodic benefit	$ (17)	$ (3)	$ (33)	$ (7)