Quarterly report pursuant to Section 13 or 15(d)

Notes Payable to Former Stockholders - Schedule of Interest Expense Pertaining to Notes (Detail)

v3.10.0.1
Notes Payable to Former Stockholders - Schedule of Interest Expense Pertaining to Notes (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Interest Expense [Line Items]        
Interest expense $ 352 $ 374 $ 712 $ 756
Notes Payable to Former Stockholders [Member]        
Interest Expense [Line Items]        
Interest expense $ 102 $ 113 $ 211 $ 235