EMPLOYEE BENEFIT PLAN (Details) (Multiple Employer Retirement Income Plan, USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Multiple Employer Retirement Income Plan
Multiemployer Plans [Line Item]
Service cost
Interest cost	468	479	1,402	1,437
Expected return on plan assets	(462)	(458)	(1,386)	(1,374)
Amortization of net losses	167	116	501	348
Net periodic benefit cost	$ 173	$ 137	$ 517	$ 411