Guarantor/Non-Guarantor Financial Information (Details 3) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009	Dec. 27, 2008
Current assets:
Cash and cash equivalents	$ 362,894	$ 346,904	$ 180,786	$ 68,567
Receivables, net	426,683	410,566
Inventories	393,782	280,223
Prepaid expenses	25,765	23,806
Refundable and deferred income taxes	43,819	32,727
Total current assets	1,252,943	1,094,226
Property, plant and equipment, at cost	911,642	865,287
Less accumulated depreciation and amortization	456,765	425,678
Net property, plant and equipment	454,877	439,609
Goodwill	314,662	314,847	178,320
Other intangible assets	168,083	185,535
Investment in subsidiaries and intercompany accounts		21,144
Other assets	115,511	35,382
Total assets	2,306,076	2,090,743	1,302,139
Current liabilities:
Current installments of long-term debt	235	238
Notes payable to banks	11,403	8,824
Accounts payable	234,537	179,814
Accrued expenses	157,128	153,686
Dividends payable	4,767	4,352
Total current liabilities	408,070	346,914
Deferred income taxes	85,497	89,922
Long-term debt, excluding current installments	474,415	468,596
Other noncurrent liabilities	140,183	175,184
Commitments and contingencies (Note 5)
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Common stock, par value (in dollars per share)	$ 1	$ 1
Retained earnings	1,079,698	850,269
Accumulated other comprehensive income	64,052	63,645
Treasury stock	(24,688)	(25,922)
Total Valmont Industries, Inc. shareholders' equity	1,146,962	915,892
Noncontrolling interest in consolidated subsidiaries	50,949	94,235
Total shareholders' equity	1,197,911	1,010,127	808,307	640,976
Total liabilities and shareholders' equity	2,306,076	2,090,743
Parent
Current assets:
Cash and cash equivalents	27,545	8,015	82,017	18,989
Receivables, net	122,409	106,181
Inventories	125,862	63,887
Prepaid expenses	3,448	3,478
Refundable and deferred income taxes	22,053	14,978
Total current assets	301,317	196,539
Property, plant and equipment, at cost	427,398	413,149
Less accumulated depreciation and amortization	283,786	269,831
Net property, plant and equipment	143,612	143,318
Goodwill	20,108	20,108
Other intangible assets	661	823
Investment in subsidiaries and intercompany accounts	1,338,299	1,146,364
Other assets	30,192	24,426
Total assets	1,834,189	1,531,578
Current liabilities:
Current installments of long-term debt	187	187
Accounts payable	85,974	45,854
Accrued expenses	72,341	54,368
Dividends payable	4,767	4,352
Total current liabilities	163,269	104,761
Deferred income taxes	21,891	16,083
Long-term debt, excluding current installments	473,419	467,511
Other noncurrent liabilities	28,648	27,331
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,079,698	850,269
Accumulated other comprehensive income	64,052	63,645
Treasury stock	(24,688)	(25,922)
Total Valmont Industries, Inc. shareholders' equity	1,146,962	915,892
Total shareholders' equity	1,146,962	915,892
Total liabilities and shareholders' equity	1,834,189	1,531,578
Guarantors
Current assets:
Cash and cash equivalents	18,257	619	1,666	1,503
Receivables, net	53,567	50,663
Inventories	77,838	32,030
Prepaid expenses	1,009	920
Refundable and deferred income taxes	6,218	2,597
Total current assets	156,889	86,829
Property, plant and equipment, at cost	107,315	98,019
Less accumulated depreciation and amortization	54,740	50,406
Net property, plant and equipment	52,575	47,613
Goodwill	107,542	107,542
Other intangible assets	59,389	68,310
Investment in subsidiaries and intercompany accounts	695,745	587,231
Total assets	1,072,140	897,525
Current liabilities:
Accounts payable	21,428	15,254
Accrued expenses	14,259	8,147
Total current liabilities	35,687	23,401
Deferred income taxes	27,661	25,004
Shareholders' equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	181,542	181,542
Retained earnings	370,258	209,628
Accumulated other comprehensive income	(958)
Total Valmont Industries, Inc. shareholders' equity	1,008,792	849,120
Total shareholders' equity	1,008,792	849,120
Total liabilities and shareholders' equity	1,072,140	897,525
Non-Guarantors
Current assets:
Cash and cash equivalents	317,092	338,270	97,103	48,075
Receivables, net	250,707	253,722
Inventories	190,082	184,306
Prepaid expenses	21,308	19,408
Refundable and deferred income taxes	15,548	15,152
Total current assets	794,737	810,858
Property, plant and equipment, at cost	376,929	354,119
Less accumulated depreciation and amortization	118,239	105,441
Net property, plant and equipment	258,690	248,678
Goodwill	187,012	187,197
Other intangible assets	108,033	116,402
Investment in subsidiaries and intercompany accounts	596,301	30,017
Other assets	85,319	10,956
Total assets	2,030,092	1,404,108
Current liabilities:
Current installments of long-term debt	48	51
Notes payable to banks	11,403	8,824
Accounts payable	127,135	118,706
Accrued expenses	70,528	91,171
Total current liabilities	209,114	218,752
Deferred income taxes	35,945	48,835
Long-term debt, excluding current installments	996	1,085
Other noncurrent liabilities	111,535	147,853
Shareholders' equity:
Common stock of $1 par value	254,982	2,582
Additional paid-in capital	893,884	156,188
Retained earnings	407,677	670,933
Accumulated other comprehensive income	65,010	63,645
Total Valmont Industries, Inc. shareholders' equity	1,621,553	893,348
Noncontrolling interest in consolidated subsidiaries	50,949	94,235
Total shareholders' equity	1,672,502	987,583
Total liabilities and shareholders' equity	2,030,092	1,404,108
Eliminations
Current assets:
Investment in subsidiaries and intercompany accounts	(2,630,345)	(1,742,468)
Total assets	(2,630,345)	(1,742,468)
Shareholders' equity:
Common stock of $1 par value	(712,932)	(460,532)
Additional paid-in capital	(1,075,426)	(337,730)
Retained earnings	(777,935)	(880,561)
Accumulated other comprehensive income	(64,052)	(63,645)
Total Valmont Industries, Inc. shareholders' equity	(2,630,345)	(1,742,468)
Total shareholders' equity	(2,630,345)	(1,742,468)
Total liabilities and shareholders' equity	$ (2,630,345)	$ (1,742,468)