Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 13
Interest cost	9	11
Expected return on assets	(18)	(17)
Amortization of:
Prior service credit	0	(1)
Actuarial loss	4	2
Curtailment gain	0	(8)
Settlement loss	2	0
Total net periodic benefit cost	(3)	0
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	0	0
Expected return on assets	0	0
Amortization of:
Prior service credit	(1)	(1)
Actuarial loss	0	0
Curtailment gain	0	0
Settlement loss	0	0
Total net periodic benefit cost	(1)	$ (1)
Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2
Interest cost	3
Expected return on assets	(4)
Amortization of:
Prior service credit	0
Actuarial loss	0
Settlement loss	0
Total net periodic benefit cost	$ 1