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Note 15 - Merom Acquisition - Summary of Acquired Assets and Liabilities (Details) - USD ($) $ in Thousands | Oct. 21, 2022 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | --- | ---
Plant |  | $ 488,634 | $ 480,462 |
Coal inventory |  | 23,075 | 49,796 |
Amount attributable to assets acquired |  | 589,780 | 630,554 |
Asset retirement obligations |  | 16,688 | 20,834 | $ 14,125
Amount attributable to liabilities assumed |  | $ 321,192 | $ 415,530 |
Merom Acquisition [Member] |  |  |  |
Direct transaction costs | $ 2,855 |  |  |
Contract liability - PPA | 184,500 |  |  |
Contract liability - Capacity payment reduction | 11,000 |  |  |
Contract asset - Coal purchase agreement | (34,300) |  |  |
Coal inventory purchased | 5,400 |  |  |
Deferred coal inventory payment | 11,600 |  |  |
Total consideration | 181,055 |  |  |
Plant | 165,816 |  |  |
Materials and supplies | 12,009 |  |  |
Coal inventory | 10,460 |  |  |
Amount attributable to assets acquired | 188,285 |  |  |
Asset retirement obligations | 7,230 |  |  |
Amount attributable to liabilities assumed | $ 7,230 |  |  |

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