EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Basic EPS
Net earnings attributable to Valmont Industries, Inc, basic	$ 27,873	$ 63,976	$ 58,612	$ 119,956
Shares outstanding basic	23,336	26,623	23,602	26,669
Per share amount basic (in dollars per share)	$ 1.19	$ 2.40	$ 2.48	$ 4.50
Dilutive Effect of Stock Options
Dilutive effect of stock options number of shares	114	233	114	234
Dilutive effect of stock options (in dollars per share)		$ (0.02)	$ (0.01)	$ (0.04)
Diluted EPS
Net earnings attributable to Valmont Industries, Inc, diluted	$ 27,873	$ 63,976	$ 58,612	$ 119,956
Shares outstanding dilutive	23,450	26,856	23,716	26,903
Per share amount diluted (in dollars per share)	$ 1.19	$ 2.38	$ 2.47	$ 4.46
Antidilutive Securities
Outstanding stock options with exercise prices exceeding the market price of common stock, excluded from the computation of diluted earnings per share (in shares)			452,459