GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 3) - USD ($) $ in Thousands	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 353,542	$ 313,210
Receivables, less allowance of $9,548 in 2019 and $8,277 in 2018	480,000	483,963
Inventories	374,565	383,566
Contract with Customer, Asset, Net, Current	141,322	112,525
Prepaid expenses, restricted cash, and other assets	32,043	42,800
Refundable income taxes	6,947	4,576
Total current assets	1,388,419	1,340,640
Property, plant and equipment, at cost	1,245,261	1,160,865
Less accumulated depreciation and amortization	687,132	646,873
Net property, plant and equipment	558,129	513,992
Goodwill	428,864	385,207	$ 337,720
Other intangible assets	175,742	175,956
Investment in subsidiaries and intercompany accounts	0	0
Other assets	212,257	114,479
Total assets	2,763,411	2,530,274	2,602,250
Current liabilities:
Current installments of long-term debt	760	779
Notes payable to banks	21,774	10,678
Accounts payable	197,957	218,115
Accrued employee compensation and benefits	83,528	79,291
Accrued expenses	201,681	91,942
Dividends payable	8,079	8,230
Total current liabilities	513,779	409,035
Deferred income taxes	47,955	43,489
Long-term debt, excluding current installments	764,944	741,822
Defined benefit pension liability	140,007	143,904
Other noncurrent liabilities	139,835	56,501
Shareholders’ equity:
Common stock of $1 par value	27,900	27,900
Additional paid-in capital	0	0
Retained earnings	2,140,948	2,027,596
Accumulated other comprehensive income (loss)	(313,422)	(303,185)
Cost of treasury stock, common shares of 6,356,103 in 2019 and 5,951,971 in 2018	(743,942)	(692,549)
Total Valmont Industries, Inc. shareholders’ equity	1,111,484	1,059,762
Noncontrolling interest in consolidated subsidiaries	45,407	75,761
Total shareholders’ equity	1,156,891	1,135,523	$ 1,151,795	$ 982,586
Total liabilities and shareholders’ equity	2,763,411	2,530,274
Eliminations
Current assets:
Cash and cash equivalents	0	0
Receivables, less allowance of $9,548 in 2019 and $8,277 in 2018	0	0
Inventories	(2,757)	(2,402)
Contract with Customer, Asset, Net, Current	0	0
Prepaid expenses, restricted cash, and other assets	0	0
Refundable income taxes	0	0
Total current assets	(2,757)	(2,402)
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	(3,397,876)	(3,381,139)
Other assets	0	0
Total assets	(3,400,633)	(3,383,541)
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	(123,560)	(166,729)
Defined benefit pension liability	0	0
Other noncurrent liabilities	0	0
Shareholders’ equity:
Common stock of $1 par value	(1,106,907)	(1,106,632)
Additional paid-in capital	(1,270,442)	(1,270,442)
Retained earnings	(1,154,585)	(1,092,093)
Accumulated other comprehensive income (loss)	254,861	252,355
Cost of treasury stock, common shares of 6,356,103 in 2019 and 5,951,971 in 2018	0	0
Total Valmont Industries, Inc. shareholders’ equity	(3,277,073)	(3,216,812)
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	(3,277,073)	(3,216,812)
Total liabilities and shareholders’ equity	(3,400,633)	(3,383,541)
Parent
Current assets:
Cash and cash equivalents	182,453	104,256
Receivables, less allowance of $9,548 in 2019 and $8,277 in 2018	134,972	134,943
Inventories	130,686	138,158
Contract with Customer, Asset, Net, Current	65,528	50,271
Prepaid expenses, restricted cash, and other assets	13,820	21,858
Refundable income taxes	6,947	4,576
Total current assets	534,406	454,062
Property, plant and equipment, at cost	635,322	579,046
Less accumulated depreciation and amortization	413,054	390,438
Net property, plant and equipment	222,268	188,608
Goodwill	20,108	20,108
Other intangible assets	763	76
Investment in subsidiaries and intercompany accounts	1,339,206	1,286,545
Other assets	88,549	47,674
Total assets	2,205,300	1,997,073
Current liabilities:
Current installments of long-term debt	0	0
Notes payable to banks	0	0
Accounts payable	68,677	68,304
Accrued employee compensation and benefits	45,294	41,418
Accrued expenses	147,498	25,936
Dividends payable	8,079	8,230
Total current liabilities	269,548	143,888
Deferred income taxes	16,925	14,376
