LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS (Details) (USD $) In Thousands, unless otherwise specified				12 Months Ended				12 Months Ended			12 Months Ended		0 Months Ended	12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Missouri IRBs [Member]	Dec. 31, 2012 Missouri IRBs [Member] Minimum [Member]	Dec. 31, 2012 Missouri IRBs [Member] Maximum [Member]	Dec. 31, 2012 Term Loan Under Credit Agreement, Variable [Member]	Dec. 31, 2011 Term Loan Under Credit Agreement, Variable [Member]	Dec. 31, 2012 Revolver Under Credit Agreement, Variable [Member]	Dec. 31, 2011 Revolver Under Credit Agreement, Variable [Member]	Dec. 31, 2012 Capital Leases [Member]	Dec. 31, 2012 Capital Leases [Member] Minimum [Member]	Dec. 31, 2012 Capital Leases [Member] Maximum [Member]	Aug. 07, 2012 Notes Payable [Member]	Dec. 31, 2012 Notes Payable [Member]	Dec. 31, 2011 Notes Payable [Member]	Dec. 31, 2012 Notes Payable [Member] Minimum [Member]	Dec. 31, 2011 Notes Payable [Member] Minimum [Member]	Dec. 31, 2012 Notes Payable [Member] Maximum [Member]	Dec. 31, 2011 Notes Payable [Member] Maximum [Member]	Dec. 31, 2012 Notes Payable to Prior Minority Shareholder [Member]
Debt Instrument [Line Items]
Long-term debt, gross			$ 8,113			$ 225,000	$ 0	$ 6,236	$ 0	$ 15,316			$ 1,000	$ 6,034	$ 29
Long-term debt, total	260,699	29
Less current installments	5,632	29
Total long-term debt and capital lease obligations	255,067	0
Fixed interest rate, minimum (in hundredths)				2.80%							3.00%					2.45%	6.48%
Fixed interest rate, maximum (in hundredths)					7.73%							7.73%		3.25%				2.56%	6.70%
Fixed interest rate (in hundredths)			2.80%										3.25%
Monthly installment payment																				$ 2,000
Maturity dates				Sep. 30, 2020	Jun. 30, 2032	Dec. 28, 2018		Dec. 28, 2017					Aug. 31, 2013
Number of monthly installments																				36