GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	$ 45,333	$ 189,318	$ 280,460
Foreign currency translation adjustments:
Unrealized translation gains (losses)	(96,694)	(82,275)	(71,698)
Realized loss on sale of investment in foreign entity included in other expense	0	0	5,194
Realized loss on deconsolidation of subsidiary			8,559
Foreign currency translation adjustment	(96,694)	(82,275)	(57,945)
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	74	594	400
Realized (gain) loss included in net earnings	(3,130)	983	0
Unrealized gain (loss) on cash flow hedge	2,855	4,837	0
Derivative adjustment	(201)	6,414	400
Actuarial gain (loss) in defined benefit pension plan	(40,274)	(13,709)	(41,282)
Equity in other comprehensive income	0	0	0
Other comprehensive income (loss)	(137,169)	(89,570)	(98,827)
Comprehensive income (loss)	(91,836)	99,748	181,633
Comprehensive loss (income) attributable to noncontrolling interests	(832)	(2,520)	(9,174)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	(92,668)	97,228	172,459
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	40,117	183,976	278,489
Foreign currency translation adjustments:
Unrealized translation gains (losses)	0	0	0
Realized loss on sale of investment in foreign entity included in other expense			0
Realized loss on deconsolidation of subsidiary			0
Foreign currency translation adjustment	0	0	0
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	74	594	400
Realized (gain) loss included in net earnings	(3,130)	983
Unrealized gain (loss) on cash flow hedge	2,855	4,837
Derivative adjustment	(201)	6,414	400
Actuarial gain (loss) in defined benefit pension plan	0	0	0
Equity in other comprehensive income	(132,584)	(93,162)	(106,430)
Other comprehensive income (loss)	(132,785)	(86,748)	(106,030)
Comprehensive income (loss)	(92,668)	97,228	172,459
Comprehensive loss (income) attributable to noncontrolling interests	0	0	0
Comprehensive income (loss) attributable to Valmont Industries, Inc.	(92,668)	97,228	172,459
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	(10,760)	67,725	97,955
Foreign currency translation adjustments:
Unrealized translation gains (losses)	(15,166)	(51,536)	(4,772)
Realized loss on sale of investment in foreign entity included in other expense			0
Realized loss on deconsolidation of subsidiary			0
Foreign currency translation adjustment	(15,166)	(51,536)	(4,772)
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	0	0	0
Realized (gain) loss included in net earnings	0	0
Unrealized gain (loss) on cash flow hedge	0	0
Derivative adjustment	0	0	0
Actuarial gain (loss) in defined benefit pension plan	0	0	0
Equity in other comprehensive income	0	0	0
Other comprehensive income (loss)	(15,166)	(51,536)	(4,772)
Comprehensive income (loss)	(25,926)	16,189	93,183
Comprehensive loss (income) attributable to noncontrolling interests	0	0	0
Comprehensive income (loss) attributable to Valmont Industries, Inc.	(25,926)	16,189	93,183
Non- Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	(11,241)	85,840	68,597
Foreign currency translation adjustments:
Unrealized translation gains (losses)	(81,528)	(30,739)	(66,926)
Realized loss on sale of investment in foreign entity included in other expense			5,194
Realized loss on deconsolidation of subsidiary			8,559
Foreign currency translation adjustment	(81,528)	(30,739)	(53,173)
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	0	0	0
Realized (gain) loss included in net earnings	0	0
Unrealized gain (loss) on cash flow hedge	0	0
Derivative adjustment	0	0	0
Actuarial gain (loss) in defined benefit pension plan	(40,274)	(13,709)	(41,282)
Equity in other comprehensive income	0	0	0
Other comprehensive income (loss)	(121,802)	(44,448)	(94,455)
Comprehensive income (loss)	(133,043)	41,392	(25,858)
Comprehensive loss (income) attributable to noncontrolling interests	(832)	(2,520)	(9,174)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	(133,875)	38,872	(35,032)
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	27,217	(148,223)	(164,581)
Foreign currency translation adjustments:
Unrealized translation gains (losses)	0	0	0
Realized loss on sale of investment in foreign entity included in other expense			0
Realized loss on deconsolidation of subsidiary			0
Foreign currency translation adjustment	0	0	0
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	0	0	0
Realized (gain) loss included in net earnings	0	0
Unrealized gain (loss) on cash flow hedge	0	0
Derivative adjustment	0	0	0
Actuarial gain (loss) in defined benefit pension plan	0	0	0
Equity in other comprehensive income	132,584	93,162	106,430
Other comprehensive income (loss)	132,584	93,162	106,430
Comprehensive income (loss)	159,801	(55,061)	(58,151)
Comprehensive loss (income) attributable to noncontrolling interests	0	0	0
Comprehensive income (loss) attributable to Valmont Industries, Inc.	$ 159,801	$ (55,061)	$ (58,151)