Debt - Schedule of Receivables Facility (Details) - Energy Services - Receivables Facility - Energy Services Receivables Facility - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Short-term Debt [Line Items]
Trade receivables transferred to ESFC during the year	$ 2,221	$ 1,353	$ 1,046
ESFC trade receivables sold to the bank during the year	152	308	182
ESFC trade receivables - end of year	$ 101	61	$ 50
Outstanding balance of trade receivables sold		$ 0