GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 3) - USD ($) $ in Thousands	Dec. 26, 2015	Dec. 27, 2014	Sep. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Current assets:
Cash and cash equivalents	$ 349,074	$ 371,579	$ 371,579	$ 613,706	$ 414,129
Receivables, less allowance of $10,055 in 2015 and $6,672 in 2014	466,443	536,918
Inventories	340,672	359,522
Prepaid expenses	46,137	56,912
Refundable and deferred income taxes	24,526	68,010
Total current assets	1,226,852	1,392,941
Property, plant and equipment, at cost	1,081,056	1,139,569
Less accumulated depreciation and amortization	548,567	533,116
Net property, plant and equipment	532,489	606,453
Goodwill	336,916	385,111		349,632
Other intangible assets	170,197	202,004
Investment in subsidiaries and intercompany accounts	0	0
Other assets, less allowance for doubtful receivables of $10,953 in 2015 and $3,250 in 2014	132,974	143,159
Total assets	2,399,428	2,729,668		2,776,494
Current liabilities:
Current installments of long-term debt	1,077	1,181
Notes payable to banks	976	13,952
Accounts payable	179,983	196,565
Accrued employee compensation and benefits	70,354	87,950
Accrued expenses	105,593	88,480
Dividends payable	8,571	9,086
Total current liabilities	(366,554)	(397,214)
Deferred income taxes	35,669	71,797
Long-term debt, excluding current installments	763,964	766,654
Defined benefit pension liability	179,323	150,124
Deferred compensation	48,417	47,932
Other noncurrent liabilities	40,290	45,542
Shareholders’ equity:
Common stock of $1 par value	27,900	27,900
Additional paid-in capital	0	0
Retained earnings	1,729,679	1,718,662
Accumulated other comprehensive income (loss)	(267,218)	(134,433)
Cost of treasury stock, common shares of 5,042,775 in 2015 and 3,670,781 in 2014	(571,920)	(410,296)
Total Valmont Industries, Inc. shareholders’ equity	918,441	1,201,833
Noncontrolling interest in consolidated subsidiaries	46,770	48,572
Total shareholders’ equity	965,211	1,250,405		1,544,846	1,407,010
Total liabilities and shareholders’ equity	2,399,428	2,729,668
Parent
Current assets:
Cash and cash equivalents	62,281	69,869		215,576	40,926
Receivables, less allowance of $10,055 in 2015 and $6,672 in 2014	130,741	158,316
Inventories	132,222	127,859
Prepaid expenses	9,900	7,087
Refundable and deferred income taxes	24,526	53,307
Total current assets	359,670	416,438
Property, plant and equipment, at cost	541,536	556,658
Less accumulated depreciation and amortization	334,471	319,899
Net property, plant and equipment	207,065	236,759
Goodwill	20,108	20,108
Other intangible assets	238	292
Investment in subsidiaries and intercompany accounts	1,239,228	1,446,989
Other assets, less allowance for doubtful receivables of $10,953 in 2015 and $3,250 in 2014	47,113	46,587
Total assets	1,873,422	2,167,173
Current liabilities:
Current installments of long-term debt	215	213
Notes payable to banks	0	0
Accounts payable	66,723	59,893
Accrued employee compensation and benefits	32,272	48,169
Accrued expenses	31,073	32,616
Dividends payable	8,571	9,086
Total current liabilities	(138,854)	(149,977)
Deferred income taxes	9,686	5,584
Long-term debt, excluding current installments	758,811	759,895
Defined benefit pension liability	0	0
Deferred compensation	43,485	41,803
Other noncurrent liabilities	4,145	8,081
Shareholders’ equity:
Common stock of $1 par value	27,900	27,900
Additional paid-in capital	0	0
Retained earnings	1,729,679	1,718,662
Accumulated other comprehensive income (loss)	(267,218)	(134,433)
Cost of treasury stock, common shares of 5,042,775 in 2015 and 3,670,781 in 2014	(571,920)	(410,296)
Total Valmont Industries, Inc. shareholders’ equity	918,441	1,201,833
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	918,441	1,201,833
Total liabilities and shareholders’ equity	1,873,422	2,167,173
Guarantors
Current assets:
Cash and cash equivalents	4,008	2,157		29,797	6,714
Receivables, less allowance of $10,055 in 2015 and $6,672 in 2014	66,387	68,414
Inventories	38,379	54,914
Prepaid expenses	766	502
Refundable and deferred income taxes	0	6,194
Total current assets	109,540	132,181
Property, plant and equipment, at cost	132,864	124,182
Less accumulated depreciation and amortization	69,956	65,493
Net property, plant and equipment	62,908	58,689
Goodwill	110,562	107,542
Other intangible assets	40,959	43,644
Investment in subsidiaries and intercompany accounts	813,779	825,236
