Financial Information by Segment & Geographic Area - Sales of Equity Method Affiliate and Discounting Charges for Certain Notes Receivable (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Net sales	$ 619	$ 621	$ 568	$ 603	$ 671	$ 694	$ 694	$ 812	$ 2,411	$ 2,871	$ 3,647
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Net sales									101	99	104
Unallocated and Other [Member] | Royalties, Other Operating Revenues, the Impact of Unearned Revenue, the Removal of 100% of the Sales of an Equity Method Affiliate and Discounting Charges for Certain Notes Receivable [Member]
Segment Reporting Information [Line Items]
Net sales									13	9	(7)
Unallocated and Other [Member] | Shipping and Handling Costs [Member]
Segment Reporting Information [Line Items]
Net sales									$ 88	$ 90	$ 111