Employee Benefit Plans - Change in Benefit Obligations and Change in Plan Assets (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Defined Benefit Plan Disclosure [Line Items]
Increase decrease in pension obligation plans	$ (14)		$ (11)		$ (38)
Accumulated other comprehensive income loss on pension plan, net of tax	(68)		106
Change in Assumptions for Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefits paid	7		7
U.S. Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase decrease in pension obligation plans			(19)
Accumulated other comprehensive income loss on pension plan, net of tax			13
Benefits paid	11	[1]	11	[1]
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's Net periodic benefit cost			$ 1

[1] Included in this amount is $7 million that the Company paid directly to the participants in its defined benefit plans in both fiscal 2014 and 2013.