GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 4) (USD $) In Thousands, unless otherwise specified	Jun. 29, 2013	Dec. 29, 2012	Jun. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 490,477	$ 414,129	$ 328,381	$ 362,894
Receivables, net	513,766	515,902
Inventories	413,408	412,384
Prepaid expenses	33,587	25,144
Refundable and deferred income taxes	68,168	58,381
Total current assets	1,519,406	1,425,940
Property, plant and equipment, at cost	1,018,988	994,774
Less accumulated depreciation and amortization	488,506	482,162
Net property, plant and equipment	530,482	512,612
Goodwill	332,367	330,791
Other intangible assets	168,470	172,270
Other assets	100,898	126,938
Total assets	2,651,623	2,568,551
Current liabilities:
Current installments of long-term debt	457	224
Notes payable to banks	16,004	13,375
Accounts payable	212,097	212,424
Accrued employee compensation and benefits	100,536	101,905
Accrued expenses	80,988	78,503
Dividends payable	6,693	6,002
Total current liabilities	416,775	412,433
Deferred income taxes	80,151	88,300
Long-term debt, excluding current installments	471,662	472,593
Defined benefit pension liability	98,707	112,043
Deferred compensation	37,117	31,920
Other noncurrent liabilities	48,854	44,252
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,458,326	1,300,529
Accumulated other comprehensive income (loss)	(19,019)	43,938
Treasury stock	(21,317)	(22,455)
Total Valmont Industries, Inc. shareholders' equity	1,445,890	1,349,912
Noncontrolling interest in consolidated subsidiaries	52,467	57,098
Total shareholders' equity	1,498,357	1,407,010	1,307,839	1,197,911
Total liabilities and shareholders' equity	2,651,623	2,568,551
Parent
Current assets:
Cash and cash equivalents	135,336	40,926	23,542	27,545
Receivables, net	143,707	144,161
Inventories	135,396	146,619
Prepaid expenses	6,573	7,153
Refundable and deferred income taxes	38,155	29,359
Total current assets	459,167	368,218
Property, plant and equipment, at cost	476,731	456,497
Less accumulated depreciation and amortization	296,524	288,226
Net property, plant and equipment	180,207	168,271
Goodwill	20,108	20,108
Other intangible assets	419	499
Investment in subsidiaries and intercompany accounts	1,446,491	1,456,159
Other assets	36,588	32,511
Total assets	2,142,980	2,045,766
Current liabilities:
Current installments of long-term debt	188	189
Accounts payable	66,559	72,610
Accrued employee compensation and benefits	58,734	61,572
Accrued expenses	37,575	30,641
Dividends payable	6,693	6,002
Total current liabilities	169,749	171,014
Deferred income taxes	19,182	23,305
Long-term debt, excluding current installments	470,919	471,828
Deferred compensation	29,689	25,200
Other noncurrent liabilities	7,551	4,507
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,458,326	1,300,529
Accumulated other comprehensive income (loss)	(19,019)	43,938
Treasury stock	(21,317)	(22,455)
Total Valmont Industries, Inc. shareholders' equity	1,445,890	1,349,912
Total shareholders' equity	1,445,890	1,349,912
Total liabilities and shareholders' equity	2,142,980	2,045,766
Guarantors
Current assets:
Cash and cash equivalents	29,738	83,203	40,473	18,257
Receivables, net	81,159	86,403
Inventories	70,345	71,988
Prepaid expenses	712	1,029
Refundable and deferred income taxes	5,605	6,904
Total current assets	187,559	249,527
Property, plant and equipment, at cost	141,114	122,937
Less accumulated depreciation and amortization	58,723	55,239
Net property, plant and equipment	82,391	67,698
Goodwill	107,542	107,542
Other intangible assets	50,869	53,517
Investment in subsidiaries and intercompany accounts	1,348,693	1,246,777
Total assets	1,777,054	1,725,061
Current liabilities:
Accounts payable	19,128	22,006
Accrued employee compensation and benefits	9,046	10,530
Accrued expenses	4,227	4,674
Income taxes payable		31
Total current liabilities	32,401	37,241
Deferred income taxes	28,254	27,851
Long-term debt, excluding current installments	532,852	599,873
Shareholders' equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	150,286	150,286
Retained earnings	526,750	467,240
Accumulated other comprehensive income (loss)	48,561	(15,380)
Total Valmont Industries, Inc. shareholders' equity	1,183,547	1,060,096
Total shareholders' equity	1,183,547	1,060,096
Total liabilities and shareholders' equity	1,777,054	1,725,061
Non-Guarantors
Current assets:
Cash and cash equivalents	325,403	290,000	264,366	317,092
Receivables, net	288,900	285,338
Inventories	207,667	193,777
Prepaid expenses	26,302	16,962
Refundable and deferred income taxes	24,408	22,118
Total current assets	872,680	808,195
Property, plant and equipment, at cost	401,143	415,340
Less accumulated depreciation and amortization	133,259	138,697
Net property, plant and equipment	267,884	276,643
Goodwill	204,717	203,141
Other intangible assets	117,182	118,254
Investment in subsidiaries and intercompany accounts	556,568	615,152
Other assets	64,310	94,427
Total assets	2,083,341	2,115,812
Current liabilities:
Current installments of long-term debt	269	35
Notes payable to banks	16,004	13,375
Accounts payable	126,410	117,808
Accrued employee compensation and benefits	32,756	29,803
Accrued expenses	39,186	43,188
Income taxes payable		669
Total current liabilities	214,625	204,878
Deferred income taxes	32,715	37,144
Long-term debt, excluding current installments	743	765
Defined benefit pension liability	98,707	112,043
Deferred compensation	7,428	6,720
Other noncurrent liabilities	41,303	39,745
Shareholders' equity:
Common stock of $1 par value	254,982	254,982
Additional paid-in capital	894,239	893,274
Retained earnings	505,878	443,337
Accumulated other comprehensive income (loss)	(19,746)	65,826
Total Valmont Industries, Inc. shareholders' equity	1,635,353	1,657,419
Noncontrolling interest in consolidated subsidiaries	52,467	57,098
Total shareholders' equity	1,687,820	1,714,517
Total liabilities and shareholders' equity	2,083,341	2,115,812
Eliminations
Current assets:
Investment in subsidiaries and intercompany accounts	(3,351,752)	(3,318,088)
Total assets	(3,351,752)	(3,318,088)
Current liabilities:
Income taxes payable		(700)
Total current liabilities		(700)
Long-term debt, excluding current installments	(532,852)	(599,873)
Shareholders' equity:
Common stock of $1 par value	(712,932)	(712,932)
Additional paid-in capital	(1,044,525)	(1,043,560)
Retained earnings	(1,032,628)	(910,577)
Accumulated other comprehensive income (loss)	(28,815)	(50,446)
Total Valmont Industries, Inc. shareholders' equity	(2,818,900)	(2,717,515)
Total shareholders' equity	(2,818,900)	(2,717,515)
Total liabilities and shareholders' equity	$ (3,351,752)	$ (3,318,088)