Debt and Other Obligations - Schedule of Long-Term Obligations (Detail) - USD ($) $ in Millions		Sep. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Total Medium Term Notes		$ 53	$ 53
Debt		908
Total debt		908	907
Capital lease obligations, due through 2033		13	13
Unamortized debt issuance costs and debt discount	[1]	(4)	(5)
Total debt		917	915
Less current portion of long-term debt		(256)	(1)
Total long-term debt		661	914
2.55% Notes Due 2018 [Member]
Debt Instrument [Line Items]
Notes		250	250
3.7% Notes Due 2022 [Member]
Debt Instrument [Line Items]
Notes		350	350
3.4% Notes Due 2026 [Member]
Debt Instrument [Line Items]
Notes		250	250
Notes Due 2019, 7.42% [Member]
Debt Instrument [Line Items]
Total Medium Term Notes		30	30
Notes Due 2022, 8.34% - 8.47% [Member]
Debt Instrument [Line Items]
Total Medium Term Notes		15	15
Notes Due 2028, 6.57%-7.28% [Member]
Debt Instrument [Line Items]
Total Medium Term Notes		8	8
Chinese Renminbi Debt, Due 2018, 4.75% [Member]
Debt Instrument [Line Items]
Debt		$ 5	$ 4

[1] In fiscal 2017, the Company adopted a new accounting standard that impacts the presentation of debt issuance costs on the Consolidated Balance Sheets. This new standard was applied retrospectively and fiscal 2016 balances have been updated as discussed in Note A.