LONG-TERM DEBT (Details) (USD $)	3 Months Ended		9 Months Ended						3 Months Ended		9 Months Ended		12 Months Ended				9 Months Ended					9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011	Jul. 11, 2012	Dec. 31, 2011		Sep. 30, 2012 Revolving Credit Facility [Member]		Sep. 30, 2012 Revolving Credit Facility [Member]		Sep. 30, 2012 Revolving Credit Facility [Member]		Dec. 31, 2011 Revolving Credit Facility [Member]		Sep. 30, 2012 Revolving Credit Facility [Member] Minimum [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] Maximum [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] LIBOR [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] LIBOR [Member] Minimum [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] LIBOR [Member] Maximum [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] Prime rate [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] Prime rate [Member] Minimum [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] Prime rate [Member] Maximum [Member]	Jul. 11, 2012 Wells Fargo Bank, National Association [Member] Term Loan [Member]	Jul. 11, 2012 Wells Fargo Bank, National Association [Member] Revolving Credit Facility [Member]	Dec. 31, 2011 Wells Fargo Bank, National Association [Member] Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 325,000,000																			$ 100,000,000	$ 225,000,000	$ 200,000,000
Base rate																			LIBOR			prime
Basis spread on base rate (in hundredths)																			1.75%	1.25%	2.25%	0.75%	0.25%	1.25%
Incremental basis points for term loan (in hundredths)									0.25%		0.25%		0.25%
Commitment fee (in hundredths)											0.30%						0.20%	0.40%
Incremental higher interest rate after acquisition (in hundredths)											0.70%
Debt issuance costs expensed									700,000
Amount outstanding																			240,400,000			12,800,000
Weighted average interest rate																			2.09%			3.75%
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
Leverage Ratio									2.12		2.12		2.12
Minimum consolidated fixed charge coverage ratio											1.25
Fixed charge coverage ratio									3.65		3.65		3.65
Minimum asset coverage ratio											1.0
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%
Asset coverage ratio									1.43		1.43		1.43
Computation of the Leverage Ratio [Abstract]
Income before taxes	22,248,000	13,680,000	61,421,000		36,844,000								76,572,000
Interest expense	(2,287,000)	(760,000)	(3,878,000)		(2,805,000)								4,591,000
Depreciation and amortization													15,670,000
Stock compensation expense													1,818,000
Pro forma acquisition EBITDA													23,869,000
Other adjustments													(218,000)
(A) Defined EBITDA													122,302,000
Total long-term debt	259,031,000		259,031,000				114,899,000	[1]	259,031,000		259,031,000		259,031,000
Letters of credit outstanding									460,000		460,000		460,000
(B) Defined indebtedness									259,491,000		259,491,000		259,491,000
Leverage Ratio (B)/(A)									2.12		2.12		2.12
Borrowings [Abstract]
Current portion of long-term debt	18,098,000		18,098,000				694,000	[1]
Long-term debt, less current portion	240,933,000		240,933,000				114,205,000	[1]
Total long-term debt	259,031,000		259,031,000				114,899,000	[1]	259,031,000		259,031,000		259,031,000
Amount available									67,376,000	[2]	67,376,000	[2]	67,376,000	[2]	78,201,000	[1],[2]
Increase (decrease) in current portion of long-term debt			17,404,000
Increase (decrease) in long-term debt, less current maturities			126,728,000
Increase (decrease) in total long-term debt			144,132,000	[3]
Increase (decrease) in amount available											$ (10,825,000)	[4]

[1] Borrowings as of December 31, 2011 were primarily under the Company's previous credit facility which was terminated and replaced with the current credit facility on July 11, 2012.

[2] Represents amount available to be borrowed at the indicated date under the Facility.

[3] The funds obtained from the increase in debt were primarily used to fund acquisitions.

[4] The $10.8 million decrease in the amount available is primarily a result of borrowing to fund acquisitions, partially offset by cash flow from operations.