XML 69 R60.htm IDEA: XBRL DOCUMENT
v3.23.2

Commitments and Contingencies (Details) $ in Thousands |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Apr. 25, 2023 USD ($) | May 04, 2021 USD ($) | Dec. 31, 2019 USD ($) weld | Jun. 30, 2023 USD ($) | Jun. 30, 2022 USD ($) | Mar. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Jun. 30, 2023 USD ($) claim | Jun. 30, 2022 USD ($) | Dec. 31, 2022 USD ($) | Jan. 01, 2020 USD ($)
Litigation |  |  |  |  |  |  |  |  |  |  |
Accounts receivable, net |  |  |  | $ 118,773 |  |  |  | $ 118,773 |  | $ 123,657 |
Contingency charges |  |  |  | 150 | $ (153) |  |  | 150 | $ (994) |  |
Reserve for past due receivables |  |  |  | 1,861 |  |  |  | 1,861 |  | 4,110 |
Pension accrual |  |  |  | 2,458 |  |  |  | 2,458 |  | 2,519 |
Texas Customer |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Accounts receivable, net |  |  | $ 1,400 |  |  |  |  |  |  |  |
Amount of damages claimed |  |  | 1,400 |  |  |  |  |  |  |  |
Litigation and Commercial Claims | Various Pipeline Projects for Texas Customer |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Amount of damages claimed |  |  | $ 7,600 |  |  |  |  |  |  |  |
Litigation and Commercial Claims | Texas Customer | Various Pipeline Projects for Texas Customer |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Accounts receivable, net |  |  |  | 1,400 |  |  |  | $ 1,400 |  |  |
Number or welds not in compliance | weld |  |  | 66 |  |  |  |  |  |  |  |
Number of welds inspected (over) | weld |  |  | 16,000 |  |  |  |  |  |  |  |
Amount of damages claimed |  |  | $ 1,400 |  |  |  |  |  |  |  |
Amount awarded to other party | $ 300 |  |  |  |  |  |  |  |  |  |
Release of claim on receivables | $ 1,400 |  |  |  |  |  |  |  |  |  |
Contingency charges |  |  |  |  |  |  |  |  |  | $ 100 |
Reserve for past due receivables |  |  | $ 1,400 |  |  |  |  |  |  |  |
Class Action |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Amount awarded to other party |  | $ 2,300 |  |  |  |  |  |  |  |  |
Contingency charges |  |  |  |  |  | $ 1,600 | $ 800 |  |  |  |
Number of proceedings | claim |  |  |  |  |  |  |  | 2 |  |  |
Class Action on Behalf of Employees |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Number of proceedings | claim |  |  |  |  |  |  |  | 1 |  |  |
Class Action on Behalf of State of California |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Number of proceedings | claim |  |  |  |  |  |  |  | 1 |  |  |
Pension Related Contingencies |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Pension accrual |  |  |  | 2,500 |  |  |  | $ 2,500 |  |  |
Severance and Labor Disputes | Foreign Subsidiary | Right to Customer Contracts | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Germany |  |  |  |  |  |  |  |  |  |  |
Litigation |  |  |  |  |  |  |  |  |  |  |
Contingency charges |  |  |  |  |  |  |  | 100 |  |  |
Consideration received on sale of subsidiary |  |  |  |  |  |  |  |  |  |  | $ 100
Settlement liability |  |  |  | $ 200 |  |  |  | 200 |  |  |
Payments of severance obligations |  |  |  |  |  |  |  | 400 |  |  |
Reversal of severance obligations |  |  |  |  |  |  |  | $ 1,000 |  |  |

X
- Definition Litigation Settlement, Release Of Claim + References No definition available. + Details
Name: | mg_LitigationSettlementReleaseOfClaim
Namespace Prefix: | mg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Loss Contingency Accrual, Reversals + References No definition available. + Details
Name: | mg_LossContingencyAccrualReversals
Namespace Prefix: | mg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Loss Contingency, Number Of Welds Alleged Not In Compliance + References No definition available. + Details
Name: | mg_LossContingencyNumberOfWeldsAllegedNotInCompliance
Namespace Prefix: | mg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Loss Contingency, Number Of Welds Inspected + References No definition available. + Details
Name: | mg_LossContingencyNumberOfWeldsInspected
Namespace Prefix: | mg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of allowance for credit loss on accounts receivable, classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-4 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation. + References No definition available. + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount awarded to other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedToOtherParty
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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482425/460-10-50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-4 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-4 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-9 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-9 + Details
Name: | us-gaap_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of loss contingency liability. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-1 Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-10 + Details
Name: | us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of cash outflow reducing loss contingency liability. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-1 + Details
Name: | us-gaap_LossContingencyAccrualPayments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The value (monetary amount) of the award the plaintiff seeks in the legal matter. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-9 + Details
Name: | us-gaap_LossContingencyDamagesSoughtValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-1 + Details
Name: | us-gaap_LossContingencyLossInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total number of new claims filed pertaining to a loss contingency during the period. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-4 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-9 + Details
Name: | us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the obligation recognized by withdrawing from a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References No definition available. + Details
Name: | us-gaap_MultiemployerPlansWithdrawalObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 852 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481372/852-10-55-10 + Details
Name: | us-gaap_ReceivablesNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_MajorCustomersAxis=mg_TexasCustomerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_LitigationCaseAxis=mg_VariousPipelineProjectsForTexasCustomerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=mg_RightToCustomerContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_DE
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |