|
Derivative and Financial Instruments - Commodity Balance Sheet (Details) (USD $)
In Millions, unless otherwise specified |
Sep. 30, 2012
|
Sep. 30, 2011
|
|---|---|---|
|
Prepaid expenses and other current assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Commodity derivative assets | $ 2,429 | $ 4,433 |
|
Other assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Commodity derivative assets | 188 | 415 |
|
Other accruals [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Commodity derivative liabilities | 2,389 | 4,350 |
|
Other liabilities and deferred credits [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Commodity derivative liabilities | $ 189 | $ 374 |