Other assets, less allowance for doubtful receivables of $10,953 in 2015 and $3,250 in 2014	0	0
Total assets	1,137,748	1,167,292
Current liabilities:
Current installments of long-term debt	0	0
Notes payable to banks	0	0
Accounts payable	13,680	15,151
Accrued employee compensation and benefits	6,347	5,385
Accrued expenses	22,802	6,052
Dividends payable	0	0
Total current liabilities	(42,829)	(26,588)
Deferred income taxes	0	28,988
Long-term debt, excluding current installments	0	0
Defined benefit pension liability	0	0
Deferred compensation	0	0
Other noncurrent liabilities	0	0
Shareholders’ equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	159,414	150,286
Retained earnings	541,917	552,676
Accumulated other comprehensive income (loss)	(64,362)	(49,196)
Cost of treasury stock, common shares of 5,042,775 in 2015 and 3,670,781 in 2014	0	0
Total Valmont Industries, Inc. shareholders’ equity	1,094,919	1,111,716
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	1,094,919	1,111,716
Total liabilities and shareholders’ equity	1,137,748	1,167,292
Non- Guarantors
Current assets:
Cash and cash equivalents	282,785	299,553		368,333	366,489
Receivables, less allowance of $10,055 in 2015 and $6,672 in 2014	269,315	310,188
Inventories	173,064	177,512
Prepaid expenses	35,471	49,323
Refundable and deferred income taxes	0	8,509
Total current assets	760,635	845,085
Property, plant and equipment, at cost	406,656	458,729
Less accumulated depreciation and amortization	144,140	147,724
Net property, plant and equipment	262,516	311,005
Goodwill	206,246	257,461
Other intangible assets	129,000	158,068
Investment in subsidiaries and intercompany accounts	939,177	887,055
Other assets, less allowance for doubtful receivables of $10,953 in 2015 and $3,250 in 2014	85,861	96,572
Total assets	2,383,435	2,555,246
Current liabilities:
Current installments of long-term debt	862	968
Notes payable to banks	976	13,952
Accounts payable	99,580	121,521
Accrued employee compensation and benefits	31,735	34,396
Accrued expenses	51,718	49,812
Dividends payable	0	0
Total current liabilities	(184,871)	(220,649)
Deferred income taxes	25,983	37,225
Long-term debt, excluding current installments	5,153	6,759
Defined benefit pension liability	179,323	150,124
Deferred compensation	4,932	6,129
Other noncurrent liabilities	36,145	37,461
Shareholders’ equity:
Common stock of $1 par value	648,683	648,682
Additional paid-in capital	1,107,536	1,098,408
Retained earnings	354,727	397,302
Accumulated other comprehensive income (loss)	(210,688)	(96,065)
Cost of treasury stock, common shares of 5,042,775 in 2015 and 3,670,781 in 2014	0	0
Total Valmont Industries, Inc. shareholders’ equity	1,900,258	2,048,327
Noncontrolling interest in consolidated subsidiaries	46,770	48,572
Total shareholders’ equity	1,947,028	2,096,899
Total liabilities and shareholders’ equity	2,383,435	2,555,246
Eliminations
Current assets:
Cash and cash equivalents	0	0		$ 0	$ 0
Receivables, less allowance of $10,055 in 2015 and $6,672 in 2014	0	0
Inventories	(2,993)	(763)
Prepaid expenses	0	0
Refundable and deferred income taxes	0	0
Total current assets	(2,993)	(763)
Property, plant and equipment, at cost	0	0
Less accumulated depreciation and amortization	0	0
Net property, plant and equipment	0	0
Goodwill	0	0
Other intangible assets	0	0
Investment in subsidiaries and intercompany accounts	(2,992,184)	(3,159,280)
Other assets, less allowance for doubtful receivables of $10,953 in 2015 and $3,250 in 2014	0	0
Total assets	(2,995,177)	(3,160,043)
Current liabilities:
Current installments of long-term debt	0	0
Notes payable to banks	0	0
Accounts payable	0	0
Accrued employee compensation and benefits	0	0
Accrued expenses	0	0
Dividends payable	0	0
Total current liabilities	0	0
Deferred income taxes	0	0
Long-term debt, excluding current installments	0	0
Defined benefit pension liability	0	0
Deferred compensation	0	0
Other noncurrent liabilities	0	0
Shareholders’ equity:
Common stock of $1 par value	(1,106,633)	(1,106,632)
Additional paid-in capital	(1,266,950)	(1,248,694)
Retained earnings	(896,644)	(949,978)
Accumulated other comprehensive income (loss)	275,050	145,261
Cost of treasury stock, common shares of 5,042,775 in 2015 and 3,670,781 in 2014	0	0
Total Valmont Industries, Inc. shareholders’ equity	(2,995,177)	(3,160,043)
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	(2,995,177)	(3,160,043)
Total liabilities and shareholders’ equity	$ (2,995,177)	$ (3,160,043)