Other Non-Current Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Prepaid Expenses and Other Assets [Line Items]
Non-current income tax receivable (See Note 19—Income Taxes)		$ 627
Pension assets (See Note 10—Pension, Postretirement and Other Benefits)	$ 22	36
Other investments (See Note 4—Fair Value Measurements and Investments)	46	45
Long-term prepaid operating expenses and other	72	57
Non-current deferred tax assets (See Note 19—Income Taxes)(1)	22	13
Total	893	778
Other Assets
Prepaid Expenses and Other Assets [Line Items]
Non-current income tax receivable (See Note 19—Income Taxes)	$ 731	$ 627