BUSINESS ACQUISITIONS (Details) (USD $)	3 Months Ended							0 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Minimum [Member]	Mar. 31, 2013 Maximum [Member]	Jan. 31, 2012 Mid Continent Safety [Member]	Feb. 29, 2012 Pump & Power Equipment, Inc. [Member]	Apr. 02, 2012 Aledco, Inc. [Member]	May 01, 2012 Industrial Paramedic Services [Member]	May 01, 2012 Industrial Paramedic Services [Member] Promissory Notes [Member]	Jul. 11, 2012 HSE Integrated Ltd. [Member]	May 31, 2012 Austin and Denholm Industrial Sales Alberta, Inc. [Member]	Oct. 01, 2012 Jerzy Supply, Inc. [Member]
Purchase price allocation [Abstract]
Cash	$ 12,374,000
Accounts Receivable, net	34,949,000
Inventory, net	4,051,000
Property and equipment	34,889,000
Goodwill and intangibles	75,489,000
Other assets	2,698,000
Assets acquired	164,450,000
Current liabilities assumed	(26,293,000)
Non current liabilities assumed	(15,296,000)
Net assets acquired	122,861,000
Business Acquisition [Line Items]
Purchase price					3,700,000	1,900,000	8,100,000	25,300,000		85,000,000	2,700,000	5,300,000
Borrowings under existing credit facility								20,600,000
Goodwill on acquisition					1,200,000	700,000	3,400,000	12,100,000		27,600,000	300,000	0
Number of shares issued on acquisition (in shares)								19,685
Number of operating locations								3
Borrowings under notes									2,500,000
Stated interest rate (in hundredths)									5.00%
Share price (in dollars per share)										$ 1.80
Liabilities assumed on acquisiton										4,000,000
Transaction cost										3,000,000
Discount rate for valuation of acquired intangibles (in hundredths)			17.00%	28.20%
Sales from business acquisitions	43,400,000
Earnings from business acquisitions	1,900,000
Pro Forma Information [Abstract]
Net sales	290,097,000	292,868,000
Net income	$ 13,232,000	$ 14,008,000
Per share data [Abstract]
Basic earnings (in dollars per share)	$ 0.92	$ 0.98
Diluted earnings (in dollars per share)	$ 0.87	$ 0.92