GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	$ 91,316	$ 61,159	$ 169,456	$ 113,747
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	(52,962)	(30,821)	(62,582)	(1,259)
Realized loss included in net earnings during the period			(5,194)
Foreign currency translation adjustment	(52,962)	(30,821)	(67,776)	(1,259)
Unrealized loss on cash flow hedge:
Amortization cost included in interest expense	100	100	200	200
Loss arising during the period	100	100	200	200
Actuarial gain (loss) in defined benefit pension plan liability	42	(1,238)	(894)	633
Other comprehensive income (loss)	(52,820)	(31,959)	(68,470)	(426)
Comprehensive income	38,496	29,200	100,986	113,321
Comprehensive income attributable to noncontrolling interests	1,549	2,533	3,189	(2,481)
Comprehensive income attributable to Valmont Industries, Inc.	40,045	31,733	104,175	110,840
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	89,563	59,980	167,132	112,305
Unrealized loss on cash flow hedge:
Amortization cost included in interest expense	100	100	200	200
Loss arising during the period	100	100	200	200
Equity in other comprehensive income	(49,618)	(28,347)	(63,157)	(1,665)
Other comprehensive income (loss)	(49,518)	(28,247)	(62,957)	(1,465)
Comprehensive income	40,045	31,733	104,175	110,840
Comprehensive income attributable to Valmont Industries, Inc.	40,045	31,733	104,175	110,840
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	32,003	23,307	59,510	45,379
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	65,807	14,123	27,486	(2,244)
Foreign currency translation adjustment	65,807	14,123	27,486	(2,244)
Unrealized loss on cash flow hedge:
Other comprehensive income (loss)	65,807	14,123	27,486	(2,244)
Comprehensive income	97,810	37,430	86,996	43,135
Comprehensive income attributable to Valmont Industries, Inc.	97,810	37,430	86,996	43,135
Non-Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	38,550	32,381	67,811	55,613
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	(118,769)	(38,433)	(90,068)	7,496
Realized loss included in net earnings during the period			(5,194)
Foreign currency translation adjustment	(118,769)	(38,433)	(95,262)	7,496
Unrealized loss on cash flow hedge:
Actuarial gain (loss) in defined benefit pension plan liability	42	(1,238)	(894)	633
Other comprehensive income (loss)	(118,727)	(39,671)	(96,156)	8,129
Comprehensive income	(80,177)	(7,290)	(28,345)	63,742
Comprehensive income attributable to noncontrolling interests	1,549	2,533	3,189	(2,481)
Comprehensive income attributable to Valmont Industries, Inc.	(78,628)	(4,757)	(25,156)	61,261
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	(68,800)	(54,509)	(124,997)	(99,550)
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period		(6,511)		(6,511)
Foreign currency translation adjustment		(6,511)		(6,511)
Unrealized loss on cash flow hedge:
Equity in other comprehensive income	49,618	28,347	63,157	1,665
Other comprehensive income (loss)	49,618	21,836	63,157	(4,846)
Comprehensive income	(19,182)	(32,673)	(61,840)	(104,396)
Comprehensive income attributable to Valmont Industries, Inc.	$ (19,182)	$ (32,673)	$ (61,840)	$ (104,396)