v3.19.3.a.u2

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Information about Level 3 Fair Value Measurements (Details) - USD ($) | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Derivative, Fair Value, Net | [1] | $ 114,000,000 | $ (141,000,000)
Physical Power [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Derivative, Fair Value, Net | [2] | 158,000,000 | 36,000,000
Physical Power [Member] | Minimum [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 4.85 | 2.12
Physical Power [Member] | Maximum [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 184.15 | 227.98
Natural Gas [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Derivative, Fair Value, Net |  | (20,000,000) | (73,000,000)
Natural Gas [Member] | Minimum [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 1.73 | 0.75
Natural Gas [Member] | Maximum [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | 6.45 | 8.87
Power Congestion Products [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Derivative, Fair Value, Net |  | 17,000,000 | 26,000,000
Power Congestion Products [Member] | Minimum [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | (10.32) | (11.71)
Power Congestion Products [Member] | Maximum [Member] |  |  |
Quantitative Information about Level 3 fair Value Measurements [Line Items] |  |  |
Fair Value Inputs Quantitative Information |  | $ 20.00 | $ 11.88
[1] | At December 31, 2019 and 2018, we had $191 million and $244 million of collateral under master netting arrangements that were not offset against our derivative instruments on the Consolidated Balance Sheets primarily related to initial margin requirements.
[2] | 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=118260190&loc=d3e13433-108611 + Details
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