GOODWILL AND INTANGIBLE ASSETS (Details 2) - USD ($) $ in Thousands	Dec. 26, 2015	Dec. 27, 2014
Webforge
Non-amortized intangible assets
Carrying value of trade names	$ 10,430	$ 16,801
Valmont SM
Non-amortized intangible assets
Carrying value of trade names	8,919	10,818
Newmark
Non-amortized intangible assets
Carrying value of trade names	11,111	11,111
Ingal EPS/Ingal Civil Products
Non-amortized intangible assets
Carrying value of trade names	8,504	8,867
Donhad
Non-amortized intangible assets
Carrying value of trade names	6,415	6,689
Shakespeare
Non-amortized intangible assets
Carrying value of trade names	4,000	4,000
Industrial Galvanizers
Non-amortized intangible assets
Carrying value of trade names	2,662	3,889
Other
Non-amortized intangible assets
Carrying value of trade names	13,889	14,852
Trade Names
Non-amortized intangible assets
Carrying value of trade names	$ 65,930	$ 77,027