Annual report pursuant to Section 13 and 15(d)

Revenue Recognition - Narrative (Details)

v3.21.2
Revenue Recognition - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Disaggregation of Revenue [Line Items]    
Deferred revenue, revenue recognized $ 45.9 $ 54.6
Cumulative catch-up adjustment to revenue from change in estimates $ 20.9 $ (9.2)
Cumulative catch-up adjustment to diluted earnings per share from change in estimates (in dollars per share) $ 0.24 $ (0.10)
Unbilled receivables    
Disaggregation of Revenue [Line Items]    
Unbilled contracts receivable $ 10.4 $ 12.3
Performance-based | Future Outcomes | Transferred over Time    
Disaggregation of Revenue [Line Items]    
Deferred revenue, revenue recognized 104.7 45.0
Estimate of fees upon target $ 48.7 $ 24.8