Quarterly report pursuant to Section 13 or 15(d)

Selected Balance Sheet Data - Schedule of Other Assets (Parenthetical) (Detail)

v3.19.1
Selected Balance Sheet Data - Schedule of Other Assets (Parenthetical) (Detail) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Other Assets [Line Items]      
Allowance of doubtful accounts $ 407   $ 514
Recovery for bad debt expense (104) $ (106)  
Write-off receivables 3 51  
Reduction of accrued bonuses and other employee related expenses in settlement of employee notes receivable $ 60 $ 131  
Minimum [Member]      
Other Assets [Line Items]      
Notes receivable due period 1 year    
Maximum [Member]      
Other Assets [Line Items]      
Notes receivable due period 5 years