GOODWILL AND INTANGIBLE ASSETS (Details 5) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Goodwill [Line Items]
Goodwill impairment	$ 34,892,000
Engineered Support Structures
Goodwill [Line Items]
Goodwill impairment	18,670,000
Coatings
Goodwill [Line Items]
Goodwill impairment	0	$ 16,222,000
Utility Support Structures Segment
Goodwill [Line Items]
Goodwill impairment	$ 0	19,000,000
Webforge
Goodwill [Line Items]
Impairment of intangible assets		5,830
Industrial Galvanizers
Goodwill [Line Items]
Impairment of intangible assets		$ 1,100