Property, Plant and Equipment (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Property, Plant and Equipment [Line Items]    
Land 10,848 $ 10,920
Vehicles and machinery 114,860 114,150
Buildings and improvements 19,489 [1] 19,365 [1]
Office fixtures and equipment 35,198 33,942
Property, plant and equipment 180,395 178,377
Accumulated depreciation (63,660) (65,202)
Property, plant and equipment, net 116,735 $ 113,175
Vehicles and machinery | Minimum    
Property, Plant and Equipment [Line Items]    
Residual Value as Percentage of Original Cost 0.00%  
Estimated useful life in years 5 years  
Vehicles and machinery | Maximum    
Property, Plant and Equipment [Line Items]    
Residual Value as Percentage of Original Cost 55.00%  
Estimated useful life in years 30 years  
Buildings and improvements | Minimum    
Property, Plant and Equipment [Line Items]    
Residual Value as Percentage of Original Cost 0.00% [1]  
Estimated useful life in years 3 years [1]  
Buildings and improvements | Maximum    
Property, Plant and Equipment [Line Items]    
Residual Value as Percentage of Original Cost 25.00% [1]  
Estimated useful life in years 30 years [1]  
Office fixtures and equipment    
Property, Plant and Equipment [Line Items]    
Residual Value as Percentage of Original Cost 0.00%  
Office fixtures and equipment | Minimum    
Property, Plant and Equipment [Line Items]    
Estimated useful life in years 3 years  
Office fixtures and equipment | Maximum    
Property, Plant and Equipment [Line Items]    
Estimated useful life in years 5 years  
Land    
Property, Plant and Equipment [Line Items]    
Residual Value as Percentage of Original Cost 0.00%  
[1] Improvements made to leased properties are amortized over the lesser of the estimated remaining life or the remaining term of the respective lease.