Annual report pursuant to Section 13 and 15(d)

Equity - Narrative (Details)

v3.21.2
Equity - Narrative (Details) - USD ($)
$ / shares in Units, shares in Thousands
12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Mar. 31, 2020
Stock-based compensation        
Deferred vested award (in shares) 268      
Intrinsic value vested $ 59,000,000      
Share-based compensation expense 28,600,000 $ 23,700,000 $ 20,800,000  
Income tax benefit recognized 13,500,000 $ 8,000,000 $ 9,900,000  
Unrecognized compensation cost $ 45,700,000      
Unrecognized compensation costs, period for recognition 1 year 3 months 18 days      
Granted (in dollars per share) $ 76.80      
Stock repurchase programs, authorized amount       $ 200,000,000
Common shares repurchased (in shares) 100 2,800 700  
Common shares repurchased, cost $ 3,363,000 $ 166,959,000 $ 46,797,000  
Amount remaining available for future stock repurchases $ 146,700,000      
Performance Stock Units        
Stock-based compensation        
Vesting period 3 years      
Unrecognized compensation costs, period for recognition 3 years      
Performance Stock Units | Minimum        
Stock-based compensation        
Vesting rights, percentage 0.00%      
Performance Stock Units | Maximum        
Stock-based compensation        
Vesting rights, percentage 200.00%      
Restricted Stock Units        
Stock-based compensation        
Granted (in dollars per share)   $ 74.26 $ 66.96  
Total fair value $ 28,900,000 $ 23,600,000 $ 27,400,000  
Restricted Stock Units | Member of Board of Directors        
Stock-based compensation        
Vesting period 1 year      
Restricted Stock Units | Minimum        
Stock-based compensation        
Vesting period 4 years      
Restricted Stock Units | Maximum        
Stock-based compensation        
Vesting period 5 years