XML 72 R87.htm IDEA: XBRL DOCUMENT v3.20.1
Income Taxes (Additional Information) (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2020
Mar. 31, 2019
Sep. 30, 2019
Business Acquisition [Line Items]          
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent 21.00% 21.00% 21.00% 21.00%  
Deferred Income Tax Expense (Benefit)     $ 36.4    
Effective Income Tax Rate Reconciliation, Percent 1139.20% 2.00% (109.60%) (10.70%)  
Deferred Tax Assets, Net         $ 92.6