Fair Value Measurements Assets and Liabilities Measured at Fair Value (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	$ 243	$ 236
Gross amount, derivative liabilities	1,813	1,414
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	247	266
Total liabilities	1,813	1,414
Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	34	33
Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	33	32
Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		8
Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	3	3
Interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		2
Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	2	3
Interest rate swaps | Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	3
Cross-currency interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	15	7
Equity swap | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	192	183
Fixed rate debt swapped to floating | Current portion of long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	125	452
Fixed rate debt swapped to floating | Long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	1,649	927
Quoted Prices in Active Markets (Level 1) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	196	213
Total liabilities	0	0
Quoted Prices in Active Markets (Level 1) | Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Quoted Prices in Active Markets (Level 1) | Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Quoted Prices in Active Markets (Level 1) | Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0
Quoted Prices in Active Markets (Level 1) | Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Quoted Prices in Active Markets (Level 1) | Interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0
Quoted Prices in Active Markets (Level 1) | Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Quoted Prices in Active Markets (Level 1) | Interest rate swaps | Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0
Quoted Prices in Active Markets (Level 1) | Cross-currency interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Quoted Prices in Active Markets (Level 1) | Equity swap | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	192	183
Quoted Prices in Active Markets (Level 1) | Fixed rate debt swapped to floating | Current portion of long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Quoted Prices in Active Markets (Level 1) | Fixed rate debt swapped to floating | Long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	51	53
Total liabilities	1,813	1,414
Significant Other Observable Inputs (Level 2) | Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	34	33
Significant Other Observable Inputs (Level 2) | Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	33	32
Significant Other Observable Inputs (Level 2) | Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		8
Significant Other Observable Inputs (Level 2) | Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	3	3
Significant Other Observable Inputs (Level 2) | Interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		2
Significant Other Observable Inputs (Level 2) | Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	2	3
Significant Other Observable Inputs (Level 2) | Interest rate swaps | Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	3
Significant Other Observable Inputs (Level 2) | Cross-currency interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	15	7
Significant Other Observable Inputs (Level 2) | Equity swap | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Significant Other Observable Inputs (Level 2) | Fixed rate debt swapped to floating | Current portion of long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	125	452
Significant Other Observable Inputs (Level 2) | Fixed rate debt swapped to floating | Long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	1,649	927
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Total liabilities	0	0
Significant Unobservable Inputs (Level 3) | Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Significant Unobservable Inputs (Level 3) | Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Significant Unobservable Inputs (Level 3) | Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0
Significant Unobservable Inputs (Level 3) | Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Significant Unobservable Inputs (Level 3) | Interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0
Significant Unobservable Inputs (Level 3) | Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Significant Unobservable Inputs (Level 3) | Interest rate swaps | Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0
Significant Unobservable Inputs (Level 3) | Cross-currency interest rate swaps | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Significant Unobservable Inputs (Level 3) | Equity swap | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	0	0
Significant Unobservable Inputs (Level 3) | Fixed rate debt swapped to floating | Current portion of long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Significant Unobservable Inputs (Level 3) | Fixed rate debt swapped to floating | Long-term debt | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities	0	0
Available-for-sale Securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	4	30
Available-for-sale Securities [Member] | Quoted Prices in Active Markets (Level 1) | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	4	30
Available-for-sale Securities [Member] | Significant Other Observable Inputs (Level 2) | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	0	0
Available-for-sale Securities [Member] | Significant Unobservable Inputs (Level 3) | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	$ 0	$ 0