Segment Information - Information about the Company's Operations (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Contract revenue:                      
Contract revenue $ 217,660 $ 222,191 $ 218,789 $ 250,354 $ 344,953 $ 448,134 $ 423,154 $ 378,129 $ 908,994 $ 1,594,370 $ 1,495,125
Property, plant and equipment, net:                      
Property, plant and equipment, net 50,352       85,649       50,352 85,649  
United States                      
Contract revenue:                      
Contract revenue                 676,460 1,189,781 1,049,743
Property, plant and equipment, net:                      
Property, plant and equipment, net 45,365       78,458       45,365 78,458  
Canada                      
Contract revenue:                      
Contract revenue                 232,534 404,589 445,213
Property, plant and equipment, net:                      
Property, plant and equipment, net 4,987       7,140       4,987 7,140  
Other                      
Contract revenue:                      
Contract revenue                 0 0 $ 169
Property, plant and equipment, net:                      
Property, plant and equipment, net $ 0       $ 51       $ 0 $ 51