Property, Plant and Equipment - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Property, Plant and Equipment [Line Items]      
Construction in progress $ 1,200 $ 1,900  
Depreciation expense included in operating expense 27,200 31,873 $ 34,436
Impairment of PP&E held for sale 3,791 0 0
Oil & Gas and Utility T&D Segments      
Property, Plant and Equipment [Line Items]      
Impairment of PP&E held for sale 3,300    
Operating Expense      
Property, Plant and Equipment [Line Items]      
Depreciation expense included in operating expense $ 17,300 $ 22,000 $ 24,500