Quarterly report pursuant to Section 13 or 15(d)

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

v3.7.0.1
Selected Balance Sheet Data - Schedule of Other Assets (Parenthetical) (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Other Assets [Line Items]          
Allowance of doubtful accounts $ 249   $ 249   $ 313
(Recovery) provision for bad debt expense (10) $ (13) (54) $ 3  
Write-off receivables $ (6) $ 11 $ 10 $ 65  
Minimum [Member]          
Other Assets [Line Items]          
Notes receivable due period     1 year    
Maximum [Member]          
Other Assets [Line Items]          
Notes receivable due period     5 years