Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
6 Months Ended
Jun. 30, 2020
Aug. 04, 2020
Document And Entity Information [Abstract]    
Document Type 10-Q  
Document Fiscal Period Focus Q2  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2020  
Document Transition Report false  
Amendment Flag false  
Document Fiscal Year Focus 2020  
Current Fiscal Year End Date --12-31  
Entity File Number 001-13831  
Entity Registrant Name Quanta Services, Inc.  
Entity Central Index Key 0001050915  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 74-2851603  
Entity Address, Address Line One 2800 Post Oak Boulevard, Suite 2600  
Entity Address, City or Town Houston  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 77056  
City Area Code 713  
Local Phone Number 629-7600  
Title of 12(b) Security Common Stock, $0.00001 par value  
Trading Symbol PWR  
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   138,020,980