Net Deferred Tax Assets and Liabilities Included in the Consolidated Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Tax Credit Carryforward [Line Items]
Deferred Tax Assets, Valuation Allowance	$ (25)	$ (13)
Current deferred tax assets	481	2,027
Non current deferred tax liabilities	(4,149)	(4,058)
Net deferred tax (liabilities) assets	(3,668)	(2,031)
Federal
Tax Credit Carryforward [Line Items]
Research and development tax credit carryforwards	2
Foreign Country
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	$ 115