Organization and Summary of Significant Accounting Policies - VIE (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Variable Interest Entity [Line Items]
Current assets	$ 4,133	$ 4,086
Total assets	8,954	9,351	$ 9,424
Current liabilities	3,687	3,678
Noncurrent liabilities	3,109	3,139
Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Current assets	304	285
Noncurrent assets	94	98
Total assets	398	383
Current liabilities	257	241
Noncurrent liabilities	10	12
Total liabilities	$ 267	$ 253