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Acquisitions, Investments and Dispositions - Upton 2 (Details) - Con Edison Development $ in Millions | 1 Months Ended | 12 Months Ended
--- | --- | ---
May 31, 2017 USD ($) | Dec. 31, 2019 MW
Upton 2 |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |
Generating capacity (MW AC) | MW |  | 180
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Upton 2 |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |
Consideration the project is sold | $ 11.0 |
Gain on sale of project | 1.0 |
Gain on sale of project, net of tax | $ 0.7 |

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