GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	$ 280,460	$ 238,916	$ 237,226
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	(71,698)	15,741	(21,976)
Realized loss on sale of foreign entity investment included in other expense	5,194		1,446
Realized loss on deconsolidation of subsidiary	8,559
Foreign currency translation adjustments	(57,945)	15,741	(20,530)
Unrealized loss on cash flow hedge:
Loss arising during the period			(3,568)
Amortization cost included in interest expense	400	400	233
Derivative adjustment	400	400	(3,335)
Actuarial gain (loss) in defined benefit pension plan liability	(41,282)	(35,020)	22,365
Other comprehensive income (loss)	(98,827)	(18,879)	(1,500)
Comprehensive income	181,633	220,037	235,726
Comprehensive income attributable to noncontrolling interests	(9,174)	(6,079)	(7,011)
Comprehensive income attributable to Valmont Industries, Inc.	172,459	213,958	228,715
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	278,489	234,072	228,308
Unrealized loss on cash flow hedge:
Loss arising during the period			(3,568)
Amortization cost included in interest expense	400	400	233
Derivative adjustment	400	400	(3,335)
Equity in other comprehensive income	(106,430)	(20,514)	3,742
Other comprehensive income (loss)	(106,030)	(20,114)	407
Comprehensive income	172,459	213,958	228,715
Comprehensive income attributable to Valmont Industries, Inc.	172,459	213,958	228,715
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	97,954	96,982	142,900
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	81,824	(14,422)	(958)
Foreign currency translation adjustments	81,824	(14,422)	(958)
Unrealized loss on cash flow hedge:
Other comprehensive income (loss)	81,824	(14,422)	(958)
Comprehensive income	179,778	82,560	141,942
Comprehensive income attributable to Valmont Industries, Inc.	179,778	82,560	141,942
Non-Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	105,417	123,333	164,422
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	(153,522)	30,163	(21,018)
Realized loss on sale of foreign entity investment included in other expense	5,194		1,446
Realized loss on deconsolidation of subsidiary	8,559
Foreign currency translation adjustments	(139,769)	30,163	(19,572)
Unrealized loss on cash flow hedge:
Actuarial gain (loss) in defined benefit pension plan liability	(41,282)	(35,020)	22,365
Other comprehensive income (loss)	(181,051)	(4,857)	2,793
Comprehensive income	(75,634)	118,476	167,215
Comprehensive income attributable to noncontrolling interests	(9,174)	(6,079)	(7,011)
Comprehensive income attributable to Valmont Industries, Inc.	(84,808)	112,397	160,204
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	(201,400)	(215,471)	(298,404)
Unrealized loss on cash flow hedge:
Equity in other comprehensive income	106,430	20,514	(3,742)
Other comprehensive income (loss)	106,430	20,514	(3,742)
Comprehensive income	(94,970)	(194,957)	(302,146)
Comprehensive income attributable to Valmont Industries, Inc.	$ (94,970)	$ (194,957)	$ (302,146)