Long-Term Debt (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Debt Instrument [Line Items]
Long-term debt	$ 4,347	$ 4,603
Less: Current maturities	560	279
Total, net	3,787	4,324
Long-term debt maturing during year two	268
Long-term debt maturing during year three	520
Long-term debt maturing during year four	250
Long-term debt maturing during year five	250
Interest paid related to short-term borrowings and long-term debt	234	239	264
5.75% Notes Due November 2011 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	November 2011	November 2011
Long-term debt	0	250
Notes interest rate, percentage	5.75%	5.75%
4.625% Notes Due October 2012 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	October 2012	October 2012
Long-term debt	250	250
Notes interest rate, percentage	4.625%	4.625%
4.5% Notes Due May 2013 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	May 2013	May 2013
Long-term debt	250	250
Notes interest rate, percentage	4.50%	4.50%
5.625% Notes Due November 2013 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	November 2013	November 2013
Long-term debt	250	250
Notes interest rate, percentage	5.625%	5.625%
5.0% Notes Due December 2014 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	December 2014	December 2014
Long-term debt	250	250
Notes interest rate, percentage	5.00%	5.00%
4.125% Notes Due April 2015 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	April 2015	April 2015
Long-term debt	250	250
Notes interest rate, percentage	4.125%	4.125%
4.75% Notes Due October 2015 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	October 2015	October 2015
Long-term debt	250	250
Notes interest rate, percentage	4.75%	4.75%
5.125% Notes Due December 2016 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	December 2016	December 2016
Long-term debt	250	250
Notes interest rate, percentage	5.125%	5.125%
5.375% Notes Due October 2017 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	October 2017	October 2017
Long-term debt	250	250
Notes interest rate, percentage	5.375%	5.375%
5.25% Notes Due October 2018[Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	October 2018	October 2018
Long-term debt	400	400
Notes interest rate, percentage	5.25%	5.25%
5.0% Notes Due April 2019 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	April 2019	April 2019
Long-term debt	250	250
Notes interest rate, percentage	5.00%	5.00%
4.875% Notes Due October 2019 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	October 2019	October 2019
Long-term debt	500	500
Notes interest rate, percentage	4.875%	4.875%
4.25% Notes Due November 2020 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	November 2020	November 2020
Long-term debt	300	300
Notes interest rate, percentage	4.25%	4.25%
6.0% Notes Due August 2032 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	August 2032	August 2032
Long-term debt	250	250
Notes interest rate, percentage	6.00%	6.00%
6.125% Notes Due April 2039 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	April 2039	April 2039
Long-term debt	250	250
Notes interest rate, percentage	6.125%	6.125%
5.25% Notes Due November 2039 [Member]
Debt Instrument [Line Items]
Debt Instruments Maturity Date	November 2039	November 2039
Long-term debt	300	300
Notes interest rate, percentage	5.25%	5.25%
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Long-term debt	$ 97	$ 103

Debt instruments maturity date.

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- Definition

Interest rate stated in the contractual debt agreement.

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The amount of cash paid for interest during the period.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year.

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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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