Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482130/360-10-45-5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Indicates line item in statement of income that includes gain (loss) recognized on sale or disposal of disposal group. Excludes discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-3

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the cash inflow during the period from the sale of a component of the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The additional proceeds to be received, from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

No definition available.

+ Details

Name:	vmi_DivestitureOfBusinessesAdditionalProceedsToBeReceived
Namespace Prefix:	vmi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of installments for the additional proceeds to be received, from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

No definition available.

+ Details

Name:	vmi_DivestitureOfBusinessesAdditionalProceedsToBeReceivedNumberOfInstallments
Namespace Prefix:	vmi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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DIVESTITURES (Details) $ in Thousands, $ in Thousands				3 Months Ended
DIVESTITURES (Details) $ in Thousands, $ in Thousands	Nov. 05, 2024 USD ($)	Oct. 31, 2024 USD ($) payment	Oct. 31, 2024 AUD ($) payment	Dec. 28, 2024 USD ($)	Dec. 28, 2024 AUD ($)
George Industries
DIVESTITURES
Proceeds from divestiture, net of cash divested	$ 500
Pre-tax gain (loss) on sale of engineering and equipment				$ 2,779
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]				Nonoperating Income (Expense)	Nonoperating Income (Expense)
Extractive Business
DIVESTITURES
Proceeds from divestiture, net of cash divested		$ 3,330	$ 5,042
Pre-tax gain (loss) on sale of engineering and equipment				$ 1,695	$ 2,567
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]				Nonoperating Income (Expense)	Nonoperating Income (Expense)
Divestiture of businesses, additional proceeds to be received		$ 1,172	$ 1,800
Number of Installments \| payment		2	2