Earnings Per Share (Details) (USD $) In Thousands, except Per Share data	3 Months Ended	9 Months Ended
Sep. 24, 2011	Sep. 25, 2010	Sep. 24, 2011	Sep. 25, 2010
Basic EPS
Net earnings attributable to Valmont Industries, Inc, basic	$ 42,141	$ 25,935	$ 113,577	$ 59,513
Shares outstanding basic (in shares)	26,351	26,133	26,318	26,084
Per share amount basic (in dollars per share)	$ 1.60	$ 0.99	$ 4.32	$ 2.28
Dilutive Effect of Stock Options
Dilutive effect of stock options number of shares (in shares)	228	271	249	336
Dilutive effect of stock options (in dollars per share)	$ (0.01)	$ (0.01)	$ (0.04)	$ (0.03)
Diluted EPS
Net earnings attributable to Valmont Industries, Inc, diluted	$ 42,141	$ 25,935	$ 113,577	$ 59,513
Shares outstanding dilutive (in shares)	26,579	26,404	26,567	26,420
Per share amount diluted (in dollars per share)	$ 1.59	$ 0.98	$ 4.28	$ 2.25
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)	218,007	403,867	218,007	403,867

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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