Restructuring - Recorded Restructuring Activities (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Restructuring Cost And Reserve [Line Items]
Restructuring reserve, period expense	$ (5)	$ 5	$ 43	$ 12
Cost of Sales [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring reserve, period expense	(6)	1	31	3
Selling and Administrative Expenses [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring reserve, period expense	$ 1	$ 4	8	$ 9
Research and Technical Expenses [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring reserve, period expense			$ 4