Annual report pursuant to Section 13 and 15(d)

Equity-Based Compensation (Details)

v3.21.2
Equity-Based Compensation (Details) - Restricted Stock - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Aggregate grant date fair value $ 13.6 $ 13.6   $ 3.8
Class A Common Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted (in shares) 510,733     292,534
Class A Common Stock | Non-Employee Directors Under the Equity Incentive Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Compensation expense   1.3 $ 1.6 $ 0.5
Unrecognized compensation expense $ 0.4 $ 0.4    
Class A Common Stock | Equity Incentive Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted (in shares)   510,733    
Compensation expense   $ 2.2    
Unrecognized compensation expense $ 11.4 $ 11.4