Long-term debt, excluding current installments	734,571	733,964
Defined benefit pension liability	0	0
Other noncurrent liabilities	72,772	45,083
Shareholders’ equity:
Common stock of $1 par value	27,900	27,900
Additional paid-in capital	0	0
Retained earnings	2,140,948	2,027,596
Accumulated other comprehensive income (loss)	(313,422)	(303,185)
Cost of treasury stock, common shares of 6,356,103 in 2019 and 5,951,971 in 2018	(743,942)	(692,549)
Total Valmont Industries, Inc. shareholders’ equity	1,111,484	1,059,762
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	1,111,484	1,059,762
Total liabilities and shareholders’ equity	2,205,300	1,997,073
Guarantors
Current assets:
Cash and cash equivalents	6,169	5,518
Receivables, less allowance of $9,548 in 2019 and $8,277 in 2018	94,090	75,204
Inventories	45,673	37,019
Contract with Customer, Asset, Net, Current	47,402	35,200
Prepaid expenses, restricted cash, and other assets	717	746
Refundable income taxes	0	0
Total current assets	194,051	153,687
Property, plant and equipment, at cost	175,862	172,050
Less accumulated depreciation and amortization	90,384	93,374
Net property, plant and equipment	85,478	78,676
Goodwill	141,581	110,562
Other intangible assets	43,933	27,452
Investment in subsidiaries and intercompany accounts	1,150,458	1,161,612
Other assets	4,323	0
Total assets	1,619,824	1,531,989
Current liabilities:
Current installments of long-term debt	0	0
Notes payable to banks	0	0
Accounts payable	21,464	21,081
Accrued employee compensation and benefits	6,344	7,186
Accrued expenses	11,353	10,132
Dividends payable	0	0
Total current liabilities	39,161	38,399
Deferred income taxes	0	0
Long-term debt, excluding current installments	123,560	166,729
Defined benefit pension liability	0	0
Other noncurrent liabilities	3,168	620
Shareholders’ equity:
Common stock of $1 par value	457,950	457,950
Additional paid-in capital	162,906	162,906
Retained earnings	753,652	624,394
Accumulated other comprehensive income (loss)	79,427	80,991
Cost of treasury stock, common shares of 6,356,103 in 2019 and 5,951,971 in 2018	0	0
Total Valmont Industries, Inc. shareholders’ equity	1,453,935	1,326,241
Noncontrolling interest in consolidated subsidiaries	0	0
Total shareholders’ equity	1,453,935	1,326,241
Total liabilities and shareholders’ equity	1,619,824	1,531,989
Non- Guarantors
Current assets:
Cash and cash equivalents	164,920	203,436
Receivables, less allowance of $9,548 in 2019 and $8,277 in 2018	250,938	273,816
Inventories	200,963	210,791
Contract with Customer, Asset, Net, Current	28,392	27,054
Prepaid expenses, restricted cash, and other assets	17,506	20,196
Refundable income taxes	0	0
Total current assets	662,719	735,293
Property, plant and equipment, at cost	434,077	409,769
Less accumulated depreciation and amortization	183,694	163,061
Net property, plant and equipment	250,383	246,708
Goodwill	267,175	254,537
Other intangible assets	131,046	148,428
Investment in subsidiaries and intercompany accounts	908,212	932,982
Other assets	119,385	66,805
Total assets	2,338,920	2,384,753
Current liabilities:
Current installments of long-term debt	760	779
Notes payable to banks	21,774	10,678
Accounts payable	107,816	128,730
Accrued employee compensation and benefits	31,890	30,687
Accrued expenses	42,830	55,874
Dividends payable	0	0
Total current liabilities	205,070	226,748
Deferred income taxes	31,030	29,113
Long-term debt, excluding current installments	30,373	7,858
Defined benefit pension liability	140,007	143,904
Other noncurrent liabilities	63,895	10,798
Shareholders’ equity:
Common stock of $1 par value	648,957	648,682
Additional paid-in capital	1,107,536	1,107,536
Retained earnings	400,933	467,699
Accumulated other comprehensive income (loss)	(334,288)	(333,346)
Cost of treasury stock, common shares of 6,356,103 in 2019 and 5,951,971 in 2018	0	0
Total Valmont Industries, Inc. shareholders’ equity	1,823,138	1,890,571
Noncontrolling interest in consolidated subsidiaries	45,407	75,761
Total shareholders’ equity	1,868,545	1,966,332
Total liabilities and shareholders’ equity	$ 2,338,920	$ 2,384,753