Derivative Instruments and Hedging Activities Location and Fair Values of Derivative Instruments and Hedging Activities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Designated as Hedging Instrument
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	$ 39	$ 34
Derivatives Liabilities under ASC 815	1,403	874
Designated as Hedging Instrument | Other current assets | Foreign currency exchange derivatives
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	19	14
Designated as Hedging Instrument | Other current assets | Commodity derivatives
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	8	11
Designated as Hedging Instrument | Other current assets | Interest rate swaps
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	2	2
Designated as Hedging Instrument | Other current assets | Cross-currency interest rate swaps
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	7	1
Designated as Hedging Instrument | Other noncurrent assets | Interest rate swaps
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	3	6
Designated as Hedging Instrument | Other noncurrent assets | Equity swap
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	0	0
Designated as Hedging Instrument | Other current liabilities | Foreign currency exchange derivatives
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	21	17
Designated as Hedging Instrument | Other current liabilities | Commodity derivatives
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	3	0
Designated as Hedging Instrument | Current portion of long-term debt | Fixed rate debt swapped to floating
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	452	401
Designated as Hedging Instrument | Long-term debt | Fixed rate debt swapped to floating
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	927	456
Not Designated as Hedging Instrument
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	197	131
Derivatives Liabilities under ASC 815	11	9
Not Designated as Hedging Instrument | Other current assets | Foreign currency exchange derivatives
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	14	8
Not Designated as Hedging Instrument | Other current assets | Commodity derivatives
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	0	0
Not Designated as Hedging Instrument | Other current assets | Interest rate swaps
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	0	0
Not Designated as Hedging Instrument | Other current assets | Cross-currency interest rate swaps
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	0	0
Not Designated as Hedging Instrument | Other noncurrent assets | Interest rate swaps
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	0	0
Not Designated as Hedging Instrument | Other noncurrent assets | Equity swap
Derivative Instruments [Line Items]
Derivatives Assets under ASC 815	183	123
Not Designated as Hedging Instrument | Other current liabilities | Foreign currency exchange derivatives
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	11	9
Not Designated as Hedging Instrument | Other current liabilities | Commodity derivatives
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	0
Not Designated as Hedging Instrument | Current portion of long-term debt | Fixed rate debt swapped to floating
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	0	0
Not Designated as Hedging Instrument | Long-term debt | Fixed rate debt swapped to floating
Derivative Instruments [Line Items]
Derivatives Liabilities under ASC 815	$ 0	$ 0