Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Summary of Exercise Price for Stock Options Outstanding and Exercisable (Details)

v3.21.1
Stock-Based Compensation - Summary of Exercise Price for Stock Options Outstanding and Exercisable (Details) - $ / shares
Mar. 31, 2021
Sep. 30, 2020
Sep. 30, 2019
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 120,418 119,168 200,418
Option exercise price outstanding $ 19.12 $ 19.07 $ 16.37
Number of options exercisable 107,168 95,001  
Option exercise price exercisable $ 16.71 $ 15.50  
$10.00      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 25,000    
Option exercise price outstanding $ 10.00    
Number of options exercisable 25,000    
Option exercise price exercisable $ 10.00    
$10.86      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 16,668    
Option exercise price outstanding $ 10.86    
Number of options exercisable 16,668    
Option exercise price exercisable $ 10.86    
$12.50      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 6,250    
Option exercise price outstanding $ 12.50    
Number of options exercisable 6,250    
Option exercise price exercisable $ 12.50    
$15.00      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 6,250    
Option exercise price outstanding $ 15.00    
Number of options exercisable 6,250    
Option exercise price exercisable $ 15.00    
$15.18      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 25,000    
Option exercise price outstanding $ 15.18    
Number of options exercisable 25,000    
Option exercise price exercisable $ 15.18    
$23.41      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 8,000    
Option exercise price outstanding $ 23.41    
Number of options exercisable 8,000    
Option exercise price exercisable $ 23.41    
$23.89      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 1,250    
Option exercise price outstanding $ 23.89    
$27.60      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 8,000    
Option exercise price outstanding $ 27.60    
Number of options exercisable 8,000    
Option exercise price exercisable $ 27.60    
$31.74      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 8,000    
Option exercise price outstanding $ 31.74    
Number of options exercisable 8,000    
Option exercise price exercisable $ 31.74    
$36.50      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 8,000    
Option exercise price outstanding $ 36.50    
Number of options exercisable 4,000    
Option exercise price exercisable $ 36.50    
$41.98      
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]      
Number of options outstanding 8,000    
Option exercise price outstanding $ 41.98