ACCRUED LIABILITIES (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
ACCRUED LIABILITIES
Wages and employee benefits	$ 10,450	$ 9,028
Insurance accruals	9,700	9,711
Accrued taxes	381	380
Accrued professional fees and other	1,343	2,348
Total accrued liabilities	$ 21,874	$ 21,467