Organization and Summary of Significant Accounting Policies - Schedule of Carrying Amounts and Classifications of Assets and Liabilities for Consolidated VIEs (Details) - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023
Variable Interest Entity [Line Items]
Current assets	$ 4,125	$ 4,316
Total assets	9,278	9,424
Current liabilities	3,658	3,738
Noncurrent liabilities	3,160	3,083
VIEs
Variable Interest Entity [Line Items]
Current assets	258	265
Noncurrent assets	107	121
Total assets	365	386
Current liabilities	193	228
Noncurrent liabilities	12	13
Total liabilities	$ 205	$ 241