Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies - Additional Information (Detail)

v3.20.2
Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Sep. 30, 2020
USD ($)
state
reporting_unit
Sep. 30, 2019
USD ($)
reporting_unit
Summary Of Accounting Policies [Line Items]    
Revisions in estimates related to amounts recorded in prior periods for revenue $ 1,600,000 $ 3,800,000
Amount company is liable for per occurrence $ 500,000  
Number of reporting units | reporting_unit 1 5
Minimum    
Summary Of Accounting Policies [Line Items]    
Amount company is liable for per occurrence $ 100,000  
Stop-loss insurance purchased 100,000  
Maximum    
Summary Of Accounting Policies [Line Items]    
Amount company is liable for per occurrence 500,000  
Stop-loss insurance purchased $ 160,000  
Alabama, Florida, Georgia, North Carolina And South Carolina    
Summary Of Accounting Policies [Line Items]    
Number of states | state 4