Employee Benefit Plans - Change in Benefit Obligations and Change in Plan Assets (Detail) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Change in Benefit Obligations:
Settlements or curtailment gain		$ (17)
Change in Plan Assets:
Fair value of plan assets at beginning of year		555
Fair value of plan assets at end of year		432	$ 555
U.S. Pension Benefits [Member]
Change in Benefit Obligations:
Benefit obligation at beginning of year		173	170
Service cost		1	2	$ 6
Interest cost		7	7	6
Loss (gain) from changes in actuarial assumptions and plan experience		3	6
Benefits paid	[1]	(13)	(11)
Other		(1)	(1)
Benefit obligation at end of year		170	173	170
Change in Plan Assets:
Fair value of plan assets at beginning of year		167	155
Service cost		1	2	6
Interest cost		7	7	6
Actual return on plan assets		(1)	21
Employer contribution		1	3
Loss (gain) from changes in actuarial assumptions and plan experience		3	6
Benefits paid	[1]	(13)	(11)
Expenses paid from assets		(1)	(1)
Fair value of plan assets at end of year		153	167	155
Funded status		(17)	(6)
Recognized liability		(17)	(6)
Foreign Pension Benefits [Member]
Change in Benefit Obligations:
Benefit obligation at beginning of year		491	439
Service cost		9	9	9
Interest cost		11	16	15
Plan participants’ contribution		2	2
Foreign currency exchange rate changes		(45)	(28)
Loss (gain) from changes in actuarial assumptions and plan experience		(23)	75
Benefits paid	[1]	(13)	(18)
Settlements or curtailment gain	[2]	(85)	(7)
Acquisition / business combination			3
Other		1
Benefit obligation at end of year		348	491	439
Change in Plan Assets:
Fair value of plan assets at beginning of year		388	375
Service cost		9	9	9
Interest cost		11	16	15
Plan participants’ contribution		2	2
Actual return on plan assets		11	41
Employer contribution		10	12
Plan participants’ contribution		2	2
Foreign currency exchange rate changes		(34)	(20)
Loss (gain) from changes in actuarial assumptions and plan experience		(23)	75
Benefits paid	[1]	(13)	(18)
Settlements	[2]	(85)	(4)
Acquisition / business combination			1
Expenses paid from assets			(1)
Fair value of plan assets at end of year		279	388	375
Funded status		(69)	(103)
Recognized liability		(69)	(103)
U. S. Postretirement Benefits [Member]
Change in Benefit Obligations:
Benefit obligation at beginning of year		50	55
Interest cost		2	2	2
Loss (gain) from changes in actuarial assumptions and plan experience		1	(3)
Benefits paid	[1]	(4)	(4)
Plan amendments		(11)
Benefit obligation at end of year		38	50	55
Change in Plan Assets:
Interest cost		2	2	2
Employer contribution		4	4
Loss (gain) from changes in actuarial assumptions and plan experience		1	(3)
Benefits paid	[1]	(4)	(4)
Funded status		(38)	(50)
Recognized liability		(38)	(50)
Foreign Postretirement Benefits [Member]
Change in Benefit Obligations:
Benefit obligation at beginning of year		17	17
Interest cost		1	1	1
Foreign currency exchange rate changes		(2)
Loss (gain) from changes in actuarial assumptions and plan experience		(1)
Benefits paid	[1]		(1)
Benefit obligation at end of year		15	17	17
Change in Plan Assets:
Interest cost		1	1	$ 1
Employer contribution			1
Loss (gain) from changes in actuarial assumptions and plan experience		(1)
Benefits paid	[1]		(1)
Funded status		(15)	(17)
Recognized liability		$ (15)	$ (17)

[1] Included in this amount are $6 million and $7 million that the Company paid directly to the participants in its defined benefit plans in fiscal 2015 and 2014, respectively

[2] The $85 million settlement amount is primarily driven by the transfer of certain plan assets and obligations to a third party, as discussed further under Curtailments and Settlements of Employee Benefit Plans.