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, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
U.S. Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 1	$ 2	$ 2	$ 3
Expected return on plan assets	(2)	(3)	(5)	(6)
Net periodic benefit (credit) cost	(1)	(1)	(3)	(3)
Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	2	5	4
Interest cost	2	2	3	4
Expected return on plan assets	(4)	(4)	(7)	(7)
Amortization of actuarial loss	2	1	3	2
Net periodic benefit (credit) cost	3	1	4	3
U. S. Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service credit	(1)	(1)	(1)	(2)
Settlement and curtailment cost (credit)				(1)
Net periodic benefit (credit) cost	$ (1)	$ (1)	$ (1)	$ (3)