Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payments - Narrative (Details)

v3.21.1
Share-Based Payments - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2021
Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation cost $ 4,001 $ 2,508 $ 7,247 $ 4,539
Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares issued under the 2017 Equity incentive plan     499,050  
Percent of shares vested on time     45.00%  
Unrecognized compensation cost on non-vested awards $ 17,602   $ 17,602  
Weighted average period of recognition of unrecognized compensation cost on non-vested awards     2 years 2 months 12 days  
Restricted stock awards unvested (in shares) 74,639   74,639  
Restricted Stock | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration period     3 years  
Restricted Stock | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration period     5 years  
Restricted Stock | After 3 Years        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting increment     50.00%  
Restricted Stock | Attainment of Pre-Defined Levels of Appreciation in Market Value        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting increment     25.00%  
Restricted Stock | Attainment of Pre-Defined Levels of Adjusted Earnings Per Share        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting increment     25.00%  
2017 Equity Incentive Plan | Stock Compensation Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Term of plan     10 years  
Maximum number of shares available for grants or awards (in shares) 1,700,000   1,700,000  
Shares reserved for future issuance under award plan (in shares) 1,700,000   1,700,000  
2017 Equity Incentive Plan | Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares issued under the 2017 Equity incentive plan     1,064,910  
Retirement Eligible Employees        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Future income tax benefit from compensation expense recognized $ 738 $ 614 $ 976 $ 793
2014 Director Fee Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Annual retainer fee paid to non-employee directors     85  
Annual retainer fee paid to non-employee Chairman of the Board     $ 185  
2019 Director Fee Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Maximum number of shares available for grants or awards (in shares) 150,000   150,000  
Director Fee Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares deferred under stock based compensation plan (in shares) 38,327   38,327  
Value of annual stock based grant     $ 125  
Total restricted stock awards granted to date (in shares) 271,807   271,807  
Restricted stock awards unvested (in shares) 98,578   98,578