Annual report pursuant to Section 13 and 15(d)

Common Stock and Options - Narrative (Details)

v3.21.2
Common Stock and Options - Narrative (Details) - USD ($)
1 Months Ended 12 Months Ended
Nov. 10, 2020
Oct. 11, 2019
Feb. 11, 2019
Oct. 25, 2018
Sep. 07, 2018
Dec. 31, 2016
Nov. 30, 2017
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Oct. 15, 2019
Oct. 10, 2019
Oct. 03, 2018
May 31, 2017
Mar. 31, 2017
Feb. 27, 2015
Class Of Stock [Line Items]                                
Number of shares authorized to be repurchased (up to)                     7,000 7,000   2,000,000 5,000,000  
Total stock-based compensation expense               $ 1,230,000 $ 1,306,000 $ 824,000            
Employee stock options granted (in shares)               0 118,000 10,000            
Shares issued (in dollars per share)                         $ 34.00      
Period of consecutive trading days     20 days                          
Common shares available               218,000 293,000 227,500            
Restricted Stock                                
Class Of Stock [Line Items]                                
Award vesting period             2 years 6 months                  
Total stock-based compensation expense               $ 144,000 $ 69,000 $ 104,000            
Number of restricted shares awarded 5,885           5,000 5,885                
Weighted average fair value (in dollars per share) $ 31.20           $ 31.95 $ 31.20                
Number of restricted shares vested               0 5,666 1,667            
Unrecognized expense               $ 40,000 $ 0              
Aggregate value of shares vested                 251,000 $ 53,000            
Options                                
Class Of Stock [Line Items]                                
Total stock-based compensation expense               242,000 504,000 674,000            
Unrecognized expense               134,000 $ 376,000              
Unrecognized compensation cost, expected recognition period                 8 months 19 days              
Board of Directors Fees                                
Class Of Stock [Line Items]                                
Total stock-based compensation expense               $ 844,000,000 $ 733,000,000 $ 869,000,000            
Maximum [Member]                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)     $ 35.00                          
2015 Option Grants                                
Class Of Stock [Line Items]                                
Number of shares authorized to be repurchased (up to)                               1,250,000
2015 Option Grants | Options                                
Class Of Stock [Line Items]                                
Common shares available               1,014,500                
2015 Option Grants | Minimum                                
Class Of Stock [Line Items]                                
Award vesting period               1 year                
2015 Option Grants | Maximum [Member]                                
Class Of Stock [Line Items]                                
Award vesting period               6 years                
2020 Option Grants                                
Class Of Stock [Line Items]                                
Employee stock options granted (in shares)   118,000                            
Shares issued (in dollars per share)   $ 33.96                            
Percentage of options                 25.00%              
Period following an executive's termination of employment for a number of reasons   18 months                            
Period following an executive's termination of employment without cause   12 months                            
Number of awards vesting (in shares)               0                
2020 Option Grants | Tranche One                                
Class Of Stock [Line Items]                                
Percentage of options   25.00%                            
Period of consecutive trading days   20 days                            
Amount per share (in dollars per share)   $ 35.00                            
2020 Option Grants | Tranche Two                                
Class Of Stock [Line Items]                                
Percentage of options   25.00%                            
Period of consecutive trading days   20 days                            
Amount per share (in dollars per share)   $ 40.00                            
2020 Option Grants | Tranche Three                                
Class Of Stock [Line Items]                                
Percentage of options   25.00%                            
Period of consecutive trading days   20 days                            
Amount per share (in dollars per share)   $ 45.00                            
2020 Option Grants | Tranche Four                                
Class Of Stock [Line Items]                                
Percentage of options   25.00%                            
Period of consecutive trading days   20 days                            
Amount per share (in dollars per share)   $ 50.00                            
2020 Option Grants | Options                                
Class Of Stock [Line Items]                                
Grants in period, weighted average (in dollars per share)               $ 3.20                
2020 Option Grants | Minimum                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)               $ 40.00 $ 35.00              
2020 Option Grants | Maximum [Member]                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)                 $ 35.00              
2019 Option Grants                                
Class Of Stock [Line Items]                                
Shares issued (in dollars per share)       $ 33.34                        
Period following an executive's termination of employment for a number of reasons       18 months                        
Period following an executive's termination of employment without cause       12 months                        
Number of awards vesting (in shares)               0                
2019 Option Grants | Tranche One                                
Class Of Stock [Line Items]                                
Period of consecutive trading days       20 days                        
Amount per share (in dollars per share)       $ 40.00                        
Number of awards vesting (in shares)       3,333                        
2019 Option Grants | Tranche Two                                
Class Of Stock [Line Items]                                
Period of consecutive trading days       20 days                        
Amount per share (in dollars per share)       $ 45.00                        
Number of awards vesting (in shares)       3,333                        
2019 Option Grants | Tranche Three                                
Class Of Stock [Line Items]                                
Period of consecutive trading days       20 days                        
Amount per share (in dollars per share)       $ 50.00                        
Number of awards vesting (in shares)       3,334                        
2019 Option Grants | Options                                
Class Of Stock [Line Items]                                
Grants in period, weighted average (in dollars per share)               $ 7.10                
2019 Option Grants | Chief Financial Officer                                
Class Of Stock [Line Items]                                
Employee stock options granted (in shares)       10,000                        
2019 Option Grants | Maximum [Member]                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)               $ 40.00                
2018 Option Grants                                
Class Of Stock [Line Items]                                
Shares issued (in dollars per share)         $ 33.60                      
Percentage of options                 25.00%              
Period following an executive's termination of employment for a number of reasons         18 months                      
Period following an executive's termination of employment without cause         12 months                      
Number of awards vesting (in shares)               0                
2018 Option Grants | Tranche One                                
Class Of Stock [Line Items]                                
Percentage of options         25.00%                      
Period of consecutive trading days         20 days                      
Amount per share (in dollars per share)         $ 35.00                      
2018 Option Grants | Tranche Two                                
Class Of Stock [Line Items]                                
Percentage of options         25.00%                      
Period of consecutive trading days         20 days                      
Amount per share (in dollars per share)         $ 40.00                      
2018 Option Grants | Tranche Three                                
Class Of Stock [Line Items]                                
Percentage of options         25.00%                      
Period of consecutive trading days         20 days                      
Amount per share (in dollars per share)         $ 45.00                      
2018 Option Grants | Tranche Four                                
Class Of Stock [Line Items]                                
Percentage of options         25.00%                      
Period of consecutive trading days         20 days                      
Amount per share (in dollars per share)         $ 50.00                      
2018 Option Grants | Chief Financial Officer                                
Class Of Stock [Line Items]                                
Employee stock options granted (in shares)         90,000                      
2018 Option Grants | Chief Executive Officer                                
Class Of Stock [Line Items]                                
Employee stock options granted (in shares)         210,000                      
2018 Option Grants | Chief Executive Officer | Tranche One                                
Class Of Stock [Line Items]                                
Period of consecutive trading days     20 days                          
Amount per share (in dollars per share)     $ 35.00                          
Number of shares expected to vest (in shares)     26,250                          
2018 Option Grants | Chief Executive Officer | Tranche Two                                
Class Of Stock [Line Items]                                
Period of consecutive trading days     20 days                          
Amount per share (in dollars per share)     $ 40.00                          
Number of shares expected to vest (in shares)     26,250                          
2018 Option Grants | Minimum                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)                 $ 35.00              
2018 Option Grants | Maximum [Member]                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)               $ 40.00                
2016 Option Grants                                
Class Of Stock [Line Items]                                
Shares issued (in dollars per share)           $ 27.15                    
Period following an executive's termination of employment for a number of reasons           18 months                    
Number of awards vesting (in shares)               0                
2016 Option Grants | Tranche One                                
Class Of Stock [Line Items]                                
Percentage of options           25.00%                    
Period of consecutive trading days           20 days                    
Amount per share (in dollars per share)           $ 60.00                    
2016 Option Grants | Tranche Two                                
Class Of Stock [Line Items]                                
Percentage of options           25.00%                    
Period of consecutive trading days           20 days                    
Amount per share (in dollars per share)           $ 75.00                    
2016 Option Grants | Tranche Three                                
Class Of Stock [Line Items]                                
Percentage of options           25.00%                    
Period of consecutive trading days           20 days                    
Amount per share (in dollars per share)           $ 90.00                    
2016 Option Grants | Tranche Four                                
Class Of Stock [Line Items]                                
Percentage of options           25.00%                    
Period of consecutive trading days           20 days                    
Amount per share (in dollars per share)           $ 105.00                    
2016 Option Grants | Chief Executive Officer                                
Class Of Stock [Line Items]                                
Employee stock options granted (in shares)           300,000                    
2016 Option Grants | Board of Directors Chairman                                
Class Of Stock [Line Items]                                
Employee stock options granted (in shares)           225,000                    
2016 Option Grants | Maximum [Member]                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)               $ 60.00                
2019 Option Grants | Options                                
Class Of Stock [Line Items]                                
Grants in period, weighted average (in dollars per share)               $ 1.40                
2019 Option Grants | Chief Executive Officer | Tranche One                                
Class Of Stock [Line Items]                                
Shares forfeited (in shares)     26,250                          
2019 Option Grants | Chief Executive Officer | Tranche Two                                
Class Of Stock [Line Items]                                
Period of consecutive trading days     20 days                          
Shares forfeited (in shares)     26,250                          
2019 Option Grants | Maximum [Member] | Chief Executive Officer | Tranche Two                                
Class Of Stock [Line Items]                                
Share price (in dollars per share)     $ 40.00