XML 64 R51.htm IDEA: XBRL DOCUMENT v3.21.2
Shareholders' Equity and Stock-Based Compensation - Summary of Option Activity under Stock-Based Compensation Plan (Detail) - $ / shares
12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of Shares, Options exercised (51,508) (20,000)  
Number of Shares, Options outstanding 30,000 252,492 272,492
Number of Shares, Options expired 170,984    
Average Exercise Price Per Share, Options exercised $ 5.126 $ 5.126  
Average Exercise Price Per Share, Options outstanding 11.380 $ 6.205 $ 6.126
Average Exercise Price Per Share, Options expired $ 5.623