v3.19.1
Stock-Based Compensation - Additional Information (Detail)
3 Months Ended
Mar. 31, 2019
USD ($)
$ / shares
shares
Jun. 30, 2018
USD ($)
Installment
shares
Mar. 31, 2018
USD ($)
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense | $ $ 0   $ 0
Stock options granted under equity incentive plans 0   0
Unrecognized compensation expense related to non-vested stock options | $ $ 0    
Fully-vested and exercisable stock options outstanding, number of shares 4,000    
Fully-vested and exercisable stock options outstanding, weighted average exercise price | $ / shares $ 31.89    
Fully-vested and exercisable stock options outstanding, weighted average remaining contractual life 1 year 5 months 12 days    
Total value of restricted stock award | $   $ 200,000  
Restricted Stock Award [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares granted   42,000  
Number of shares vested   17,000  
Number of shares expected to vest   25,000  
Number of equal vesting installments | Installment   4  
Restricted Stock Award [Member] | Prepaid Assets [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation expense related to non-vested restricted stock award | $ $ 30,000    
Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock option exercisable period 7 years    
2015 Equity Incentive Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares outstanding under equity incentive plans 4,000    
Common stock available for future issuance 756,000