XML 89 R77.htm IDEA: XBRL DOCUMENT
v3.21.2

Commitments and Contingencies - Letters of Credit, Bonds, Self-Insurance - Narrative (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Commitments and Contingencies [Line Items] |  |
Letters of credit issued | $ 134.9 | $ 151.8
Self-Insurance | Workers' Compensation, General and Automobile Policies |  |
Commitments and Contingencies [Line Items] |  |
Self-insurance reserve | 153.6 | 129.6
Self-Insurance | Workers' Compensation, General and Automobile Policies | Other Long-Term Liabilities |  |
Commitments and Contingencies [Line Items] |  |
Self-insurance reserve, non-current | 98.7 | 86.1
Self-Insurance | Employee Group Medical Claims |  |
Commitments and Contingencies [Line Items] |  |
Self-insurance reserve | 4.7 | 4.3
Performance and Payment Bonds |  |
Commitments and Contingencies [Line Items] |  |
Bonded projects, estimated costs to complete | 569.6 | 263.2
Performance and Payment Bonds | Subsidiaries |  |
Commitments and Contingencies [Line Items] |  |
Outstanding bonds, amount | 1,723.9 | 764.8
Performance and Payment Bonds | Subsidiaries | Corporate Joint Venture |  |
Commitments and Contingencies [Line Items] |  |
Outstanding bonds, amount | 115.0 |
Financial Guarantees | Self-Insurance | Workers' Compensation, General and Automobile Policies |  |
Commitments and Contingencies [Line Items] |  |
Letters of credit issued | 64.1 | 59.3
Surety Bonds | Self-Insurance | Workers' Compensation |  |
Commitments and Contingencies [Line Items] |  |
Outstanding bonds, amount | $ 39.0 | $ 37.4

X
- Definition Reflects the amount of estimated costs to complete projects that are secured by outstanding performance and/or payment bonds as of the balance sheet date. + References No definition available. + Details
Name: | mtz_EstimatedCostsToCompleteProjectsSecuredByBonds
Namespace Prefix: | mtz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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=124440162&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
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 Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_SelfInsuranceReserve
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying amount of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property that are expected to be paid after one year (or the normal operating cycle, if longer). + References No definition available. + Details
Name: | us-gaap_SelfInsuranceReserveNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_PropertyLiabilityAndCasualtyInsuranceSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_GroupPoliciesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_PerformanceGuaranteeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_SubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_FinancialStandbyLetterOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_SuretyBondMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_AccidentAndHealthInsuranceSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |