Financial Information by Segment - Schedule of Income (Loss) from Continuing Operations before Taxes and Equity in Earnings from Affiliated Companies for Unallocated and Other (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Interest expense	$ (13)	$ (13)
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Interest expense	(13)	(13)
Total certain items, pre-tax		(58)
Unallocated corporate costs	(12)	(13)
General unallocated income (expense)	5	5
Less: Equity in earnings of affiliated companies, net of tax	(2)
Income from continuing operations before income taxes and equity in earnings of affiliated companies	$ (22)	$ (79)