ACCRUED LIABILITIES - (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Payables and Accruals [Abstract]
Accrued insurance reserves	$ 10,123	$ 9,816
Accrued materials	8,987	5,745
Accrued compensation and benefits	7,379	7,381
Accrued property, sales and other taxes	3,828	4,632
Accrued rent	2,416	1,904
Accrued interest	1,757	547
Other	4,925	6,405
Accrued Liabilities and Other Liabilities	$ 39,415	$ 36,430