GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 4) (USD $) In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 371,579	$ 613,706	$ 414,129	$ 362,894
Receivables, net	536,918	515,440
Inventories	359,522	380,000
Prepaid expenses	56,912	22,997
Refundable and deferred income taxes	68,010	65,697
Total current assets	1,392,941	1,597,840
Property, plant and equipment, at cost	1,139,569	1,017,126
Less accumulated depreciation and amortization	533,116	482,916
Net property, plant and equipment	606,453	534,210
Goodwill	385,111	349,632	330,791
Other intangible assets	202,004	170,917
Other assets	143,159	123,895
Total assets	2,729,668	2,776,494	2,568,551
Current liabilities:
Current installments of long-term debt	1,181	202
Notes payable to banks	13,952	19,024
Accounts payable	196,565	216,121
Accrued employee compensation and benefits	87,950	122,967
Accrued expenses	88,480	71,560
Dividends payable	9,086	6,706
Total current liabilities	397,214	436,580
Deferred income taxes	71,797	78,924
Long-term debt, excluding current installments	766,654	470,907
Defined benefit pension liability	150,124	154,397
Deferred compensation	47,932	39,109
Other noncurrent liabilities	45,542	51,731
Commitments and contingencies
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,718,662	1,562,670
Accumulated other comprehensive income	(134,433)	(47,685)
Treasury stock	(410,296)	(20,860)
Total Valmont Industries, Inc. shareholders' equity	1,201,833	1,522,025
Noncontrolling interest in consolidated subsidiaries	48,572	22,821
Total shareholders' equity	1,250,405	1,544,846	1,407,010	1,197,911
Total liabilities and shareholders' equity	2,729,668	2,776,494
Parent
Current assets:
Cash and cash equivalents	69,869	215,576	40,926	27,545
Receivables, net	158,316	139,179
Inventories	127,859	132,953
Prepaid expenses	7,087	4,735
Refundable and deferred income taxes	53,307	41,167
Total current assets	416,438	533,610
Property, plant and equipment, at cost	556,658	522,734
Less accumulated depreciation and amortization	319,899	300,066
Net property, plant and equipment	236,759	222,668
Goodwill	20,108	20,108
Other intangible assets	292	346
Investment in subsidiaries and intercompany accounts	1,446,989	1,417,425
Other assets	46,587	30,759
Total assets	2,167,173	2,224,916
Current liabilities:
Current installments of long-term debt	213	188
Accounts payable	59,893	62,153
Accrued employee compensation and benefits	48,169	76,370
Accrued expenses	32,616	28,362
Dividends payable	9,086	6,706
Total current liabilities	149,977	173,779
Deferred income taxes	5,584	18,983
Long-term debt, excluding current installments	759,895	470,175
Deferred compensation	41,803	32,339
Other noncurrent liabilities	8,081	7,615
Shareholders' equity:
Common stock of $1 par value	27,900	27,900
Retained earnings	1,718,662	1,562,670
Accumulated other comprehensive income	(134,433)	(47,685)
Treasury stock	(410,296)	(20,860)
Total Valmont Industries, Inc. shareholders' equity	1,201,833	1,522,025
Total shareholders' equity	1,201,833	1,522,025
Total liabilities and shareholders' equity	2,167,173	2,224,916
Guarantors
Current assets:
Cash and cash equivalents	2,157	29,797	6,714	6,883
Receivables, net	68,414	108,600
Inventories	54,914	70,231
Prepaid expenses	502	932
Refundable and deferred income taxes	6,194	8,351
Total current assets	132,181	217,911
Property, plant and equipment, at cost	124,182	125,764
Less accumulated depreciation and amortization	65,493	61,520
Net property, plant and equipment	58,689	64,244
Goodwill	107,542	107,542
Other intangible assets	43,644	48,461
Investment in subsidiaries and intercompany accounts	825,236	791,450
Total assets	1,167,292	1,229,608
Current liabilities:
Accounts payable	15,151	20,365
Accrued employee compensation and benefits	5,385	13,713
Accrued expenses	6,052	7,315
Income taxes payable		19,377
Total current liabilities	26,588	60,770
Deferred income taxes	28,988	29,310
Shareholders' equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	150,286	150,286
Retained earnings	552,676	528,952
Accumulated other comprehensive income	(49,196)	2,340
Total Valmont Industries, Inc. shareholders' equity	1,111,716	1,139,528
Total shareholders' equity	1,111,716	1,139,528
Total liabilities and shareholders' equity	1,167,292	1,229,608
Non-Guarantors
Current assets:
Cash and cash equivalents	299,553	368,333	366,489	328,466
Receivables, net	310,188	267,661
Inventories	177,512	176,816
Prepaid expenses	49,323	17,330
Refundable and deferred income taxes	8,509	16,179
Total current assets	845,085	846,319
Property, plant and equipment, at cost	458,729	368,628
Less accumulated depreciation and amortization	147,724	121,330
Net property, plant and equipment	311,005	247,298
Goodwill	257,461	221,982
Other intangible assets	158,068	122,110
Investment in subsidiaries and intercompany accounts	887,055	827,508
Other assets	96,572	112,513
Total assets	2,555,246	2,377,730
Current liabilities:
Current installments of long-term debt	968	14
Notes payable to banks	13,952	19,024
Accounts payable	121,521	133,603
Accrued employee compensation and benefits	34,396	32,884
Accrued expenses	49,812	35,883
Total current liabilities	220,649	221,408
Deferred income taxes	37,225	30,631
Long-term debt, excluding current installments	6,759	732
Defined benefit pension liability	150,124	154,397
Deferred compensation	6,129	6,770
Other noncurrent liabilities	37,461	44,116
Shareholders' equity:
Common stock of $1 par value	648,682	648,682
Additional paid-in capital	1,098,408	891,236
Retained earnings	397,302	472,162
Accumulated other comprehensive income	(96,065)	(115,225)
Total Valmont Industries, Inc. shareholders' equity	2,048,327	1,896,855
Noncontrolling interest in consolidated subsidiaries	48,572	22,821
Total shareholders' equity	2,096,899	1,919,676
Total liabilities and shareholders' equity	2,555,246	2,377,730
Eliminations
Current assets:
Inventories	(763)
Total current assets	(763)
Investment in subsidiaries and intercompany accounts	(3,159,280)	(3,036,383)
Other assets		(19,377)
Total assets	(3,160,043)	(3,055,760)
Current liabilities:
Income taxes payable		(19,377)
Total current liabilities		(19,377)
Shareholders' equity:
Common stock of $1 par value	(1,106,633)	(1,106,632)
Additional paid-in capital	(1,248,694)	(1,041,522)
Retained earnings	(949,978)	(1,001,114)
Accumulated other comprehensive income	145,261	112,885
Total Valmont Industries, Inc. shareholders' equity	(3,160,043)	(3,036,353)
Total shareholders' equity	(3,160,043)	(3,036,353)
Total liabilities and shareholders' equity	$ (3,160,043)	$ (3,055,760)