EARNINGS PER SHARE (Details) - USD ($)	3 Months Ended
	Mar. 26, 2016	Mar. 28, 2015
Basic EPS
Net earnings attributable to Valmont Industries, Inc.	$ 32,969,000	$ 30,739,000
Shares outstanding basic (in shares)	22,700,000	23,868,000
Per share amount basic (in dollars per share)	$ 1.45	$ 1.29
Dilutive Effect of Stock Options
Dilutive Effect of Stock Options	$ 0	$ 0
Dilutive effect of stock options number of shares (in shares)	116,000	114,000
Dilutive effect of stock options (in dollars per share)	$ 0.00	$ (0.01)
Diluted EPS
Diluted EPS	$ 32,969,000	$ 30,739,000
Shares outstanding dilutive (in shares)	22,816,000	23,982,000
Per share amount diluted (in dollars per share)	$ 1.45	$ 1.28
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)	403,407	452,103