BUSINESS ACQUISITIONS (Details) (USD $)	3 Months Ended						0 Months Ended	3 Months Ended								0 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Business acquired in 2013 [Member]	Mar. 31, 2014 Business acquired in 2014 [Member]	Mar. 31, 2014 Minimum [Member]	Mar. 31, 2014 Maximum [Member]	Apr. 16, 2013 National Process Equipment Inc. [Member]	Dec. 31, 2013 National Process Equipment Inc. [Member]	Mar. 31, 2014 National Process Equipment Inc. [Member]	Mar. 31, 2014 Tucker Tool Company, Inc. [Member]	May 17, 2013 Tucker Tool Company, Inc. [Member]	Mar. 31, 2014 Alaska Pump and Supply, Inc. [Member]	Jul. 02, 2013 Alaska Pump and Supply, Inc. [Member]	Mar. 31, 2014 Tool Tech Industrial Machine and Supply, Inc. [Member]	Jul. 31, 2013 Tool Tech Industrial Machine and Supply, Inc. [Member]	Jan. 02, 2014 B27, LLC [Member]	Mar. 31, 2014 B27, LLC [Member]
Purchase price allocation [Abstract]
Cash	$ 2,968,000								$ 0	$ 0		$ 0		$ 430,000			$ 2,538,000
Accounts Receivable, net	69,431,000								14,549,000	505,000		1,424,000		1,505,000			51,448,000
Inventory	15,305,000								6,883,000	209,000		1,332,000		409,000			6,472,000
Property and equipment	18,081,000								3,317,000	0		172,000		19,000			14,573,000
Goodwill and intangibles	330,534,000								39,345,000	4,678,000		12,148,000		7,254,000			267,109,000
Other assets	2,252,000								698,000	0		389,000		2,000			1,163,000
Assets acquired	438,571,000								64,792,000	5,392,000		15,465,000		9,619,000			343,303,000
Current liabilities assumed	49,701,000								19,175,000	391,000		1,079,000		1,987,000			27,069,000
Non-current liabilities assumed	29,750,000								5,649,000	0		1,419,000		0			22,682,000
Net assets acquired	359,120,000								39,968,000	5,001,000		12,967,000		7,632,000			293,552,000
Maximum period of information after acquisition date for revision in estimates	1 year
Purchase price							40,000,000				5,000,000		13,000,000		7,600,000	293,600,000
Borrowings under existing credit facility							36,600,000
Number of shares issued on acquisition (in shares)							52,542									36,000
Earnout amount							6,000,000
Fair value of earnout recorded at acquisition date							2,800,000
Earnout liability								0
Reduction in selling, general and administrative expense								2,800,000
Goodwill acquired							24,600,000				3,200,000		8,100,000		4,900,000	186,000,000
Intangible assets acquired							14,800,000				1,500,000		4,100,000		2,400,000	81,100,000
Purchase price financed under common stock issued																4,000,000
Transaction cost																1,000,000
Nontax deductible goodwill or intangible assets																213,700,000
Discount rate for valuation of acquired intangibles (in hundredths)					13.50%	15.90%
Sales from business acquisitions			23,000,000	30,400,000
Earnings (loss) before taxes from business acquisitions			(800,000)	(1,500,000)
Pro Forma Information [Abstract]
Net sales	348,504,000	351,537,000
Net income	$ 11,595,000	$ 13,796,000
Per share data [Abstract]
Basic earnings (in dollars per share)	$ 0.79	$ 0.95
Diluted earnings (in dollars per share)	$ 0.75	$ 0.90