GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION - Condensed Consolidated Statements of Earnings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 26, 2016	Mar. 28, 2015
GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION
Parent company's percentage ownership of Guarantors	100.00%
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	$ 596,605	$ 670,398
Cost of sales	435,636	504,944
Gross profit	160,969	165,454
Selling, general and administrative expenses	98,604	107,771
Operating income	62,365	57,683
Other income (expense):
Interest expense	(11,054)	(11,128)
Interest income	811	874
Other	(1,678)	1,016
Total other income (expenses)	(11,921)	(9,238)
Earnings before income taxes	50,444	48,445
Income tax expense (benefit):
Current	10,514	11,774
Deferred income taxes	5,759	5,164
Total income tax expense (benefit)	16,273	16,938
Earnings before equity in earnings of nonconsolidated subsidiaries	34,171	31,507
Equity in earnings of nonconsolidated subsidiaries	0	0
Net earnings	34,171	31,507
Less: Earnings attributable to noncontrolling interests	(1,202)	(768)
Net earnings attributable to Valmont Industries, Inc.	32,969	30,739
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	285,038	329,131
Cost of sales	207,861	249,867
Gross profit	77,177	79,264
Selling, general and administrative expenses	42,494	48,042
Operating income	34,683	31,222
Other income (expense):
Interest expense	(10,930)	(10,832)
Interest income	67	9
Other	(375)	(649)
Total other income (expenses)	(11,238)	(11,472)
Earnings before income taxes	23,445	19,750
Income tax expense (benefit):
Current	5,583	1,392
Deferred income taxes	2,419	5,469
Total income tax expense (benefit)	8,002	6,861
Earnings before equity in earnings of nonconsolidated subsidiaries	15,443	12,889
Equity in earnings of nonconsolidated subsidiaries	17,526	17,850
Net earnings	32,969	30,739
Less: Earnings attributable to noncontrolling interests	0	0
Net earnings attributable to Valmont Industries, Inc.	32,969	30,739
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	91,526	95,948
Cost of sales	67,862	74,896
Gross profit	23,664	21,052
Selling, general and administrative expenses	11,430	11,297
Operating income	12,234	9,755
Other income (expense):
Interest expense	0	0
Interest income	25	2
Other	12	(24)
Total other income (expenses)	37	(22)
Earnings before income taxes	12,271	9,733
Income tax expense (benefit):
Current	2,572	4,627
Deferred income taxes	2,149	(533)
Total income tax expense (benefit)	4,721	4,094
Earnings before equity in earnings of nonconsolidated subsidiaries	7,550	5,639
Equity in earnings of nonconsolidated subsidiaries	2,113	4,305
Net earnings	9,663	9,944
Less: Earnings attributable to noncontrolling interests	0	0
Net earnings attributable to Valmont Industries, Inc.	9,663	9,944
Non- Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	272,114	302,236
Cost of sales	211,393	236,985
Gross profit	60,721	65,251
Selling, general and administrative expenses	44,680	48,432
Operating income	16,041	16,819
Other income (expense):
Interest expense	(124)	(296)
Interest income	719	863
Other	(1,315)	1,689
Total other income (expenses)	(720)	2,256
Earnings before income taxes	15,321	19,075
Income tax expense (benefit):
Current	2,479	5,797
Deferred income taxes	1,191	228
Total income tax expense (benefit)	3,670	6,025
Earnings before equity in earnings of nonconsolidated subsidiaries	11,651	13,050
Equity in earnings of nonconsolidated subsidiaries	0	0
Net earnings	11,651	13,050
Less: Earnings attributable to noncontrolling interests	(1,202)	(768)
Net earnings attributable to Valmont Industries, Inc.	10,449	12,282
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	(52,073)	(56,917)
Cost of sales	(51,480)	(56,804)
Gross profit	(593)	(113)
Selling, general and administrative expenses	0	0
Operating income	(593)	(113)
Other income (expense):
Interest expense	0	0
Interest income	0	0
Other	0	0
Total other income (expenses)	0	0
Earnings before income taxes	(593)	(113)
Income tax expense (benefit):
Current	(120)	(42)
Deferred income taxes	0	0
Total income tax expense (benefit)	(120)	(42)
Earnings before equity in earnings of nonconsolidated subsidiaries	(473)	(71)
Equity in earnings of nonconsolidated subsidiaries	(19,639)	(22,155)
Net earnings	(20,112)	(22,226)
Less: Earnings attributable to noncontrolling interests	0	0
Net earnings attributable to Valmont Industries, Inc.	$ (20,112)	$ (22,226)