GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 5) (USD $) In Thousands, unless otherwise specified	Sep. 27, 2014	Dec. 28, 2013	Sep. 28, 2013	Dec. 29, 2012
Current assets:
Cash and cash equivalents	$ 452,218	$ 613,706	$ 543,369	$ 414,129
Receivables, net	570,810	515,440
Inventories	384,645	380,000
Prepaid expenses	64,673	22,997
Refundable and deferred income taxes	64,438	65,697
Total current assets	1,536,784	1,597,840
Property, plant and equipment, at cost	1,138,421	1,017,126
Less accumulated depreciation and amortization	521,869	482,916
Net property, plant and equipment	616,552	534,210
Goodwill	374,144	349,632
Other intangible assets	199,819	170,917
Other assets	135,422	123,895
Total assets	2,862,721	2,776,494
Current liabilities:
Current installments of long-term debt	188	202
Notes payable to banks	17,863	19,024
Accounts payable	209,996	216,121
Accrued employee compensation and benefits	94,459	122,967
Accrued expenses	93,483	71,560
Dividends payable	9,299	6,706
Total current liabilities	425,288	436,580
Deferred income taxes	76,607	78,924
Long-term debt, excluding current installments	768,611	470,907
Defined benefit pension liability	136,808	154,397
Deferred compensation	48,014	39,109
Other noncurrent liabilities	48,707	51,731
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,687,536	1,562,670
Accumulated other comprehensive income (loss)	(72,071)	(47,685)
Treasury stock	(333,744)	(20,860)
Total Valmont Industries, Inc. shareholders' equity	1,309,621	1,522,025
Noncontrolling interest in consolidated subsidiaries	49,065	22,821
Total shareholders' equity	1,358,686	1,544,846	1,575,785	1,407,010
Total liabilities and shareholders' equity	2,862,721	2,776,494
Parent
Current assets:
Cash and cash equivalents	153,921	215,576	158,360	40,926
Receivables, net	158,080	139,179
Inventories	130,039	132,953
Prepaid expenses	6,948	4,735
Refundable and deferred income taxes	46,233	41,167
Total current assets	495,221	533,610
Property, plant and equipment, at cost	555,552	522,734
Less accumulated depreciation and amortization	316,637	300,066
Net property, plant and equipment	238,915	222,668
Goodwill	20,108	20,108
Other intangible assets	306	346
Investment in subsidiaries and intercompany accounts	1,477,670	1,417,425
Other assets	44,958	30,759
Total assets	2,277,178	2,224,916
Current liabilities:
Current installments of long-term debt	188	188
Accounts payable	59,365	62,153
Accrued employee compensation and benefits	49,004	76,370
Accrued expenses	35,806	28,362
Dividends payable	9,299	6,706
Total current liabilities	153,662	173,779
Deferred income taxes	2,575	18,983
Long-term debt, excluding current installments	760,130	470,175
Deferred compensation	41,629	32,339
Other noncurrent liabilities	9,561	7,615
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,687,536	1,562,670
Accumulated other comprehensive income (loss)	(72,071)	(47,685)
Treasury stock	(333,744)	(20,860)
Total Valmont Industries, Inc. shareholders' equity	1,309,621	1,522,025
Total shareholders' equity	1,309,621	1,522,025
Total liabilities and shareholders' equity	2,277,178	2,224,916
Guarantors
Current assets:
Cash and cash equivalents	3,663	49,053	51,186	83,203
Receivables, net	78,808	108,646
Inventories	65,194	70,231
Prepaid expenses	759	932
Refundable and deferred income taxes	6,396	8,351
Total current assets	154,820	237,213
Property, plant and equipment, at cost	126,438	125,764
Less accumulated depreciation and amortization	66,509	61,520
Net property, plant and equipment	59,929	64,244
Goodwill	107,542	107,542
Other intangible assets	44,847	48,461
Investment in subsidiaries and intercompany accounts	1,489,054	1,367,308
Total assets	1,856,192	1,824,768
Current liabilities:
Accounts payable	16,720	20,365
Accrued employee compensation and benefits	5,508	13,713
Accrued expenses	6,223	7,315
Total current liabilities	28,451	41,393
Deferred income taxes	28,649	29,279
Long-term debt, excluding current installments	507,362	514,223
Shareholders' equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	150,286	150,286
Retained earnings	608,558	565,193
Accumulated other comprehensive income (loss)	74,936	66,444
Total Valmont Industries, Inc. shareholders' equity	1,291,730	1,239,873
Total shareholders' equity	1,291,730	1,239,873
Total liabilities and shareholders' equity	1,856,192	1,824,768
Non-Guarantors
Current assets:
Cash and cash equivalents	294,634	349,077	333,823	290,000
Receivables, net	333,922	267,615
Inventories	189,412	176,816
Prepaid expenses	56,966	17,330
Refundable and deferred income taxes	11,809	16,179
Total current assets	886,743	827,017
Property, plant and equipment, at cost	456,431	368,628
Less accumulated depreciation and amortization	138,723	121,330
Net property, plant and equipment	317,708	247,298
Goodwill	246,494	221,982
Other intangible assets	154,666	122,110
Investment in subsidiaries and intercompany accounts	564,888	518,059
Other assets	90,464	93,136
Total assets	2,260,963	2,029,602
Current liabilities:
Current installments of long-term debt		14
Notes payable to banks	17,863	19,024
Accounts payable	133,911	133,603
Accrued employee compensation and benefits	39,947	32,884
Accrued expenses	51,454	35,883
Total current liabilities	243,175	221,408
Deferred income taxes	45,383	30,662
Long-term debt, excluding current installments	8,481	732
Defined benefit pension liability	136,808	154,397
Deferred compensation	6,385	6,770
Other noncurrent liabilities	39,146	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	505,735	517,703
Accumulated other comprehensive income (loss)	(62,433)	(115,225)
Total Valmont Industries, Inc. shareholders' equity	1,732,520	1,548,696
Noncontrolling interest in consolidated subsidiaries	49,065	22,821
Total shareholders' equity	1,781,585	1,571,517
Total liabilities and shareholders' equity	2,260,963	2,029,602
Eliminations
Current assets:
Investment in subsidiaries and intercompany accounts	(3,531,612)	(3,302,792)
Total assets	(3,531,612)	(3,302,792)
Current liabilities:
Long-term debt, excluding current installments	(507,362)	(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	(1,114,293)	(1,082,896)
Accumulated other comprehensive income (loss)	(12,503)	48,781
Total Valmont Industries, Inc. shareholders' equity	(3,024,250)	(2,788,569)
Total shareholders' equity	(3,024,250)	(2,788,569)
Total liabilities and shareholders' equity	$ (3,531,612)	$ (3,302,792)