Employee Benefit Plans - Net Amounts Recognized in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	$ (173)	$ (138)
U.S. Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities		(1)
Noncurrent liabilities	(18)	(16)
Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	8	5
Current liabilities	(1)	(1)
Noncurrent liabilities	(102)	(73)
U. S. Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(3)	(4)
Noncurrent liabilities	(34)	(34)
Foreign Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(1)
Noncurrent liabilities	$ (19)	$ (15)