Quarterly report pursuant to Section 13 or 15(d)

Business and Organization - Additional Information (Detail)

v3.2.0.727
Business and Organization - Additional Information (Detail)
$ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Aug. 04, 2015
USD ($)
Sep. 30, 2015
USD ($)
Entity
Jun. 30, 2015
Entity
Mar. 31, 2015
Entity
Jun. 30, 2015
Entity
Segment
Dec. 31, 2014
Entity
Organization And Description Of Business [Line Items]            
Number of reportable segments | Segment         2  
Number of business acquisitions     3 3 6 9
Electric Power Infrastructure Services Business [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions         4  
Electric Power Infrastructure Services Business [Member] | Canada [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions     1 1 2 4
Electric Power Infrastructure Services Business [Member] | Australia [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions           1
Electric Power Infrastructure Services Business [Member] | Australia [Member] | Scenario Forecast [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions   1        
Electric Power Infrastructure Services Business [Member] | United States [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions     2   2 1
Electric Power Infrastructure Services Business [Member] | United States [Member] | Scenario Forecast [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions   2        
Oil and Gas Infrastructure Services Business [Member] | Canada [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions       1 1 2
Oil and Gas Infrastructure Services Business [Member] | Australia [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions       1 1  
Oil and Gas Infrastructure Services Business [Member] | United States [Member]            
Organization And Description Of Business [Line Items]            
Number of business acquisitions           1
Fiber Optic Licensing Division [Member] | Scenario Forecast [Member]            
Organization And Description Of Business [Line Items]            
Gain on sale, Net of tax | $   $ 175        
Fiber Optic Licensing Division [Member] | Subsequent Event [Member]            
Organization And Description Of Business [Line Items]            
Sales price of fiber optic licensing operations | $ $ 1,000          
Net cash proceeds from sale of fiber optic licensing operations | $ $ 830