v2.4.0.6

Derivative Instruments (Details 2) (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |  |  |
Current derivative assets | $ 339 |  | $ 1,051 |
Long-term derivative assets | 98 |  | 113 |
Total derivative assets | 437 |  | 1,164 |
Current derivative liabilities | 357 |  | 1,144 |
Long-term derivative liabilities | 293 |  | 279 |
Total derivative liabilities | 650 |  | 1,423 |
Net derivative assets (liabilities) | (213) |  | (259) |
Fair Value of Derivative Assets | 437 |  | 1,164 |
Fair Value of Derivative Liabilities | 650 |  | 1,423 |
Designated as Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value of Derivative Assets | 4 | [1] | 61 | [1]
Fair Value of Derivative Liabilities | 184 | [1] | 167 | [1]
Not Designated as Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value of Derivative Assets | 433 |  | 1,103 |
Fair Value of Derivative Liabilities | 466 |  | 1,256 |
Interest Rate Swap [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Current derivative assets | 0 |  | 0 |
Long-term derivative assets | 4 |  | 10 |
Total derivative assets | 4 |  | 10 |
Current derivative liabilities | 40 |  | 166 |
Long-term derivative liabilities | 160 |  | 154 |
Total derivative liabilities | 200 |  | 320 |
Net derivative assets (liabilities) | (196) |  | (310) |
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value of Derivative Assets | 4 | [1] | 10 | [1]
Fair Value of Derivative Liabilities | 184 | [1] | 149 | [1]
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value of Derivative Assets | 0 |  | 0 |
Fair Value of Derivative Liabilities | 16 |  | 171 |
Commodity Option [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Current derivative assets | 339 |  | 1,051 |
Long-term derivative assets | 94 |  | 103 |
Total derivative assets | 433 |  | 1,154 |
Current derivative liabilities | 317 |  | 978 |
Long-term derivative liabilities | 133 |  | 125 |
Total derivative liabilities | 450 |  | 1,103 |
Net derivative assets (liabilities) | (17) |  | 51 |
Commodity Option [Member] | Designated as Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value of Derivative Assets | 0 | [1] | 51 | [1]
Fair Value of Derivative Liabilities | 0 | [1] | 18 | [1]
Commodity Option [Member] | Not Designated as Hedging Instrument [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value of Derivative Assets | 433 |  | 1,103 |
Fair Value of Derivative Liabilities | $ 450 |  | $ 1,085 |
[1] | Includes accumulated fair value of derivative instruments as of the date hedge accounting was discontinued, net of amortized fair value for settlement periods which have transpired.

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