GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Mar. 30, 2013	Sep. 27, 2014	Sep. 28, 2013
Condensed consolidated financial information for the Company (Parent), the Guarantor subsidiaries and the Non-Guarantor subsidiaries
Net earnings	$ 25,285	$ 58,891		$ 147,700	$ 228,347
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	(59,001)	18,124		(33,495)	(44,458)
Realized (loss) included in net earnings during the period			5,194		5,194
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	383	100		450	300
Realized loss included in net earnings during the period	983			983
Gain on cash flow hedges	4,837			4,837
Actuarial gain (loss) in defined benefit pension plan liability	1,116	857		269	(37)
Other comprehensive income (loss)	(51,682)	19,081		(26,956)	(49,389)
Comprehensive income (loss)	(26,397)	77,972		120,744	178,958
Comprehensive income attributable to noncontrolling interests	89	(2,156)		(1,615)	1,033
Comprehensive income (loss) attributable to Valmont Industries, Inc	(26,308)	75,816		119,129	179,991
Parent
Condensed consolidated financial information for the Company (Parent), the Guarantor subsidiaries and the Non-Guarantor subsidiaries
Net earnings	23,559	56,489		143,515	223,621
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	100	100		300	300
Realized loss included in net earnings during the period	983			983
Gain on cash flow hedges	4,837			4,837
Equity in other comprehensive income	(55,787)	19,227		(30,506)	(43,930)
Other comprehensive income (loss)	(49,867)	19,327		(24,386)	(43,630)
Comprehensive income (loss)	(26,308)	75,816		119,129	179,991
Comprehensive income (loss) attributable to Valmont Industries, Inc	(26,308)	75,816		119,129	179,991
Guarantors
Condensed consolidated financial information for the Company (Parent), the Guarantor subsidiaries and the Non-Guarantor subsidiaries
Net earnings	18,272	13,644		55,359	73,154
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	37,807	30,221		8,492	57,707
Unrealized gain/(loss) on cash flow hedge:
Other comprehensive income (loss)	37,807	30,221		8,492	57,707
Comprehensive income (loss)	56,079	43,865		63,851	130,861
Comprehensive income (loss) attributable to Valmont Industries, Inc	56,079	43,865		63,851	130,861
Non-Guarantors
Condensed consolidated financial information for the Company (Parent), the Guarantor subsidiaries and the Non-Guarantor subsidiaries
Net earnings	36,693	31,261		90,679	99,072
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	(96,808)	(12,097)		(41,987)	(102,165)
Realized (loss) included in net earnings during the period					(5,194)
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	283			150
Actuarial gain (loss) in defined benefit pension plan liability	1,116	857		269	(37)
Other comprehensive income (loss)	(95,409)	(11,240)		(41,568)	(107,396)
Comprehensive income (loss)	(58,716)	20,021		49,111	(8,324)
Comprehensive income attributable to noncontrolling interests	89	(2,156)		(1,615)	1,033
Comprehensive income (loss) attributable to Valmont Industries, Inc	(58,627)	17,865		47,496	(7,291)
Eliminations
Condensed consolidated financial information for the Company (Parent), the Guarantor subsidiaries and the Non-Guarantor subsidiaries
Net earnings	(53,239)	(42,503)		(141,853)	(167,500)
Unrealized gain/(loss) on cash flow hedge:
Equity in other comprehensive income	55,787	(19,227)		30,506	43,930
Other comprehensive income (loss)	55,787	(19,227)		30,506	43,930
Comprehensive income (loss)	2,548	(61,730)		(111,347)	(123,570)
Comprehensive income (loss) attributable to Valmont Industries, Inc	$ 2,548	$ (61,730)		$ (111,347)	$ (123,570)