Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.10.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2018
Aug. 03, 2018
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q2  
Trading Symbol PWR  
Entity Registrant Name QUANTA SERVICES INC  
Entity Central Index Key 0001050915  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Common Stock Class Undefined    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   148,807,552
Series G Preferred Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   1
Exchangeable Shares Associated with Series G Preferred Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   449,929
Exchangeable Shares Not Associated with Preferred Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   36,183