EARNINGS PER SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Basic EPS
Net earnings attributable to Valmont Industries, Inc, basic	$ 63,976	$ 89,563	$ 119,956	$ 167,132
Shares outstanding, basic	26,623	26,648	26,669	26,615
Per share amount, basic (in dollars per share)	$ 2.40	$ 3.36	$ 4.50	$ 6.28
Dilutive Effect of Stock Options
Dilutive effect of stock options number of shares	233	262	234	269
Dilutive effect of stock options (in dollars per share)	$ (0.02)	$ (0.03)	$ (0.04)	$ (0.06)
Diluted EPS
Net earnings attributable to Valmont Industries, Inc, diluted	$ 63,976	$ 89,563	$ 119,956	$ 167,132
Shares outstanding dilutive	26,856	26,910	26,903	26,884
Per share amount, diluted (in dollars per share)	$ 2.38	$ 3.33	$ 4.46	$ 6.22