Annual report pursuant to Section 13 and 15(d)

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

v3.19.3.a.u2
Selected Balance Sheet Data - Schedule of Other Assets (Parenthetical) (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Other Assets [Line Items]      
Allowance of doubtful accounts $ 512 $ 514  
Provision of bad debt expense 114 291 $ 219
Write-off receivables 116 271 $ 38
Reduction of accrued bonuses and other employee related expenses in settlement of employee notes receivable $ 60 $ 192  
Minimum [Member]      
Other Assets [Line Items]      
Notes receivable due period 1 year    
Maximum [Member]      
Other Assets [Line Items]      
Notes receivable due period 5 years