Debt and Other Obligations - Schedule of Long-Term Obligations (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
Debt Instrument [Line Items]
Total variable rate debt	$ 99	$ 90
Total Medium Term Notes	23	53
Debt	1,026
Total debt	927	657
Capital lease obligations, due through fiscal 2033	12	11
Unamortized debt issuance costs and debt discount	(7)	(4)
Total debt	1,031	754
Less current portion of long-term debt	(7)	(35)
Total long-term debt	1,024	719
Revolving Credit Facility - Canada, expires fiscal 2021 [Member]
Debt Instrument [Line Items]
Line of credit	43	90
Revolving Credit Facility - Euro, expires fiscal 2024 [Member]
Debt Instrument [Line Items]
Line of credit	56
Notes matured fiscal 2019, 7.42% [Member]
Debt Instrument [Line Items]
Total Medium Term Notes		30
3.7% Notes due fiscal 2022 [Member]
Debt Instrument [Line Items]
Notes	350	350
3.4% Notes due fiscal 2026 [Member]
Debt Instrument [Line Items]
Notes	250	250
Notes due fiscal 2022, 8.34% - 8.47% [Member]
Debt Instrument [Line Items]
Total Medium Term Notes	15	15
Notes due fiscal 2028, 6.57% - 7.28% [Member]
Debt Instrument [Line Items]
Total Medium Term Notes	8	8
4.0% Notes due fiscal 2029 [Member]
Debt Instrument [Line Items]
Notes	300
Chinese Renminbi Debt, Due Fiscal 2020, 4.35% [Member]
Debt Instrument [Line Items]
Debt	$ 4
Chinese Renminbi Debt, Matured Fiscal 2019, 4.35% [Member]
Debt Instrument [Line Items]
Debt		$ 4

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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