XML 74 R47.htm IDEA: XBRL DOCUMENT v3.21.1
Inventories, Net (Details) - USD ($)
$ in Millions
Mar. 31, 2021
Sep. 30, 2020
Inventories, Net    
Materials and supplies inventory $ 767 $ 770
Fuel inventory 263 253
Renewable energy certificates/emission allowance inventory, net 18 15
Allowance for inventory obsolescence (34) (35)
Inventories, net $ 1,014 $ 1,003