GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 5) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Dec. 28, 2013	Jun. 29, 2013	Dec. 29, 2012
Current assets:
Cash and cash equivalents	$ 455,927	$ 613,706	$ 490,477	$ 414,129
Receivables, net	543,608	515,440
Inventories	381,943	380,000
Prepaid expenses	66,916	22,997
Refundable and deferred income taxes	71,334	65,697
Total current assets	1,519,728	1,597,840
Property, plant and equipment, at cost	1,160,142	1,017,126
Less accumulated depreciation and amortization	521,288	482,916
Net property, plant and equipment	638,854	534,210
Goodwill	368,405	349,632
Other intangible assets	195,359	170,917
Other assets	136,258	123,895
Total assets	2,858,604	2,776,494
Current liabilities:
Current installments of long-term debt	188	202
Notes payable to banks	17,485	19,024
Accounts payable	208,834	216,121
Accrued employee compensation and benefits	95,365	122,967
Accrued expenses	91,631	71,560
Dividends payable	9,930	6,706
Total current liabilities	423,433	436,580
Deferred income taxes	95,674	78,924
Long-term debt, excluding current installments	478,498	470,907
Defined benefit pension liability	143,114	154,397
Deferred compensation	48,292	39,109
Other noncurrent liabilities	54,503	51,731
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,672,287	1,562,670
Accumulated other comprehensive income (loss)	(22,204)	(47,685)
Treasury stock	(95,714)	(20,860)
Total Valmont Industries, Inc. shareholders' equity	1,582,269	1,522,025
Noncontrolling interest in consolidated subsidiaries	32,821	22,821
Total shareholders' equity	1,615,090	1,544,846	1,498,357	1,407,010
Total liabilities and shareholders' equity	2,858,604	2,776,494
Parent
Current assets:
Cash and cash equivalents	63,127	215,576	135,336	40,926
Receivables, net	148,649	139,179
Inventories	123,369	132,953
Prepaid expenses	6,606	4,735
Refundable and deferred income taxes	51,058	41,167
Total current assets	392,809	533,610
Property, plant and equipment, at cost	548,424	522,734
Less accumulated depreciation and amortization	311,358	300,066
Net property, plant and equipment	237,066	222,668
Goodwill	20,108	20,108
Other intangible assets	319	346
Investment in subsidiaries and intercompany accounts	1,578,856	1,417,425
Other assets	40,228	30,759
Total assets	2,269,386	2,224,916
Current liabilities:
Current installments of long-term debt	188	188
Accounts payable	63,503	62,153
Accrued employee compensation and benefits	46,513	76,370
Accrued expenses	33,746	28,362
Dividends payable	9,930	6,706
Total current liabilities	153,880	173,779
Deferred income taxes	13,406	18,983
Long-term debt, excluding current installments	469,216	470,175
Deferred compensation	41,134	32,339
Other noncurrent liabilities	9,481	7,615
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,672,287	1,562,670
Accumulated other comprehensive income (loss)	(22,204)	(47,685)
Treasury stock	(95,714)	(20,860)
Total Valmont Industries, Inc. shareholders' equity	1,582,269	1,522,025
Total shareholders' equity	1,582,269	1,522,025
Total liabilities and shareholders' equity	2,269,386	2,224,916
Guarantors
Current assets:
Cash and cash equivalents	49,455	49,053	29,738	83,203
Receivables, net	73,846	108,646
Inventories	59,580	70,231
Prepaid expenses	690	932
Refundable and deferred income taxes	6,285	8,351
Total current assets	189,856	237,213
Property, plant and equipment, at cost	126,706	125,764
Less accumulated depreciation and amortization	65,166	61,520
Net property, plant and equipment	61,540	64,244
Goodwill	107,542	107,542
Other intangible assets	46,052	48,461
Investment in subsidiaries and intercompany accounts	1,445,118	1,367,308
Total assets	1,850,108	1,824,768
Current liabilities:
Accounts payable	16,471	20,365
Accrued employee compensation and benefits	6,332	13,713
Accrued expenses	6,284	7,315
Total current liabilities	29,087	41,393
Deferred income taxes	28,879	29,279
Long-term debt, excluding current installments	544,497	514,223
Shareholders' equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	150,286	150,286
Retained earnings	602,280	565,193
Accumulated other comprehensive income (loss)	37,129	66,444
Total Valmont Industries, Inc. shareholders' equity	1,247,645	1,239,873
Total shareholders' equity	1,247,645	1,239,873
Total liabilities and shareholders' equity	1,850,108	1,824,768
Non-Guarantors
Current assets:
Cash and cash equivalents	343,345	349,077	325,403	290,000
Receivables, net	321,113	267,615
Inventories	198,994	176,816
Prepaid expenses	59,620	17,330
Refundable and deferred income taxes	13,991	16,179
Total current assets	937,063	827,017
Property, plant and equipment, at cost	485,012	368,628
Less accumulated depreciation and amortization	144,764	121,330
Net property, plant and equipment	340,248	247,298
Goodwill	240,755	221,982
Other intangible assets	148,988	122,110
Investment in subsidiaries and intercompany accounts	509,824	518,059
Other assets	96,030	93,136
Total assets	2,272,908	2,029,602
Current liabilities:
Current installments of long-term debt		14
Notes payable to banks	17,485	19,024
Accounts payable	128,860	133,603
Accrued employee compensation and benefits	42,520	32,884
Accrued expenses	51,601	35,883
Total current liabilities	240,466	221,408
Deferred income taxes	53,389	30,662
Long-term debt, excluding current installments	9,282	732
Defined benefit pension liability	143,114	154,397
Deferred compensation	7,158	6,770
Other noncurrent liabilities	45,022	44,116
Shareholders' equity:
Common stock of $1 par value	254,982	254,982
Additional paid-in capital	1,034,236	891,236
Retained earnings	522,868	517,703
Accumulated other comprehensive income (loss)	(70,430)	(115,225)
Total Valmont Industries, Inc. shareholders' equity	1,741,656	1,548,696
Noncontrolling interest in consolidated subsidiaries	32,821	22,821
Total shareholders' equity	1,774,477	1,571,517
Total liabilities and shareholders' equity	2,272,908	2,029,602
Eliminations
Current assets:
Investment in subsidiaries and intercompany accounts	(3,533,798)	(3,302,792)
Total assets	(3,533,798)	(3,302,792)
Current liabilities:
Long-term debt, excluding current installments	(544,497)	(514,223)
Shareholders' equity:
Common stock of $1 par value	(712,932)	(712,932)
Additional paid-in capital	(1,184,522)	(1,041,522)
Retained earnings	(1,125,148)	(1,082,896)
Accumulated other comprehensive income (loss)	33,301	48,781
Total Valmont Industries, Inc. shareholders' equity	(2,989,301)	(2,788,569)
Total shareholders' equity	(2,989,301)	(2,788,569)
Total liabilities and shareholders' equity	$ (3,533,798)	$ (3,302,792)