Nonconsolidated Partially-Owned Affiliates Summarized Income Statement Data (Detail) - Equity Method Investments - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Equity Method Investments, Summarized Income Statement Information [Line Items]
Net sales	$ 6,445	$ 5,329	$ 3,527
Gross profit	1,510	1,323	718
Net income	517	415	195
Income attributable to noncontrolling interests	11	16	0
Net income attributable to the entity	$ 506	$ 399	$ 195