Summary of Significant Accounting Policies - Schedule of Cash and Restricted Cash (Details) - USD ($) $ in Millions	Jun. 30, 2023	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 260	$ 405	$ 670
Restricted cash	78	64	14
Cash, cash equivalents and restricted cash	$ 338	$ 469	$ 684	$ 877