Financial And Derivative Instruments (Details) (USD $) | 3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2011
cubicFeet | Sep. 30, 2010 | Dec. 31, 2010 | |
| Estimated fair value of total long-term debt, including capitalized lease obligations | $ 9,800,000,000 | $ 9,800,000,000 | $ 12,800,000,000 | ||
| Recorded book values of total long-term debt, including capitalized lease obligations | 9,331,000,000 | 9,331,000,000 | 12,227,000,000 | ||
| Derivative assets at fair value, net | 77,000,000 | 77,000,000 | 172,000,000 | ||
| Gain (loss) before-tax earnings impact of derivatives | 32,000,000 | 70,000,000 | 92,000,000 | 103,000,000 | |
| Volume (Cubic feet daily) | 250,000,000 | ||||
| Weighted average NYMEX price (per thousand cubic feet) | $ 7.02 | ||||
Cash Flow Hedge [Member] | |||||
| Derivative assets at fair value, net | 74,000,000 | 74,000,000 | |||
| Gain (loss) before-tax earnings impact of derivatives | $ 84,000,000 | ||||