Amounts from Accumulated Other Comprehensive Income to be Amortized into Net Periodic Benefit Cost (Detail) $ in Millions	12 Months Ended
	Sep. 30, 2016 USD ($)
U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial loss (gain)	$ 15
Prior service credit	0
Total	15
U.S. Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial loss (gain)	(1)
Prior service credit	(2)
Total	(3)
Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial loss (gain)	2
Prior service credit	0
Total	$ 2