Quarterly report pursuant to Section 13 or 15(d)

Stockholder's Equity - Additional Information (Details)

v3.20.2
Stockholder's Equity - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Mar. 31, 2014
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2006
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Total unrecognized compensation cost related to nonvested shares of common stock granted $ 33,700             $ 33,700      
Weighted average period of cost recognized               3 years 14 days      
Compensation expense related to nonvested stock grants               $ 11,100 $ 6,400    
Price of shares issued under Employee Stock Purchase Plan as a percentage of FMV                   95.00%  
Number of shares reserved for the Employee Stock Purchase Plan (in shares)                   250,000  
Additional shares authorized for issuance (in shares)             250,000        
Shares redeemed to satisfy personal tax obligations (in shares)               7,328      
Treasury shares redeemed to pay income tax 966 $ 1,139 $ 6,933 $ 140 $ 700 $ 6,841          
Stock repurchased               $ 800      
Exercise of options $ (601) $ (304)   $ (529) $ (212) $ (850)   $ 900      
Employee                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Shares redeemed to satisfy personal tax obligations (in shares)               70,676      
Treasury shares redeemed to pay income tax               $ 9,000      
2018 Long-Term Incentive Plan                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Common stock reserved for issuance (in shares)                     2,210,544
Common stock available for issuance (in shares)                     1,874,354
2018 Long-Term Incentive Plan | Employee                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Period of vested shares               5 years      
Nonvested stock grants to employees (in shares)               113,525      
2018 Long-Term Incentive Plan | Consultants                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Nonvested stock grants to employees (in shares)               10,890      
Second Amended and Restated 2005 Non-Employee Directors Compensation Plan                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Nonvested stock grants to Independent directors (in shares)               775      
Percentage of directors' stock grant vested on one year anniversary date               100.00%      
Period of vested shares               1 year      
Second Amended and Restated 2005 Non-Employee Directors Compensation Plan | Director                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Nonvested stock grants to Independent directors (in shares)               9,900      
Percentage of directors' stock grant vested on grant date               100.00%