GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 3) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 26, 2011	Dec. 25, 2010
Current assets:
Cash and cash equivalents	$ 339,568	$ 362,894	$ 358,271	$ 346,904
Receivables, net	450,280	426,683
Inventories	440,600	393,782
Prepaid expenses	27,881	25,765
Refundable and deferred income taxes	42,263	43,819
Total current assets	1,300,592	1,252,943
Property, plant and equipment, at cost	945,457	911,642
Less accumulated depreciation and amortization	476,125	456,765
Net property, plant and equipment	469,332	454,877
Goodwill	320,617	314,662
Other intangible assets	168,259	168,083
Other assets	124,169	115,511
Total assets	2,382,969	2,306,076
Current liabilities:
Current installments of long-term debt	264	235
Notes payable to banks	12,293	11,403
Accounts payable	235,743	234,537
Accrued expenses	151,386	157,128
Dividends payable	4,778	4,767
Total current liabilities	404,464	408,070
Deferred income taxes	86,798	85,497
Long-term debt, excluding current installments	474,015	474,415
Other noncurrent liabilities	136,689	140,183
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Common stock, par value (in dollars per share)	$ 1	$ 1
Retained earnings	1,130,655	1,079,698
Accumulated other comprehensive income	90,834	64,052
Treasury stock	(23,918)	(24,688)
Total Valmont Industries, Inc. shareholders' equity	1,225,471	1,146,962
Noncontrolling interest in consolidated subsidiaries	55,532	50,949
Total shareholders' equity	1,281,003	1,197,911	1,053,457	1,010,127
Total liabilities and shareholders' equity	2,382,969	2,306,076
Parent
Current assets:
Cash and cash equivalents	24,482	27,545	15,380	8,015
Receivables, net	139,551	122,409
Inventories	128,643	125,862
Prepaid expenses	1,966	3,448
Refundable and deferred income taxes	20,889	22,053
Total current assets	315,531	301,317
Property, plant and equipment, at cost	435,785	427,398
Less accumulated depreciation and amortization	287,559	283,786
Net property, plant and equipment	148,226	143,612
Goodwill	20,108	20,108
Other intangible assets	620	661
Investment in subsidiaries and intercompany accounts	1,401,488	1,338,299
Other assets	32,349	30,192
Total assets	1,918,322	1,834,189
Current liabilities:
Current installments of long-term debt	187	187
Accounts payable	87,990	85,974
Accrued expenses	73,720	72,341
Dividends payable	4,778	4,767
Total current liabilities	166,675	163,269
Deferred income taxes	20,922	21,891
Long-term debt, excluding current installments	473,077	473,419
Other noncurrent liabilities	32,177	28,648
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,130,655	1,079,698
Accumulated other comprehensive income	90,834	64,052
Treasury stock	(23,918)	(24,688)
Total Valmont Industries, Inc. shareholders' equity	1,225,471	1,146,962
Total shareholders' equity	1,225,471	1,146,962
Total liabilities and shareholders' equity	1,918,322	1,834,189
Guarantors
Current assets:
Cash and cash equivalents	16,405	18,257	1,181	619
Receivables, net	59,989	53,567
Inventories	83,101	77,838
Prepaid expenses	945	1,009
Refundable and deferred income taxes	5,051	6,218
Total current assets	165,491	156,889
Property, plant and equipment, at cost	110,066	107,315
Less accumulated depreciation and amortization	56,418	54,740
Net property, plant and equipment	53,648	52,575
Goodwill	107,542	107,542
Other intangible assets	57,921	59,389
Investment in subsidiaries and intercompany accounts	1,256,907	695,745
Total assets	1,641,509	1,072,140
Current liabilities:
Accounts payable	21,299	21,428
Accrued expenses	8,996	14,259
Total current liabilities	30,295	35,687
Deferred income taxes	27,664	27,661
Long-term debt, excluding current installments	600,309
Shareholders' equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	150,286	181,542
Retained earnings	392,330	370,258
Accumulated other comprehensive income	(17,325)	(958)
Total Valmont Industries, Inc. shareholders' equity	983,241	1,008,792
Total shareholders' equity	983,241	1,008,792
Total liabilities and shareholders' equity	1,641,509	1,072,140
Non-Guarantors
Current assets:
Cash and cash equivalents	298,681	317,092	341,710	338,270
Receivables, net	250,740	250,707
Inventories	228,856	190,082
Prepaid expenses	24,970	21,308
Refundable and deferred income taxes	16,323	15,548
Total current assets	819,570	794,737
Property, plant and equipment, at cost	399,606	376,929
Less accumulated depreciation and amortization	132,148	118,239
Net property, plant and equipment	267,458	258,690
Goodwill	192,967	187,012
Other intangible assets	109,718	108,033
Investment in subsidiaries and intercompany accounts	612,826	596,301
Other assets	91,820	85,319
Total assets	2,094,359	2,030,092
Current liabilities:
Current installments of long-term debt	77	48
Notes payable to banks	12,293	11,403
Accounts payable	126,454	127,135
Accrued expenses	68,670	70,528
Total current liabilities	207,494	209,114
Deferred income taxes	38,212	35,945
Long-term debt, excluding current installments	938	996
Other noncurrent liabilities	104,512	111,535
Shareholders' equity:
Common stock of $1 par value	254,982	254,982
Additional paid-in capital	893,884	893,884
Retained earnings	430,646	407,677
Accumulated other comprehensive income	108,159	65,010
Total Valmont Industries, Inc. shareholders' equity	1,687,671	1,621,553
Noncontrolling interest in consolidated subsidiaries	55,532	50,949
Total shareholders' equity	1,743,203	1,672,502
Total liabilities and shareholders' equity	2,094,359	2,030,092
Eliminations
Current assets:
Investment in subsidiaries and intercompany accounts	(3,271,221)	(2,630,345)
Total assets	(3,271,221)	(2,630,345)
Current liabilities:
Long-term debt, excluding current installments	(600,309)
Shareholders' equity:
Common stock of $1 par value	(712,932)	(712,932)
Additional paid-in capital	(1,044,170)	(1,075,426)
Retained earnings	(822,976)	(777,935)
Accumulated other comprehensive income	(90,834)	(64,052)
Total Valmont Industries, Inc. shareholders' equity	(2,670,912)	(2,630,345)
Total shareholders' equity	(2,670,912)	(2,630,345)
Total liabilities and shareholders' equity	$ (3,271,221)	$ (2,630,345)