The percentage ownership of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

No definition available.

+ Details

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Namespace Prefix:	mtz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

+ Details

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Balance Type:	debit
Period Type:	instant

- 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

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- Definition

The cash inflow associated with the sale and maturity (principal being due) of other investments, prepayment and call (request of early payment) of other investments not otherwise defined in the taxonomy.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

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- Details

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Fair Value of Financial Instruments (Other Investments - Lifeshield) (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Other investment, proceeds		$ 14,705	$ 5,415	$ 23,801
Lifeshield [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Fair value investment, carrying amount					$ 10,000
Fair value investment, ownership percentage					40.00%
Other investment, proceeds	$ 11,000