Employee Benefit Plans - Net Periodic Defined Benefit Pension and Other Postretirement Benefit Costs (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
U.S. Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2	$ 1	$ 3	$ 3
Expected return on plan assets	(3)	(2)	(6)	(5)
Net periodic (credit) benefit cost	(1)	(1)	(3)	(2)
Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	4	5
Interest cost	2	3	4	6
Expected return on plan assets	(4)	(4)	(7)	(8)
Amortization of actuarial loss	1	1	2	2
Settlement and curtailment cost (credit)				18
Net periodic (credit) benefit cost	1	3	3	23
U. S. Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		1		1
Amortization of prior service credit	(1)		(2)	$ (1)
Settlement and curtailment cost (credit)			(1)
Net periodic (credit) benefit cost	$ (1)	$ 1	$ (3)