Derivative Financial Instruments (Schedule Of Derivative Financial Instruments Included In The Consolidated Balance Sheets And Consolidated Statement Of Operations) (Details) (USD $) In Millions | 3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2011 | Sep. 30, 2010 | Dec. 31, 2010 | |
| Fair value of derivative assets | $ 916 | $ 916 | $ 389 | ||
| Fair value of derivative liabilities | 58 | 58 | 192 | ||
| Total cash settlements | 170 | 249 | 336 | 617 | |
| Total unrealized gains (losses) | 587 | (95) | 661 | 136 | |
| Net gain (loss) recognized on statement of operations | 757 | 154 | 997 | 753 | |
Commodity Derivatives [Member] | |||||
| Total cash settlements | 96 | 232 | 241 | 580 | |
| Total unrealized gains (losses) | 642 | (23) | 745 | 294 | |
Commodity Derivatives [Member] | Other Current Assets [Member] | |||||
| Fair value of derivative assets | 672 | 672 | 248 | ||
Commodity Derivatives [Member] | Other Long-Term Assets [Member] | |||||
| Fair value of derivative assets | 188 | 188 | 1 | ||
Commodity Derivatives [Member] | Other Current Liabilities [Member] | |||||
| Fair value of derivative liabilities | 38 | 38 | 50 | ||
Commodity Derivatives [Member] | Other Long-Term Liabilities [Member] | |||||
| Fair value of derivative liabilities | 20 | 20 | 142 | ||
Interest Rate Derivatives [Member] | |||||
| Total cash settlements | 52 | 17 | 73 | 37 | |
| Total unrealized gains (losses) | (55) | (72) | (84) | (158) | |
Interest Rate Derivatives [Member] | Other Current Assets [Member] | |||||
| Fair value of derivative assets | 29 | 29 | 100 | ||
Interest Rate Derivatives [Member] | Other Long-Term Assets [Member] | |||||
| Fair value of derivative assets | 27 | 27 | 40 | ||
Foreign Currency Derivatives [Member] | |||||
| Total cash settlements | $ 22 | $ 22 | |||