v3.8.0.1

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Info on Level 3 (Details) - USD ($) | Sep. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Derivative, Fair Value, Net | [1] | $ 274,000,000 | $ 234,000,000
Power Contracts [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Derivative, Fair Value, Net |  | 234,000,000 | 376,000,000
Power Contracts [Member] | Minimum [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 6.55 | 9.60
Power Contracts [Member] | Maximum [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 89.83 | 86.34
Natural Gas [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Derivative, Fair Value, Net |  | 38,000,000 | 18,000,000
Natural Gas [Member] | Minimum [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 0.97 | 1.95
Natural Gas [Member] | Maximum [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 9.35 | 5.66
Power Congestion Products [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Derivative, Fair Value, Net |  | 10,000,000 | 12,000,000
Power Congestion Products [Member] | Minimum [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | (13.13) | (7.52)
Power Congestion Products [Member] | Maximum [Member] |  |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | $ 6.85 | $ 13.62
[1] | At September 30, 2017 and December 31, 2016, we had $115 million and $262 million of collateral under master netting arrangements that were not offset against our derivative instruments on the Consolidated Condensed Balance Sheets.

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