GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Sep. 24, 2011	Sep. 29, 2012	Sep. 24, 2011
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	$ 729,839	$ 672,192	$ 2,214,504	$ 1,908,750
Cost of sales	537,437	504,802	1,636,393	1,436,885
Gross profit	192,402	167,390	578,111	471,865
Selling, general and administrative expenses	102,020	95,357	307,559	285,912
Operating income	90,382	72,033	270,552	185,953
Other income (expenses):
Interest expense	(8,429)	(7,671)	(23,657)	(26,715)
Interest income	2,093	3,141	6,081	6,919
Other	1,307	(1,670)	907	(776)
Total other income (expenses)	(5,029)	(6,200)	(16,669)	(20,572)
Earnings before income taxes and equity in earnings of nonconsolidated subsidiaries	85,353	65,833	253,883	165,381
Income tax expense (benefit):
Current	27,928	25,119	90,942	62,156
Deferred	519	(1,346)	(3,937)	(11,544)
Total income tax expense (benefit)	28,447	23,773	87,005	50,612
Earnings before equity in earnings of nonconsolidated subsidiaries	56,906	42,060	166,878	114,769
Equity in earnings/(losses) of nonconsolidated subsidiaries	1,536	2,354	5,311	4,509
Net earnings	58,442	44,414	172,189	119,278
Other comprehensive income (loss)	25,809	(54,182)	25,383	(23,708)
Comprehensive income (loss)	84,251	(9,768)	197,572	95,570
Less: Comprehensive income attributable to noncontrolling interests	(2,958)	2,418	(5,439)	(3,870)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	81,293	(7,350)	192,133	91,700
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	301,667	277,350	1,014,150	842,493
Cost of sales	226,539	205,787	743,608	627,802
Gross profit	75,128	71,563	270,542	214,691
Selling, general and administrative expenses	41,747	37,169	128,781	115,422
Operating income	33,381	34,394	141,761	99,269
Other income (expenses):
Interest expense	(8,215)	(7,562)	(23,470)	(26,417)
Interest income	15	9	29	43
Other	883	(1,297)	1,888	(1,105)
Total other income (expenses)	(7,317)	(8,850)	(21,553)	(27,479)
Earnings before income taxes and equity in earnings of nonconsolidated subsidiaries	26,064	25,544	120,208	71,790
Income tax expense (benefit):
Current	8,096	12,153	44,644	31,505
Deferred	(1,063)	(1,397)	(3,832)	(5,307)
Total income tax expense (benefit)	7,033	10,756	40,812	26,198
Earnings before equity in earnings of nonconsolidated subsidiaries	19,031	14,788	79,396	45,592
Equity in earnings/(losses) of nonconsolidated subsidiaries	37,700	27,353	89,640	67,985
Net earnings	56,731	42,141	169,036	113,577
Other comprehensive income (loss)	24,562	(49,491)	23,097	(21,877)
Comprehensive income (loss)	81,293	(7,350)	192,133	91,700
Comprehensive income (loss) attributable to Valmont Industries, Inc.	81,293	(7,350)	192,133	91,700
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	160,318	98,619	441,189	259,733
Cost of sales	127,116	83,008	352,416	209,827
Gross profit	33,202	15,611	88,773	49,906
Selling, general and administrative expenses	13,449	11,212	40,414	33,473
Operating income	19,753	4,399	48,359	16,433
Other income (expenses):
Interest expense	(12,635)		(37,136)
Interest income	398	204	721	204
Other	15	12	40	42
Total other income (expenses)	(12,222)	216	(36,375)	246
Earnings before income taxes and equity in earnings of nonconsolidated subsidiaries	7,531	4,615	11,984	16,679
Income tax expense (benefit):
Current	4,786	(724)	10,082	4,552
Deferred	(558)	2,710	(419)	1,742
Total income tax expense (benefit)	4,228	1,986	9,663	6,294
Earnings before equity in earnings of nonconsolidated subsidiaries	3,303	2,629	2,321	10,385
Equity in earnings/(losses) of nonconsolidated subsidiaries	18,557	14,705	64,918	35,042
Net earnings	21,860	17,334	67,239	45,427
Other comprehensive income (loss)	(14,977)		(17,221)
Comprehensive income (loss)	6,883	17,334	50,018	45,427
Comprehensive income (loss) attributable to Valmont Industries, Inc.	6,883	17,334	50,018	45,427
Non-Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	350,837	352,928	977,950	947,843
Cost of sales	266,532	272,671	757,829	740,621
Gross profit	84,305	80,257	220,121	207,222
Selling, general and administrative expenses	46,824	46,976	138,364	137,017
Operating income	37,481	33,281	81,757	70,205
Other income (expenses):
Interest expense	(213)	(109)	(186)	(298)
Interest income	14,314	2,928	42,466	6,672
Other	409	(385)	(1,021)	287
Total other income (expenses)	14,510	2,434	41,259	6,661
Earnings before income taxes and equity in earnings of nonconsolidated subsidiaries	51,991	35,715	123,016	76,866
Income tax expense (benefit):
Current	15,701	13,690	36,871	26,099
Deferred	2,140	(2,659)	314	(7,979)
Total income tax expense (benefit)	17,841	11,031	37,185	18,120
Earnings before equity in earnings of nonconsolidated subsidiaries	34,150	24,684	85,831	58,746
Equity in earnings/(losses) of nonconsolidated subsidiaries	918	2,127	4,850	4,247
Net earnings	35,068	26,811	90,681	62,993
Other comprehensive income (loss)	41,046	(57,464)	49,175	(23,708)
Comprehensive income (loss)	76,114	(30,653)	139,856	39,285
Less: Comprehensive income attributable to noncontrolling interests	(2,958)	2,418	(5,439)	(3,870)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	73,156	(28,235)	134,417	35,415
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net sales	(82,983)	(56,705)	(218,785)	(141,319)
Cost of sales	(82,750)	(56,664)	(217,460)	(141,365)
Gross profit	(233)	(41)	(1,325)	46
Operating income	(233)	(41)	(1,325)	46
Other income (expenses):
Interest expense	12,634		37,135
Interest income	(12,634)		(37,135)
Earnings before income taxes and equity in earnings of nonconsolidated subsidiaries	(233)	(41)	(1,325)	46
Income tax expense (benefit):
Current	(655)		(655)
Total income tax expense (benefit)	(655)		(655)
Earnings before equity in earnings of nonconsolidated subsidiaries	422	(41)	(670)	46
Equity in earnings/(losses) of nonconsolidated subsidiaries	(55,639)	(41,831)	(154,097)	(102,765)
Net earnings	(55,217)	(41,872)	(154,767)	(102,719)
Other comprehensive income (loss)	(24,822)	52,773	(29,668)	21,877
Comprehensive income (loss)	(80,039)	10,901	(184,435)	(80,842)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	$ (80,039)	$ 10,901	$ (184,435)	$ (80,842)