Nonconsolidated Partially-Owned Affiliates Summarized Balance Sheet Data (Detail) - Equity Method Investments - USD ($) $ in Millions	Sep. 30, 2018	Sep. 30, 2017
Equity Method Investments, Summarized Balance Sheet Information [Line Items]
Current Assets	$ 4,307	$ 4,034
Noncurrent assets	1,654	1,513
Total assets	5,961	5,547
Current liabilities	2,718	2,470
Noncurrent liabilities	459	478
Noncontrolling interests	39	33
Shareholders' equity	2,745	2,566
Total liabilities and shareholders' equity	$ 5,961	$ 5,547