COMMITMENTS AND CONTINGENCIES (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2001
Finance Obligation [Abstract]
Year Ending December 31, 2013	$ 1,516,000
Year Ending December 31, 2014	1,516,000
Year Ending December 31, 2015	1,516,000
Year Ending December 31, 2016	1,516,000
Year Ending December 31, 2017	0
Thereafter	0
Finance Obligation, Total	6,064,000
Less amount representing interest	(6,064,000)
Finance obligation net of interest	0
Operating Leases [Abstract]
Year Ending December 31, 2013	22,546,000
Year Ending December 31, 2014	21,270,000
Year Ending December 31, 2015	19,594,000
Year Ending December 31, 2016	15,819,000
Year Ending December 31, 2017	14,626,000
Thereafter	48,456,000
Operating Leases, Total	142,311,000
Less amount representing interest	0
Operating leases net of interest	142,311,000
Capital Leases [Abstract]
Year Ending December 31, 2013	2,506,000
Year Ending December 31, 2014	2,494,000
Year Ending December 31, 2015	2,494,000
Year Ending December 31, 2016	2,556,000
Year Ending December 31, 2017	2,678,000
Thereafter	39,815,000
Capital Leases, Total	52,543,000
Less amount representing interest	(26,188,000)
Capital leases net of interest	26,355,000
Number of owned facilities	4
Net proceeds from sale and leaseback transaction	8,800,000
Lease Term	15 years
Period considered for lease extension	10 years
Lease rent expense	23,400,000	23,500,000	23,500,000	1,200,000
Interest expense related to financing obligations	1,500,000	1,500,000	1,400,000
Outstanding net loan commitment	25,000,000
Future employment contract commitments	8,900,000
Surety bonds	$ 14,900,000