v3.19.1

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Info on Level 3 (Details) - USD ($) | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Derivative, Fair Value, Net | [1] | $ (36,000,000) | $ (141,000,000)
Power Contracts [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Derivative, Fair Value, Net | [2] | 83,000,000 | 36,000,000
Power Contracts [Member] | Minimum [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Fair Value Inputs Quantitative Information |  | 2.20 | 2.12
Power Contracts [Member] | Maximum [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Fair Value Inputs Quantitative Information |  | 208.95 | 227.98
Natural Gas [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Derivative, Fair Value, Net |  | (4,000,000) | (73,000,000)
Natural Gas [Member] | Minimum [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Fair Value Inputs Quantitative Information |  | 0.03 | 0.75
Natural Gas [Member] | Maximum [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Fair Value Inputs Quantitative Information |  | 10.00 | 8.87
Power Congestion Products [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Derivative, Fair Value, Net |  | 23,000,000 | 26,000,000
Power Congestion Products [Member] | Minimum [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Fair Value Inputs Quantitative Information |  | (6.48) | (11.71)
Power Congestion Products [Member] | Maximum [Member] |  |  |
Fair Value Measurements Inputs and Valuation Techniques |  |  |
Fair Value Inputs Quantitative Information |  | $ 8.24 | $ 11.88
[1] | At March 31, 2019 and December 31, 2018, we had $187 million and $244 million, respectively, of collateral under master netting arrangements that were not offset against our derivative instruments on the Consolidated Condensed Balance Sheets primarily related to initial margin requirements.
[2] | (1)Power contracts include power and heat rate instruments classified as level 3 in the fair value hierarchy.

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- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611 + Details
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