Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies - Additional Information (Detail)

v3.10.0.1
Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Sep. 30, 2018
USD ($)
reporting_unit
Sep. 30, 2017
USD ($)
May 31, 2018
USD ($)
Summary Of Accounting Policies [Line Items]      
Revisions in estimates related to amounts recorded in prior periods for revenue $ 6,900,000 $ 4,600,000  
Capitalized equity issuance costs   $ 2,200,000  
Amount reclassified from prepaid expense to additional paid-in capital     $ 6,300,000
Amount company is liable for per occurrence $ 500,000    
Number of reporting units | reporting_unit 5    
Minimum      
Summary Of Accounting Policies [Line Items]      
Amount company is liable for per occurrence $ 100,000    
Stop-loss insurance purchased 75,000    
Maximum      
Summary Of Accounting Policies [Line Items]      
Amount company is liable for per occurrence 500,000    
Stop-loss insurance purchased $ 160,000