Annual report pursuant to Section 13 and 15(d)

Subsequent Events (Detail)

v3.22.2.2
Subsequent Events (Detail)
$ in Millions
 12 Months Ended
Nov. 18, 2022
USD ($)
Nov. 04, 2022
shares
Nov. 03, 2022
USD ($)
shares
Sep. 30, 2022
USD ($)
shares
Sep. 30, 2021
shares
Sep. 30, 2020
shares
Restricted Stock            
Subsequent Event [Line Items]            
Granted (in shares) | shares       256,167 510,733 0
Performance Stock Units            
Subsequent Event [Line Items]            
Aggregate grant date fair value | $       $ 3.0    
Granted (in shares) | shares       131,341    
Performance Stock Units | Minimum            
Subsequent Event [Line Items]            
Percentage of final number of of common stock issuable upon vesting of performance stock units       0    
Performance Stock Units | Maximum            
Subsequent Event [Line Items]            
Percentage of final number of of common stock issuable upon vesting of performance stock units       1.50    
Percentage increase (decrease) of awards granted due to total shareholder return ranking       0.15    
Subsequent Event            
Subsequent Event [Line Items]            
Maximum cash proceeds from disposal of property or assets allowable without prepayment of outstanding indebtedness | $ $ 10.0          
Period allowed for reinvestment of net cash proceeds from disposal of property or assets under credit agreement 180 days          
Period allowed for reinvestment of net cash proceeds from disposal of property or assets under credit agreement after entering definitive agreement 180 days          
Prepayment of outstanding indebtedness allowed if reinvestment of net cash proceeds from disposal of property or assets under credit agreement received 180 days          
Business combination, consideration received | $ $ 28.0          
Subsequent Event | Restricted Stock            
Subsequent Event [Line Items]            
Vesting period     4 years      
Aggregate grant date fair value | $     $ 4.6      
Subsequent Event | Performance Stock Units            
Subsequent Event [Line Items]            
Vesting period     3 years      
Aggregate grant date fair value | $     $ 2.6      
Subsequent Event | Performance Stock Units | Minimum            
Subsequent Event [Line Items]            
Percentage of final number of of common stock issuable upon vesting of performance stock units     0      
Subsequent Event | Performance Stock Units | Maximum            
Subsequent Event [Line Items]            
Percentage of final number of of common stock issuable upon vesting of performance stock units     150      
Percentage increase (decrease) of awards granted due to total shareholder return ranking     0.15      
Subsequent Event | Class A Common Stock            
Subsequent Event [Line Items]            
Treasury stock acquired (in shares) | shares   5,267        
Subsequent Event | Class A Common Stock | Restricted Stock            
Subsequent Event [Line Items]            
Issuance of stock grant awards (in shares) | shares     150,798      
Subsequent Event | Class A Common Stock | Performance Stock Units            
Subsequent Event [Line Items]            
Granted (in shares) | shares     84,371