SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Large-deductible workers' compensation insurance program | Maximum
Insurance Programs
Insurance program, Company's risk per incident	$ 400
Self-insured employee health program
Insurance Programs
Insurance program, Company's risk per individual covered life	100
D&O coverage | Minimum
Insurance Programs
Insurance program, Company's risk per claim	100
D&O coverage | Maximum
Insurance Programs
Insurance program, Company's risk per claim	$ 250