XML 104 R89.htm IDEA: XBRL DOCUMENT
v3.10.0.1

DERIVATIVE FINANCIAL INSTRUMENTS - Gain (Loss) on Derivatives (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 29, 2018 | Dec. 30, 2017 | Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Derivative, Gain (Loss) on Derivative, Net | $ 993 | $ (74) | $ (74)
Commodity Contract [Member] | Product cost of sales |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Derivative, Gain (Loss) on Derivative, Net | 1,021 | 0 | 0
Foreign Exchange Forward [Member] | Loss from divestiture of grinding media business |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Derivative, Gain (Loss) on Derivative, Net | (1,215) | 0 | 0
Foreign Exchange Forward [Member] | Other income (expense) |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Derivative, Gain (Loss) on Derivative, Net | 782 | 0 | 0
Interest Rate Contract [Member] | Interest expense |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Derivative, Gain (Loss) on Derivative, Net | (423) | (74) | (74)
Cross Currency Interest Rate Contract [Member] | Interest expense |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Derivative, Gain (Loss) on Derivative, Net | $ 828 | $ 0 | $ 0

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeForwardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=vmi_GainLossFromSaleOfBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherNonoperatingIncomeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CrossCurrencyInterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |