GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION - Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 26, 2016	Dec. 26, 2015	Mar. 28, 2015	Dec. 27, 2014
Current assets:
Cash and cash equivalents	$ 387,714	$ 349,074	$ 318,366	$ 371,579
Receivables, net	449,379	466,443
Inventories	350,768	340,672
Prepaid expenses	46,080	46,137
Refundable income taxes	18,897	24,526
Total current assets	1,252,838	1,226,852
Property, plant and equipment, at cost	1,100,804	1,081,056
Less accumulated depreciation and amortization	568,297	548,567
Net property, plant and equipment	532,507	532,489
Goodwill	334,269	336,916
Other intangible assets	164,537	170,197
Investment in subsidiaries and intercompany accounts	0	0
Other assets	115,711	125,928
Total assets	2,399,862	2,392,382
Current liabilities:
Current installments of long-term debt	1,110	1,077
Notes payable to banks	2,402	976
Accounts payable	183,059	179,983
Accrued employee compensation and benefits	58,002	70,354
Accrued expenses	111,477	105,593
Dividends payable	8,527	8,571
Total current liabilities	(364,577)	(366,554)
Deferred income taxes	39,644	35,669
Long-term debt, excluding current installments	756,878	756,918
Defined benefit pension liability	170,203	179,323
Deferred compensation	48,456	48,417
Other noncurrent liabilities	39,953	40,290
Shareholders’ equity:
Common stock of $1 par value	27,900	27,900
Additional paid-in capital	0	0
Retained earnings	1,756,082	1,729,679
Accumulated other comprehensive income (loss)	(265,811)	(267,218)
Treasury stock	(587,117)	(571,920)
Total Valmont Industries, Inc. shareholders’ equity	931,054	918,441
Noncontrolling interest in consolidated subsidiaries	49,097	46,770
Total shareholders’ equity	980,151	965,211	1,143,864	1,250,405
Total liabilities and shareholders’ equity	2,399,862	2,392,382
Parent
Current assets:
Cash and cash equivalents	76,634	62,281	25,571	69,869
Receivables, net	128,713	130,741
Inventories	138,589	132,222
Prepaid expenses	5,435	9,900
Refundable income taxes	18,897	24,526
Total current assets	368,268	359,670
Property, plant and equipment, at cost	537,701	541,536
Less accumulated depreciation and amortization	338,782	334,471
Net property, plant and equipment	198,919	207,065
Goodwill	20,108	20,108
Other intangible assets	225	238
Investment in subsidiaries and intercompany accounts	1,250,625	1,239,228
Other assets	39,645	40,067
Total assets	1,877,790	1,866,376
Current liabilities:
Current installments of long-term debt	215	215
Notes payable to banks	0	0
Accounts payable	58,622	66,723
Accrued employee compensation and benefits	21,357	32,272
Accrued expenses	42,241	31,073
Dividends payable	8,527	8,571
Total current liabilities	(130,962)	(138,854)
Deferred income taxes	15,874	9,686
Long-term debt, excluding current installments	751,541	751,765
Defined benefit pension liability	0	0
Deferred compensation	43,338	43,485
Other noncurrent liabilities	5,021	4,145
Shareholders’ equity:
Common stock of $1 par value	27,900	27,900
Additional paid-in capital	0	0
Retained earnings	1,756,082	1,729,679
Accumulated other comprehensive income (loss)	(265,811)	(267,218)
Treasury stock	(587,117)	(571,920)
Total Valmont Industries, Inc. shareholders’ equity	931,054	918,441
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	931,054	918,441
Total liabilities and shareholders’ equity	1,877,790	1,866,376
Guarantors
Current assets:
Cash and cash equivalents	4,566	4,008	1,367	2,157
Receivables, net	54,384	66,387
Inventories	40,782	38,379
Prepaid expenses	804	766
Refundable income taxes	0	0
Total current assets	100,536	109,540
Property, plant and equipment, at cost	142,955	132,864
Less accumulated depreciation and amortization	74,063	69,956
Net property, plant and equipment	68,892	62,908
Goodwill	110,562	110,562
Other intangible assets	39,710	40,959
Investment in subsidiaries and intercompany accounts	837,066	813,779
Other assets	0	0
Total assets	1,156,766	1,137,748
Current liabilities:
Current installments of long-term debt	0	0
Notes payable to banks	0	0
Accounts payable	14,148	13,680
Accrued employee compensation and benefits	4,665	6,347
Accrued expenses	16,752	22,802
Dividends payable	0	0
Total current liabilities	(35,565)	(42,829)
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	457,950	457,950
Additional paid-in capital	159,414	159,414
Retained earnings	568,377	541,917
Accumulated other comprehensive income (loss)	(64,540)	(64,362)
Treasury stock	0	0
Total Valmont Industries, Inc. shareholders’ equity	1,121,201	1,094,919
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	1,121,201	1,094,919
Total liabilities and shareholders’ equity	1,156,766	1,137,748
Non- Guarantors
Current assets:
Cash and cash equivalents	306,514	282,785	291,428	299,553
Receivables, net	266,282	269,315
Inventories	174,983	173,064
Prepaid expenses	39,841	35,471
Refundable income taxes	0	0
Total current assets	787,620	760,635
Property, plant and equipment, at cost	420,148	406,656
Less accumulated depreciation and amortization	155,452	144,140
Net property, plant and equipment	264,696	262,516
Goodwill	203,599	206,246
Other intangible assets	124,602	129,000
Investment in subsidiaries and intercompany accounts	1,096,458	939,177
Other assets	76,066	85,861
Total assets	2,553,041	2,383,435
Current liabilities:
Current installments of long-term debt	895	862
Notes payable to banks	2,402	976
Accounts payable	110,289	99,580
Accrued employee compensation and benefits	31,980	31,735
Accrued expenses	52,484	51,718
Dividends payable	0	0
Total current liabilities	(198,050)	(184,871)
Deferred income taxes	23,770	25,983
Long-term debt, excluding current installments	5,337	5,153
Defined benefit pension liability	170,203	179,323
Deferred compensation	5,118	4,932
Other noncurrent liabilities	34,932	36,145
Shareholders’ equity:
Common stock of $1 par value	648,682	648,683
Additional paid-in capital	1,107,536	1,107,536
Retained earnings	513,246	354,727
Accumulated other comprehensive income (loss)	(202,930)	(210,688)
Treasury stock	0	0
Total Valmont Industries, Inc. shareholders’ equity	2,066,534	1,900,258
Noncontrolling interest in consolidated subsidiaries	49,097	46,770
Total shareholders’ equity	2,115,631	1,947,028
Total liabilities and shareholders’ equity	2,553,041	2,383,435
Eliminations
Current assets:
Cash and cash equivalents	0	0	$ 0	$ 0
Receivables, net	0	0
Inventories	(3,586)	(2,993)
Prepaid expenses	0	0
Refundable income taxes	0	0
Total current assets	(3,586)	(2,993)
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	(3,184,149)	(2,992,184)
Other assets	0	0
Total assets	(3,187,735)	(2,995,177)
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	(1,106,632)	(1,106,633)
Additional paid-in capital	(1,266,950)	(1,266,950)
Retained earnings	(1,081,623)	(896,644)
Accumulated other comprehensive income (loss)	267,470	275,050
Treasury stock	0	0
Total Valmont Industries, Inc. shareholders’ equity	(3,187,735)	(2,995,177)
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	(3,187,735)	(2,995,177)
Total liabilities and shareholders’ equity	$ (3,187,735)	$ (2,995,177)