LONG-TERM DEBT (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jul. 11, 2012
Borrowings [Abstract]
Long-term debt	$ 238,396,000	$ 114,899,000
Current portion of long-term debt	(22,057,000)	(694,000)
Total long-term debt	216,339,000	114,205,000
Maximum borrowing capacity				325,000,000
Leverage Ratio	1.87
Computation of the Leverage Ratio [Abstract]
Income before taxes	85,009,000	51,995,000	32,132,000
Interest expense	5,560,000	3,518,000	5,208,000
Depreciation and amortization	18,082,000
Stock compensation expense	1,955,000
Pro forma acquisition EBITDA	16,542,000
Other adjustments	913,000
Defined EBITDA	128,061,000
Letters of credit outstanding	476,000
Defined indebtedness	238,872,000
Leverage Ratio (B)/(A)	1.87
Long-term Debt, Fiscal Year Maturity [Abstract]
2013	22,057,000
2014	25,495,000
2015	31,943,000
2016	34,376,000
2017	124,525,000
Thereafter	0
Line of Credit [Member]
Borrowings [Abstract]
Long-term debt	104,526,000	110,828,000
Term Loan [Member]
Borrowings [Abstract]
Long-term debt	130,000,000	0
Term Loan [Member] | Prime rate [Member]
Borrowings [Abstract]
Basis spread on base rate (in hundredths)	0.02%
Unsecured Notes Payable to Individual [Member]
Borrowings [Abstract]
Long-term debt	3,870,000	2,320,000
Mortgage loan payable [Member]
Borrowings [Abstract]
Long-term debt	0	1,751,000
Revolving Credit Facility [Member]
Borrowings [Abstract]
Increase in borrowing capacity	75,000,000
Incremental basis points for term loan (in hundredths)	0.25%
Commitment fee (in hundredths)	0.30%
Incremental higher interest rate after acquisition (in hundredths)	0.70%
Debt issuance costs expensed	700,000
Available for borrowing under the facility	109,500,000
Expiration date	Jul. 11, 2017
Maximum consolidated leverage ratio required through March 31, 2015	3.5
Maximum consolidated leverage ratio required from June 30, 2015 and thereafter	3.25
Minimum asset coverage ratio	1.0
Leverage Ratio	1.87
Minimum consolidated fixed charge coverage ratio	1.25
Fixed charge coverage ratio	3.10
Asset coverage ratio	2.04
Percentage of net accounts receivable for calculating asset coverage ratio (in hundredths)	85.00%
Percentage of net inventory for calculating asset coverage ratio (in hundredths)	65.00%
Computation of the Leverage Ratio [Abstract]
Leverage Ratio (B)/(A)	1.87
Revolving Credit Facility [Member] | Minimum [Member]
Borrowings [Abstract]
Commitment fee (in hundredths)	0.20%
Revolving Credit Facility [Member] | Maximum [Member]
Borrowings [Abstract]
Commitment fee (in hundredths)	0.40%
Revolving Credit Facility [Member] | LIBOR [Member]
Borrowings [Abstract]
Base rate	LIBOR
Basis spread on base rate (in hundredths)	1.75%
Amount outstanding	226,500,000
Weighted average interest rate (in hundredths)	2.11%
Revolving Credit Facility [Member] | LIBOR [Member] | Minimum [Member]
Borrowings [Abstract]
Basis spread on base rate (in hundredths)	1.25%
Revolving Credit Facility [Member] | LIBOR [Member] | Maximum [Member]
Borrowings [Abstract]
Basis spread on base rate (in hundredths)	2.25%
Revolving Credit Facility [Member] | Prime rate [Member]
Borrowings [Abstract]
Base rate	prime
Basis spread on base rate (in hundredths)	0.75%
Amount outstanding	8,000,000
Weighted average interest rate (in hundredths)	3.75%
Revolving Credit Facility [Member] | Prime rate [Member] | Minimum [Member]
Borrowings [Abstract]
Basis spread on base rate (in hundredths)	0.25%
Revolving Credit Facility [Member] | Prime rate [Member] | Maximum [Member]
Borrowings [Abstract]
Basis spread on base rate (in hundredths)	1.25%
Wells Fargo Bank, National Association [Member] | Line of Credit [Member]
Borrowings [Abstract]
Maximum borrowing capacity				262,500,000
Wells Fargo Bank, National Association [Member] | Term Loan [Member]
Borrowings [Abstract]
Maximum borrowing capacity				$ 130,000,000