Annual report pursuant to Section 13 and 15(d)

Share-based Compensation - Additional Information (Detail)

v3.19.3.a.u2
Share-based Compensation - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2019
USD ($)
Plan
shares
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of incentive plans | Plan 2    
Unrecognized compensation expense $ 4,500,000    
Weighted average period cost expected to be recognized 2 years    
Stock options, expiration term from date of grant 10 years    
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Period of continuous service 3 years    
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Period of continuous service 5 years    
2013 Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares of common stock to be granted under equity incentive awards | shares 1,500,000    
Shares available for issuance under the Plan | shares 348,922    
2007 and 2013 Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation expense $ 0    
Options granted in period (shares) | shares 0    
Stock options, expiration term from date of grant 10 years    
2007 and 2013 Plan | Restricted stock awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation expense $ 4,500,000    
Weighted average period cost expected to be recognized 2 years    
Total fair value of vested shares $ 2,100,000 $ 3,000,000.0 $ 4,200,000
2007 and 2013 Plan | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Period of continuous service 3 years    
2007 and 2013 Plan | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Period of continuous service 5 years