Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v2.4.1.9
Document and Entity Information (USD $)
In Billions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Feb. 23, 2015
Jun. 30, 2014
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2014    
Document Fiscal Year Focus 2014    
Document Fiscal Period Focus FY    
Trading Symbol PWR    
Entity Registrant Name QUANTA SERVICES INC    
Entity Central Index Key 0001050915    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   204,133,234dei_EntityCommonStockSharesOutstanding  
Entity Public Float     $ 7.3dei_EntityPublicFloat
Series F Preferred Stock [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   1dei_EntityCommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesFPreferredStockMember
 
Series G Preferred Stock [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   1dei_EntityCommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesGPreferredStockMember
 
Exchangeable Shares Associated with Series F Preferred Stock [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   3,500,000dei_EntityCommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= pwr_ExchangeableSharesAssociatedWithSeriesFPreferredStockMember
 
Exchangeable Shares Associated with Series G Preferred Stock [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   899,858dei_EntityCommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= pwr_ExchangeableSharesAssociatedWithSeriesGPreferredStockMember
 
Exchangeable Shares Not Associated with Preferred Stock [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   2,926,113dei_EntityCommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= pwr_ExchangeableSharesNotAssociatedWithPreferredStockMember