EARNINGS PER SHARE - Schedule of Reconciliation of Basic and Diluted Earnings Per Share (EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 01, 2023	Mar. 26, 2022
Basic EPS
Net earnings attributable to Valmont Industries, Inc.	$ 74,540	$ 62,311
Weighted average shares outstanding basic (in shares)	21,269	21,279
Per share amount basic (in dollars per share)	$ 3.50	$ 2.93
Dilutive Effect of Stock Options
Dilutive effect of stock options number of shares (in shares)	243	213
Dilutive effect of stock options (in dollars per share)	$ (0.03)	$ (0.03)
Diluted EPS
Net earnings attributable to Valmont Industries, Inc.	$ 74,540	$ 62,311
Weighted average shares outstanding dilutive (in shares)	21,512	21,492
Per share amount diluted (in dollars per share)	$ 3.47	$ 2.90