EMPLOYEE RETIREMENT SAVINGS PLAN (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
EMPLOYEE RETIREMENT SAVINGS PLAN
Employee contribution limit per calendar year to 401 (k) plan	50.00%
Company contributions	$ 11,600	$ 10,000	$ 8,700
Assets related to non-qualified deferred compensation plan included in other assets	27,133	20,087
Liabilities related to non-qualified deferred compensation plan included in other noncurrent liabilities	27,133	20,087
Total amount distributed from non-qualified deferred compensation plan	$ 1,626	$ 250

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

The amount of distributions made to the individual during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualDistributionsPaid
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

+ Details

Name:	us-gaap_DeferredCompensationPlanAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

+ Details

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

- Definition

Carrying value as of the balance sheet date of liabilities for fully funded, non-qualified deferred compensation plan payable beyond one year (or the operating cycle, if longer).

+ References

No definition available.

+ Details

Name:	vmi_DeferredCompensationLiabilitiesNoncurrent
Namespace Prefix:	vmi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The limit of annual employee contributions to the plan per calendar year as a percentage of compensation.

+ References

No definition available.

+ Details

Name:	vmi_DefinedContributionPlanEmployeeContributionLimitPercentageOfCompensation
Namespace Prefix:	vmi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration