XML 60 R46.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Commitments and Contingencies - Additional Information (Details) |  | 1 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Jul. 13, 2018 USD ($) | Jan. 31, 2018 USD ($) unilateral_administrative_orders | Sep. 29, 2018 USD ($) property Import_entry | Sep. 29, 2018 potentially_responsible_party | Sep. 29, 2018 smelter_site | Nov. 08, 2016 USD ($) | Apr. 19, 2010
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Term of guarantees |  |  | 1 year |  |  |  |
Payments required to be made under guarantees, maximum |  |  | $ 8,500,000 |  |  |  |
United States Department of Commerce Antidumping Review [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Assignment of antidumping duty rate on U.S. imports by Company subsidiaries |  |  |  |  |  |  | 48.33%
Payment for interest and duties |  |  | $ 3,000,000 |  |  |  |
Number of import entries | Import_entry |  |  | 795 |  |  |  |
Unlawful Employment Practices [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Term of consent decree |  |  | 2 years 6 months |  |  |  |
Maximum amount to be paid to fund discrimination claims | $ 1,000,000.0 |  |  |  |  |  |
Southeast Kansas Sites [Member] | Non operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Number of parties involved in settlement negotiations |  |  |  | 2 | 3 |  |
Environmental reserves |  |  | $ 5,600,000 |  |  |  |
Shasta Area Mine Sites [Member] | Non operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Period of permit, implementation of Best Management Practices |  |  | 10 years |  |  |  |
Estimated remediation costs, term |  |  | 30 years |  |  |  |
Lead Refinery Site [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Financial guarantee |  |  |  |  |  | $ 1,000,000 |
Lead Refinery Site [Member] | Non operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs, term |  |  | 19 years |  |  |  |
Amount 2 other PRPs will pay to fund cleanup |  |  | $ 26,000,000 |  |  |  |
Number of surrounding properties | property |  |  | 300 |  |  |  |
Lead Refinery NPL Site [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Environmental reserves |  | $ 4,500,000 |  |  |  |  |
Number of UAOs | unilateral_administrative_orders |  | 2 |  |  |  |  |
Site contingency, total costs |  | $ 25,000,000 |  |  |  |  |
Site contingency, amount agreed upon to pay PRPs for past costs |  | $ 2,000,000 |  |  |  |  |
Mueller Copper Tube Products, Inc. [Member] | Operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs, term |  |  | 8 years |  |  |  |
Minimum [Member] | Shasta Area Mine Sites [Member] | Non operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs |  |  | $ 12,800,000 |  |  |  |
Minimum [Member] | Lead Refinery Site [Member] | Non operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs |  |  | 1,800,000 |  |  |  |
Minimum [Member] | Mueller Copper Tube Products, Inc. [Member] | Operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs |  |  | 800,000 |  |  |  |
Maximum [Member] | Shasta Area Mine Sites [Member] | Non operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs |  |  | 17,600,000 |  |  |  |
Maximum [Member] | Lead Refinery Site [Member] | Non operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs |  |  | 3,000,000 |  |  |  |
Maximum [Member] | Mueller Copper Tube Products, Inc. [Member] | Operating Properties [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Estimated remediation costs |  |  | $ 1,200,000 |  |  |  |

X
- Definition Antidumping fees imposed on certain subsidiaries of the entity. + References No definition available. + Details
Name: | mli_AssignmentOfAntidumpingDutyRateOnUSImportsByCompanySubsidiaries
Namespace Prefix: | mli_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Refers to import entries made during the period. + References No definition available. + Details
Name: | mli_NumberOfImportEntries
Namespace Prefix: | mli_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of parties involved in settlement negotiations. + References No definition available. + Details
Name: | mli_NumberOfPartiesInvolvedInSettlementNegotiations
Namespace Prefix: | mli_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of properties surrounding the Lead Refinery site. + References No definition available. + Details
Name: | mli_NumberOfSurroundingProperties
Namespace Prefix: | mli_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Refers to requesting payment for interest and duties related to import entries. + References No definition available. + Details
Name: | mli_PaymentForInterestAndDuties
Namespace Prefix: | mli_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The period of permit for the continued implementation of Best Management Practices. + References No definition available. + Details
Name: | mli_PeriodOfPermitImplementationOfBestManagementPractices
Namespace Prefix: | mli_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Site Contingency, Environmental Remedial and Feasibility Study, Financial Guarantee + References No definition available. + Details
Name: | mli_SiteContingencyEnvironmentalRemedialandFeasibilityStudyFinancialGuarantee
Namespace Prefix: | mli_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Estimated time frame for resolution of the uncertainty as to the loss for an individual site. + References No definition available. + Details
Name: | mli_SiteContingencyEstimatedTimeFrameToResolveContingency1
Namespace Prefix: | mli_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Site Contingency, Number Of Unilateral Administrative Orders + References No definition available. + Details
Name: | mli_SiteContingencyNumberOfUnilateralAdministrativeOrders
Namespace Prefix: | mli_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Best estimate of the properties loss exposure around the refinery site, for reasonably possible environmental contingencies for which no accrual has been recorded. + References No definition available. + Details
Name: | mli_SiteContingencyPropertiesLossExposureNotAccruedBestEstimate
Namespace Prefix: | mli_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Site Contingency, Reimbursement Costs To Third Parties For Past Costs + References No definition available. + Details
Name: | mli_SiteContingencyReimbursementCostsToThirdPartiesForPastCosts
Namespace Prefix: | mli_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Site Contingency, Total Cost For All Parties, Best Estimate + References No definition available. + Details
Name: | mli_SiteContingencyTotalCostForAllPartiesBestEstimate
Namespace Prefix: | mli_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Term Of Consent Decree + References No definition available. + Details
Name: | mli_TermOfConsentDecree
Namespace Prefix: | mli_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the term of guarantees. + References No definition available. + Details
Name: | mli_TermOfGuarantees
Namespace Prefix: | mli_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 + Details
Name: | us-gaap_AccrualForEnvironmentalLossContingencies
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Estimate of reasonably possible loss exposure in excess of amount accrued for remediation, site restoration, postclosure, monitoring commitments, or other exit costs associated with the sale, disposal or abandonment of a particular property resulting from unanticipated contamination of the assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 5.Y.Q4) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14394-108349 + Details
Name: | us-gaap_EnvironmentalExitCostsReasonablyPossibleAdditionalLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Amount of damages awarded to the plaintiff in the legal matter. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349 + Details
Name: | us-gaap_LossContingencyDamagesAwardedValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_UnfavorableRegulatoryActionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=mli_UnlawfulEmploymentPracticesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationSiteAxis=mli_SoutheastKansasSitesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LeaseArrangementTypeAxis=mli_NonOperatingPropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationSiteAxis=mli_ShastaAreaMineSitesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationSiteAxis=mli_LeadRefinerySiteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationSiteAxis=mli_LeadRefineryNPLSiteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationSiteAxis=mli_MuellerCopperTubeProductsIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LeaseArrangementTypeAxis=mli_OperatingPropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |