Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Carrying Amounts and Classifications of Assets and Liabilities for Consolidated VIEs (Details) - USD ($) $ in Millions	Jun. 30, 2022	Sep. 30, 2021
Variable Interest Entity [Line Items]
Current assets	$ 4,062	$ 5,086
Total assets	9,315	10,778
Current liabilities	3,387	3,511
Noncurrent liabilities	3,430	4,309
VIEs
Variable Interest Entity [Line Items]
Current assets	223	158
Noncurrent assets	105	88
Total assets	328	246
Current liabilities	193	143
Noncurrent liabilities	13	8
Total liabilities	$ 206	$ 151