Accrued Payroll and Employee Benefits - Components of Accrued Payroll and Employee Benefits (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued payroll	$ 156	$ 1,131
Accrued benefits	1,672	1,685
Accrued severance	1,632	1,440
Total accrued payroll and employee benefits	$ 3,460	$ 4,256