XML 102 R83.htm IDEA: XBRL DOCUMENT
v3.3.1.900

DEFINED BENEFIT RETIREMENT PLAN (Details 2) - USD ($) $ in Thousands | Dec. 26, 2015 | Dec. 27, 2014 | Dec. 28, 2013
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | $ 518,126 | $ 542,159 | $ 497,460
Level 2 member |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 518,126 | 542,159 |
Temporary cash investments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 5,181 | 12,320 |
Temporary cash investments | Level 2 member |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 5,181 | 12,320 |
Index linked gilts |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 123,257 | 135,229 |
Index linked gilts | Level 2 member |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 123,257 | 135,229 |
Corporate bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 100,701 | 107,880 |
Corporate bonds | Level 2 member |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 100,701 | 107,880 |
Corporate stock |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 172,456 | 176,010 |
Corporate stock | Level 2 member |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 172,456 | 176,010 |
Diversified growth funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | 116,531 | 110,720 |
Diversified growth funds | Level 2 member |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value pension plans | $ 116,531 | $ 110,720 |

X
- 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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=29635418&loc=d3e12355-114930 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=vmi_TemporaryCashInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=vmi_IndexLinkedGiltsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=vmi_DiversifiedGrowthFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |