XML 68 R58.htm IDEA: XBRL DOCUMENT v3.21.2
Debt - Other Debt and Other Items (Details) - Other Debt - Standby letter of credit - Unsecured - USD ($)
$ in Millions
Jun. 30, 2021
Sep. 30, 2020
Debt    
Outstanding letters of credit $ 489.6 $ 510.1
Current borrowing capacity $ 443.1