GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	$ 58,891	$ 58,442	$ 228,347	$ 172,189
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	18,124	23,747	(44,458)	22,488
Realized (loss) included in net earnings during the period			(5,194)
Foreign currency translation adjustment	18,124	23,747	(49,652)	22,488
Unrealized loss on cash flow hedge:
Amortization cost included in interest expense	100	100	300	300
Loss arising during the period	100	100	300	300
Actuarial gain (loss) in defined benefit pension plan liability	857	1,962	(37)	2,595
Other comprehensive income (loss)	19,081	25,809	(49,389)	25,383
Comprehensive income	77,972	84,251	178,958	197,572
Comprehensive income attributable to noncontrolling interests	(2,156)	(2,958)	1,033	(5,439)
Comprehensive income attributable to Valmont Industries, Inc.	75,816	81,293	179,991	192,133
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	56,489	56,731	223,621	169,036
Unrealized loss on cash flow hedge:
Amortization cost included in interest expense	100	100	300	300
Loss arising during the period	100	100	300	300
Equity in other comprehensive income	19,227	24,462	(43,930)	22,797
Other comprehensive income (loss)	19,327	24,562	(43,630)	23,097
Comprehensive income	75,816	81,293	179,991	192,133
Comprehensive income attributable to Valmont Industries, Inc.	75,816	81,293	179,991	192,133
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	13,644	21,860	73,154	67,239
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	30,221	(14,977)	57,707	(17,221)
Foreign currency translation adjustment	30,221	(14,977)	57,707	(17,221)
Unrealized loss on cash flow hedge:
Other comprehensive income (loss)	30,221	(14,977)	57,707	(17,221)
Comprehensive income	43,865	6,883	130,861	50,018
Comprehensive income attributable to Valmont Industries, Inc.	43,865	6,883	130,861	50,018
Non-Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	31,261	35,068	99,072	90,681
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period	(12,097)	39,084	(102,165)	46,580
Realized (loss) included in net earnings during the period			(5,194)
Foreign currency translation adjustment	(12,097)	39,084	(107,359)	46,580
Unrealized loss on cash flow hedge:
Actuarial gain (loss) in defined benefit pension plan liability	857	1,962	(37)	2,595
Other comprehensive income (loss)	(11,240)	41,046	(107,396)	49,175
Comprehensive income	20,021	76,114	(8,324)	139,856
Comprehensive income attributable to noncontrolling interests	(2,156)	(2,958)	1,033	(5,439)
Comprehensive income attributable to Valmont Industries, Inc.	17,865	73,156	(7,291)	134,417
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	(42,503)	(55,217)	(167,500)	(154,767)
Foreign currency translation adjustments:
Unrealized gains (losses) arising during the period		(360)		(6,871)
Foreign currency translation adjustment		(360)		(6,871)
Unrealized loss on cash flow hedge:
Equity in other comprehensive income	(19,227)	(24,462)	43,930	(22,797)
Other comprehensive income (loss)	(19,227)	(24,822)	43,930	(29,668)
Comprehensive income	(61,730)	(80,039)	(123,570)	(184,435)
Comprehensive income attributable to Valmont Industries, Inc.	$ (61,730)	$ (80,039)	$ (123,570)	$ (184,435)