Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Details)

v3.20.2
Income Taxes - Additional Information (Details) - USD ($)
 3 Months Ended 6 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2020
Mar. 31, 2019
Tax Credit Carryforward [Line Items]        
Income tax rate 26.80% 29.90% 26.70% 27.70%
Uncertain tax positions $ 0   $ 0  
Tax Year 2020 | US        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2020  
Tax Year 2020 | State        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2020  
Tax Year 2019 | US        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2019  
Tax Year 2019 | State        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2019  
Tax Year 2018 | US        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2018  
Tax Year 2018 | State        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2018  
Tax Year 2017 | US        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2017  
Tax Year 2017 | State        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2017  
Tax Year 2016 | State        
Tax Credit Carryforward [Line Items]        
Income tax subject to audit     2016