XML 23 R7.htm IDEA: XBRL DOCUMENT v3.20.2
Consolidated Statement of Cash Flows (Parenthetical) - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2018
Statement of Cash Flows [Abstract]      
Purchase accounting amortization $ 3 $ 4 $ 22