Components of Net Periodic Benefit Cost (Detail) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	8	9	24	27
Expected return on plan assets	(17)	(17)	(52)	(52)
Amortization of actuarial loss	0	3	0	11
Settlement loss	3	9	3	22
Total net periodic benefit cost	(6)	4	(25)	8
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	3	5
Interest cost	3	3	9	8
Expected return on plan assets	(5)	(4)	(15)	(12)
Amortization of actuarial loss	0	0	0	1
Settlement loss	0	0	0	0
Total net periodic benefit cost	$ (1)	$ 1	$ (3)	$ 2