Accrued Liabilities (Detail) - USD ($)
$ in Thousands
Sep. 30, 2016
Dec. 31, 2015
Payables and Accruals [Abstract]    
Accrued payroll and employee benefits $ 1,402 $ 5,839
Accrued insurance 4,546 5,896
Accrued legal and environmental costs 1,595 1,531
Accrued taxes (Note 11) 2,629 1,514
Accrued interest (Note 8) 2,040 8,516
Accrued operating costs 4,231 4,233
Accrued other 1,838 2,314
Total accrued liabilities $ 18,281 $ 29,843