v2.4.0.6

Derivative Instruments (Details 2) (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2011 | Dec. 31, 2010
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |
Current derivative assets | $ 1,051 | $ 725
Long-term derivative assets | 113 | 170
Total derivative assets | 1,164 | 895
Current derivative liabilities | 1,144 | 718
Long-term derivative liabilities | 279 | 370
Total derivative liabilities | 1,423 | 1,088
Net derivative assets (liabilities) | (259) | (193)
Fair Value of Derivative Assets | 1,164 | 895
Fair Value of Derivative Liabilities | 1,423 | 1,088
Designated as Hedging Instrument [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value of Derivative Assets | 61 | 163
Fair Value of Derivative Liabilities | 167 | 195
Not Designated as Hedging Instrument [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value of Derivative Assets | 1,103 | 732
Fair Value of Derivative Liabilities | 1,256 | 893
Interest Rate Swap [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Current derivative assets | 0 | 0
Long-term derivative assets | 10 | 4
Total derivative assets | 10 | 4
Current derivative liabilities | 166 | 197
Long-term derivative liabilities | 154 | 174
Total derivative liabilities | 320 | 371
Net derivative assets (liabilities) | (310) | (367)
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value of Derivative Assets | 10 | 2
Fair Value of Derivative Liabilities | 149 | 143
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value of Derivative Assets | 0 | 2
Fair Value of Derivative Liabilities | 171 | 228
Commodity Option [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Current derivative assets | 1,051 | 725
Long-term derivative assets | 103 | 166
Total derivative assets | 1,154 | 891
Current derivative liabilities | 978 | 521
Long-term derivative liabilities | 125 | 196
Total derivative liabilities | 1,103 | 717
Net derivative assets (liabilities) | 51 | 174
Commodity Option [Member] | Designated as Hedging Instrument [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value of Derivative Assets | 51 | 161
Fair Value of Derivative Liabilities | 18 | 52
Commodity Option [Member] | Not Designated as Hedging Instrument [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value of Derivative Assets | 1,103 | 730
Fair Value of Derivative Liabilities | $ 1,085 | $ 665

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