Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Aug. 02, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-08106
Entity Registrant Name	MasTec, Inc.
Entity Incorporation, State or Country Code	FL
Entity Tax Identification Number	65-0829355
Entity Address, Address Line One	800 S. Douglas Road, 12th Floor
Entity Address, City or Town	Coral Gables,
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33134
City Area Code	305
Local Phone Number	599-1800
Title of 12(b) Security	Common Stock, $0.10 Par Value
Trading Symbol	MTZ
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		74,314,887
Entity Central Index Key	0000015615
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false