Negative equity method investment, presented as a liability

No definition available.

Name:	mtz_EquityMethodInvestmentNegativeAmount
Namespace Prefix:	mtz_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Noncontrolling Interest, Percentage of Voting Interests Acquired

+ References

No definition available.

+ Details

Name:	mtz_NoncontrollingInterestPercentageOfVotingInterestsAcquired
Namespace Prefix:	mtz_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(3))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 5: 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(3)(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_AccountsReceivableRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

- Definition

Amount of cash inflow (outflow) from (to) a noncontrolling interest. Excludes dividends paid to the noncontrolling interest.

+ References

No definition available.

+ Details

Name:	us-gaap_ProceedsFromPaymentsToMinorityShareholders
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

- Definition

Reflects the sum of all other revenue and income realized from sales and other transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=mtz_SubcontractingArrangementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_ManagementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mtz_A2020AcquisitionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=mtz_CommunityCondotteDeMoyaJVLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions - Management/Subcontracting agreement - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jun. 30, 2020
Related Party Transaction [Line Items]
Line of credit facility, letters of credit issued		$ 134,900		$ 134,900		$ 151,800
Noncontrolling interest, percentage of voting interests acquired	15.00%
Payments to non-controlling interests, including acquisition of interests and distributions	$ 6,800			8,965	$ 719
Subcontracting Arrangements \| Management \| Line of Credit
Related Party Transaction [Line Items]
Line of credit facility, letters of credit issued		15,000		15,000
Subcontracting Arrangements \| Management \| 2020 Acquisitions
Related Party Transaction [Line Items]
Receivables, net, related party		200		200		400
Charges, related party		200	$ 600	600	$ 600
Community Condotte DeMoya JV, LLC
Related Party Transaction [Line Items]
Equity method investments, ownership percentage							25.00%
Negative equity method investment		1,600		1,600		2,000
Community Condotte DeMoya JV, LLC \| Subcontracting Arrangements \| Management
Related Party Transaction [Line Items]
Receivables, net, related party		$ 2,300		$ 2,300		$ 1,900