Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information (Detail)

v3.3.1.900
Commitments and Contingencies - Additional Information (Detail)
 1 Months Ended 3 Months Ended 12 Months Ended
Jan. 31, 2016
USD ($)
Oct. 09, 2013
USD ($)
Jan. 31, 2016
USD ($)
Dec. 31, 2014
USD ($)
Mar. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Customer
Agency
km
Dec. 31, 2014
USD ($)
Customer
Dec. 31, 2013
USD ($)
Customer
Jul. 31, 2014
USD ($)
Apr. 21, 2010
mi
Commitment And Contingencies [Line Items]                    
Outstanding capital commitment           $ 7,400,000        
Rent expense related to operating leases           208,500,000 $ 161,500,000 $ 111,800,000    
Maximum guaranteed residual value           $ 487,100,000        
Number of customers representing ten percent or more of consolidated revenues | Customer           0 0 0    
Number of customers representing ten percent or more of net position | Customer           1        
Gross amount accrued for insurance claims       $ 170,200,000   $ 209,000,000 $ 170,200,000      
Long-term insurance claims       130,800,000   153,500,000 130,800,000      
Related insurance recoveries/receivables       9,100,000   8,600,000 9,100,000      
Related insurance recoveries/receivables included in prepaid expenses and other current assets       800,000   600,000 800,000      
Related insurance recoveries/receivables included in other assets net       8,300,000   8,000,000 $ 8,300,000      
Letters of credit and bank guarantees under the credit facility           307,000,000        
Total amount of outstanding performance bonds           2,600,000,000        
Estimated cost to complete bonded projects           906,000,000        
Multiemployer plan withdrawal obligation, amount suggested by Plan which is different than amount recorded by company   $ 6,900,000                
Multiemployer plan withdrawal obligation complete withdrawal   4,800,000                
Multiemployer plan withdrawal obligation accrued           2,100,000        
Cash proceeds deposited in Escrow account   $ 2,100,000                
Pre-acquisition non-U.S.tax obligations and indemnification asset amount recorded           11,400,000        
Pre-acquisition non-U.S.tax obligations and indemnification liability amount recorded           $ 11,400,000        
Subsequent Event [Member] | 2013 Central States Plan [Member]                    
Commitment And Contingencies [Line Items]                    
Amount of withdrawal liability $ 4,800,000   $ 4,800,000              
Payment of withdrawal liability amount 2,700,000                  
Alberta Power Line [Member]                    
Commitment And Contingencies [Line Items]                    
Length of electrical transmission line to be constructed under contract | km           500        
Sunrise Powerlink Project [Member]                    
Commitment And Contingencies [Line Items]                    
Length of electrical transmission line to be constructed under contract | mi                   117
Proceeds from customers       $ 65,000,000            
Net Position [Member] | Customer Concentration Risk [Member] | Quanta's Electric Power Infrastructure Services Segment [Member]                    
Commitment And Contingencies [Line Items]                    
Concentration risk percentage           12.00%        
Scenario Forecast [Member]                    
Commitment And Contingencies [Line Items]                    
Outstanding capital commitment         $ 1,300,000          
June 1, 2017 [Member]                    
Commitment And Contingencies [Line Items]                    
Outstanding capital commitment           $ 6,100,000        
Vehicle Fleet Committed Capital [Member]                    
Commitment And Contingencies [Line Items]                    
Estimated committed capital in next fiscal year           $ 2,300,000        
Central States Plan [Member]                    
Commitment And Contingencies [Line Items]                    
Amount of withdrawal liability                 $ 39,600,000  
Central States Plan [Member] | Subsequent Event [Member]                    
Commitment And Contingencies [Line Items]                    
Amount of withdrawal liability $ 32,900,000   32,900,000              
Payment of withdrawal liability amount     $ 11,000,000              
Minimum [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]                    
Commitment And Contingencies [Line Items]                    
Concentration risk percentage           10.00% 10.00% 10.00%    
Minimum [Member] | Net Position [Member] | Customer Concentration Risk [Member]                    
Commitment And Contingencies [Line Items]                    
Concentration risk percentage           10.00% 10.00%      
Minimum [Member] | Central States Plan [Member]                    
Commitment And Contingencies [Line Items]                    
Amount of withdrawal liability           $ 40,100,000        
Maximum [Member] | Central States Plan [Member]                    
Commitment And Contingencies [Line Items]                    
Amount of withdrawal liability           $ 55,400,000        
Lorenzo Benton v Telecom Network Specialists Inc [Member]                    
Commitment And Contingencies [Line Items]                    
Number of staffing Agency | Agency           29        
Lorenzo Benton v Telecom Network Specialists Inc [Member] | Class Damage [Member]                    
Commitment And Contingencies [Line Items]                    
Amount sought by plaintiff           $ 16,000,000        
Lorenzo Benton v Telecom Network Specialists Inc [Member] | Attorney Fees [Member]                    
Commitment And Contingencies [Line Items]                    
Amount sought by plaintiff           $ 5,000,000