BUSINESS ACQUISITIONS (Details) - USD ($) $ in Thousands			3 Months Ended	12 Months Ended
	Sep. 01, 2015	Apr. 01, 2015	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2015	Apr. 02, 2015
Business Acquisition [Line Items]
Goodwill acquired				$ 187,591	$ 187,591	$ 197,362
Goodwill adjustment				(151)
Business Acquired during 2015 [Member]
Business Acquisition [Line Items]
Sales from business acquisitions				25,200
Earnings (loss) before taxes and impairment from business acquisitions				$ (300)
Tool Supply, Inc. [Member]
Business Acquisition [Line Items]
Purchase price		$ 5,000
Intangible assets acquired							$ 2,000
Goodwill acquired							$ 2,900
Cortech Engineering, LLC [Member]
Business Acquisition [Line Items]
Purchase price	$ 14,900
Purchase price financed under common stock issued	$ 4,400
Number of shares issued on acquisition (in shares)	148,800
Intangible assets acquired	$ 5,200
Goodwill acquired			$ 8,700
Goodwill adjustment			$ 151
Nontax deductible goodwill or intangible assets	$ 4,500