Financial Information by Segment - Royalties Paid by Equity Affiliates, External Shipping and Handling Fees, Impact of Corporate Adjustment for Unearned Revenue and Notes Receivable Reflected by Unallocated and Other (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 812	$ 898
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Net sales	31	28
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	4
Unallocated and Other [Member] | Shipping and Handling Costs [Member]
Segment Reporting Information [Line Items]
Net sales	$ 27	$ 28