v3.24.3
Stock-Based Compensation Plans - Stock Appreciation Rights Award Activity (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Sep. 30, 2024
Sep. 30, 2023
Sep. 30, 2022
Post Cash Settled      
Stock Appreciation Rights      
Total Share-based Liabilities Paid $ 1.3 $ 1.4 $ 1.1
Granted 1,910    
Forfeited 0    
Post Stock Settled      
Stock Appreciation Rights      
Outstanding 29,656 51,898  
Granted 0    
Exercised (22,242)    
Forfeited 0    
Expired 0    
Vested And Expected To Vest 29,656    
Exercisable 29,656    
Outstanding, Weighted Average Exercise Price $ 37.53 $ 36.35  
Granted, Weighted Average Exercise Price    
Exercised, Weighted Average Exercise Price 34.79    
Forfeited, Weighted Average Exercise Price    
Expired, Weighted Average Exercise Price    
Vested And Expected To Vest, Weighted Average Exercise Price 37.53    
Exercisable, Weighted Average Exercise Price $ 37.53    
Outstanding, Weighted Average Remaining Contractual Term 7 months 17 days    
Vested And Expected To Vest, Outstanding, Weighted Average Remaining Contractual Term 7 months 17 days    
Exercisable, Weighted Average Remaining Contractual Term 7 months 17 days    
Outstanding, Intrinsic Value $ 2.3    
Vested And Expected To Vest, Outstanding, Aggregate Intrinsic Value 2.3    
Exercisable, Aggregate Intrinsic Value 2.3    
Exercised, Total Intrinsic Value $ 1.4 $ 1.9 $ 3.0