Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
US income before taxes	$ 1,030,000,000	$ 4,650,000,000	$ 3,973,000,000
U.S. federal statutory rate	35.00%	35.00%	35.00%
Provision for legal matters	4,100,000,000	7,000,000	(45,000,000)
Income taxes receivable included in prepaid and other current assets	179,000,000	112,000,000
Income taxes payable included in accrued taxes as part of accrued liabilities	58,000,000	63,000,000
Accrued income taxes included in other long-term liabilities	171,000,000	468,000,000
Cumulative undistributed earnings of the Company's international subsidiaries intended to be reinvested indefinitely outside the U.S	2,600,000,000
Decreased Singapore tax as a result of the tax incentive agreement	(130,000,000)	(111,000,000)	(93,000,000)
Benefit of the tax incentive agreement on diluted net income per share	$ 0.19	$ 0.16	$ 0.13
Total unrecognized tax benefits exclusive of interest and penalties	679,000,000	850,000,000	545,000,000
Unrecognized tax benefits, if recognized, would reduce the effective tax rate in a future period	537,000,000	696,000,000
Interest expense included in interest expense and administrative and other	45,000,000	7,000,000	37,000,000
Reversal of penalties upon the effective settlement of uncertainties surrounding the timing of certain deductions	1,000,000	2,000,000
Penalties included in interest expense and administrative and other			5,000,000
Accrued interest related to uncertain tax positions in other long term liabilities	20,000,000	65,000,000
Accrued penalties related to uncertain tax positions in other long term liabilities	7,000,000	8,000,000
Unrecognized Tax Benefits, Period Increase (Decrease)	425,000,000
Non United States Customers
US income before taxes	1,600,000,000	1,300,000,000	1,100,000,000
Federal
Net operating loss carryforwards	20,000,000
Research and development tax credit carryforwards	4,000,000
Alternative minimum tax credits	1,000,000
State and Local Jurisdiction
Net operating loss carryforwards	116,000,000
Research and development tax credit carryforwards	19,000,000
Foreign Country
Net operating loss carryforwards	$ 70,000,000