v3.4.0.3

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Info on Level 3 (Details) - USD ($) | Mar. 31, 2016 | Dec. 31, 2015
--- | --- | ---
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Derivative, Fair Value, Net | $ (287,000,000) | $ (196,000,000)
Power Contracts [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Derivative, Fair Value, Net | (77,000,000) | (54,000,000)
Power Contracts [Member] | Minimum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information | 4.95 | 6.72
Power Contracts [Member] | Maximum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information | 100.54 | $ 83.25
Natural Gas [Member] | Minimum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information |  |
Natural Gas [Member] | Maximum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information |  |
Power Congestion Products [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Derivative, Fair Value, Net | 12,000,000 | $ 8,000,000
Power Congestion Products [Member] | Minimum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information | (11.33) | (11.47)
Power Congestion Products [Member] | Maximum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information | $ 10.38 | $ 12.19

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