v3.3.1.900

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Information about Level 3 Fair Value Measurements (Details) - USD ($) | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Derivative, Fair Value, Net | $ (196,000,000) | $ 271,000,000
Physical Power [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Derivative, Fair Value, Net | (54,000,000) | 74,000,000
Physical Power [Member] | Minimum [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Fair Value Inputs Quantitative Information | 6.72 | 14.00
Physical Power [Member] | Maximum [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Fair Value Inputs Quantitative Information | $ 83.25 | 122.79
Natural Gas [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Derivative, Fair Value, Net |  | 5,000,000
Natural Gas [Member] | Minimum [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Fair Value Inputs Quantitative Information |  | 1
Natural Gas [Member] | Maximum [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Fair Value Inputs Quantitative Information |  | 10.86
Power Congestion Products [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Derivative, Fair Value, Net | $ 8,000,000 | 9,000,000
Power Congestion Products [Member] | Minimum [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Fair Value Inputs Quantitative Information | (11.47) | (19.56)
Power Congestion Products [Member] | Maximum [Member] |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |
Fair Value Inputs Quantitative Information | $ 12.19 | $ 19.56

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