GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 28, 2015	Mar. 29, 2014
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	$ 670,398us-gaap_SalesRevenueNet	$ 751,740us-gaap_SalesRevenueNet
Cost of sales	504,944us-gaap_CostOfRevenue	544,758us-gaap_CostOfRevenue
Gross profit	165,454us-gaap_GrossProfit	206,982us-gaap_GrossProfit
Selling, general and administrative expenses	107,771	108,134
Operating income	57,683us-gaap_OperatingIncomeLoss	98,848us-gaap_OperatingIncomeLoss
Other income (expense):
Interest expense	(11,128)us-gaap_InterestExpense	(8,197)us-gaap_InterestExpense
Interest income	874us-gaap_InvestmentIncomeInterest	1,739us-gaap_InvestmentIncomeInterest
Other	1,016us-gaap_OtherNonoperatingIncomeExpense	(5,812)us-gaap_OtherNonoperatingIncomeExpense
Total other income (expenses)	(9,238)us-gaap_NonoperatingIncomeExpense	(12,270)us-gaap_NonoperatingIncomeExpense
Earnings before income taxes	48,445	86,578
Income tax expense (benefit):
Current	11,774us-gaap_CurrentIncomeTaxExpenseBenefit	32,938us-gaap_CurrentIncomeTaxExpenseBenefit
Deferred	5,164us-gaap_DeferredIncomeTaxExpenseBenefit	(2,923)us-gaap_DeferredIncomeTaxExpenseBenefit
Total income tax expense (benefit)	16,938us-gaap_IncomeTaxExpenseBenefit	30,015us-gaap_IncomeTaxExpenseBenefit
Earnings before equity in earnings of nonconsolidated subsidiaries	31,507	56,563
Net earnings	31,507us-gaap_ProfitLoss	56,563us-gaap_ProfitLoss
Less: Earnings attributable to noncontrolling interests	(768)	(583)
Net earnings attributable to Valmont Industries, Inc.	30,739	55,980
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	329,131	376,642
Cost of sales	249,867	271,759
Gross profit	79,264	104,883
Selling, general and administrative expenses	48,042	47,790
Operating income	31,222	57,093
Other income (expense):
Interest expense	(10,832)	(7,675)
Interest income	9	20
Other	(649)	67
Total other income (expenses)	(11,472)	(7,588)
Earnings before income taxes	19,750	49,505
Income tax expense (benefit):
Current	1,392	19,878
Deferred	5,469	(1,843)
Total income tax expense (benefit)	6,861	18,035
Earnings before equity in earnings of nonconsolidated subsidiaries	12,889	31,470
Equity in earnings of nonconsolidated subsidiaries	17,850	24,510
Net earnings	30,739	55,980
Net earnings attributable to Valmont Industries, Inc.	30,739	55,980
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	95,948	135,897
Cost of sales	74,896	99,816
Gross profit	21,052	36,081
Selling, general and administrative expenses	11,297	12,991
Operating income	9,755	23,090
Other income (expense):
Interest income	2	183
Other	(24)	(492)
Total other income (expenses)	(22)	(309)
Earnings before income taxes	9,733	22,781
Income tax expense (benefit):
Current	4,627	8,054
Deferred	(533)	(412)
Total income tax expense (benefit)	4,094	7,642
Earnings before equity in earnings of nonconsolidated subsidiaries	5,639	15,139
Equity in earnings of nonconsolidated subsidiaries	4,305	545
Net earnings	9,944	15,684
Net earnings attributable to Valmont Industries, Inc.	9,944	15,684
Non-Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	302,236	300,281
Cost of sales	236,985	234,634
Gross profit	65,251	65,647
Selling, general and administrative expenses	48,432	47,353
Operating income	16,819	18,294
Other income (expense):
Interest expense	(296)	(522)
Interest income	863	1,536
Other	1,689	(5,387)
Total other income (expenses)	2,256	(4,373)
Earnings before income taxes	19,075	13,921
Income tax expense (benefit):
Current	5,797	4,902
Deferred	228	(668)
Total income tax expense (benefit)	6,025	4,234
Earnings before equity in earnings of nonconsolidated subsidiaries	13,050	9,687
Net earnings	13,050	9,687
Less: Earnings attributable to noncontrolling interests	(768)	(583)
Net earnings attributable to Valmont Industries, Inc.	12,282	9,104
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	(56,917)	(61,080)
Cost of sales	(56,804)	(61,451)
Gross profit	(113)	371
Operating income	(113)	371
Other income (expense):
Earnings before income taxes	(113)	371
Income tax expense (benefit):
Current	(42)	104
Total income tax expense (benefit)	(42)	104
Earnings before equity in earnings of nonconsolidated subsidiaries	(71)	267
Equity in earnings of nonconsolidated subsidiaries	(22,155)	(25,055)
Net earnings	(22,226)	(24,788)
Net earnings attributable to Valmont Industries, Inc.	$ (22,226)	$ (24,788)

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