Annual report pursuant to Section 13 and 15(d)

SHARE-BASED PAYMENTS - Narrative (Details)

v3.23.3
SHARE-BASED PAYMENTS - Narrative (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Sep. 30, 2023
Sep. 30, 2022
Sep. 30, 2021
Nov. 30, 2021
Share-based compensation, aggregate disclosures [Abstract]        
Total stock-based compensation cost $ 17,308 $ 17,432 $ 15,581  
Restricted Stock        
Share-based compensation, aggregate disclosures [Abstract]        
Percent of shares vested on time 43.00%      
Stock Options        
Share-based compensation, aggregate disclosures [Abstract]        
Award vesting period 3 years      
Expiration period (in years) 5 years      
Equity Incentive Plan 2017        
Share-based compensation, aggregate disclosures [Abstract]        
Term of plan (in years) 10 years      
Shares reserved for future issuance under award plan (in shares)       3,450,000
Shares issued (in shares) 496,508      
Grants in period (in shares) 75,000   75,000  
Share-based awards outstanding (in shares) 1,803,697      
Grants in period, exercise price (in dollars per share)     $ 41.70  
Equity Incentive Plan 2017 | Time-Based Restricted Share Units        
Share-based compensation, aggregate disclosures [Abstract]        
Grants in period (in shares) 1,041,615      
Equity Incentive Plan 2017 | Performance-Based Restricted Share Units        
Share-based compensation, aggregate disclosures [Abstract]        
Grants in period (in shares) 1,313,162      
All Plans        
Share-based compensation, aggregate disclosures [Abstract]        
Total stock-based compensation cost $ 17,308 17,432 $ 15,581  
Future income tax benefit from compensation expense recognized 3,821 $ 3,821 $ 3,247  
Unrecognized compensation cost on unvested awards $ 18,305      
Weighted average period of recognition of unrecognized compensation cost on non-vested awards 1 year 10 months 24 days      
All Plans | Restricted Stock        
Share-based compensation, aggregate disclosures [Abstract]        
Grants in period (in shares) 618,050      
Unvested shares (in shares) 1,728,697 1,459,233    
Amended 2017 Plan        
Share-based compensation, aggregate disclosures [Abstract]        
Percentage of outstanding stock, maximum 200.00%      
Director Fee Plans        
Share-based compensation, aggregate disclosures [Abstract]        
Shares deferred under the director fee plan (in shares) 45,218      
Value of annual stock-based grant $ 140      
Director Fee Plans | Restricted Stock        
Share-based compensation, aggregate disclosures [Abstract]        
Grants in period (in shares) 336,127      
2019 Director Fee Plan        
Share-based compensation, aggregate disclosures [Abstract]        
Shares reserved for future issuance under award plan (in shares) 300,000      
Annual retainer fee paid to non-employee directors $ 90      
Annual retainer fee paid to non-employee chairman of the board $ 210      
2019 Director Fee Plan | Restricted Stock        
Share-based compensation, aggregate disclosures [Abstract]        
Grants in period (in shares) 162,898      
Unvested shares (in shares) 60,057      
Tranche One | Restricted Stock        
Share-based compensation, aggregate disclosures [Abstract]        
Vesting percentage 50.00%      
Tranche One | Stock Options        
Share-based compensation, aggregate disclosures [Abstract]        
Vesting percentage 33.33%      
Tranche Two | Restricted Stock        
Share-based compensation, aggregate disclosures [Abstract]        
Vesting percentage 25.00%      
Tranche Two | Stock Options        
Share-based compensation, aggregate disclosures [Abstract]        
Vesting percentage 33.33%      
Tranche Three | Restricted Stock        
Share-based compensation, aggregate disclosures [Abstract]        
Vesting percentage 25.00%      
Tranche Three | Stock Options        
Share-based compensation, aggregate disclosures [Abstract]        
Vesting percentage 33.33%