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SEGMENTS OF BUSINESS - Revenuer Reconciliation (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
SEGMENTS OF BUSINESS |  |  |  |
Other Operating Revenue | $ 2,355 | $ 1,377 | $ 8,780 | $ 3,685
Total sales and operating revenues | 146,846 | 105,155 | 367,522 | 310,774
Delivered Energy |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 77,776 | 56,256 | 194,044 | 148,490
Capacity Revenue |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 15,459 | 15,860 | 45,110 | 44,506
Coal Sales |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 51,256 | 31,662 | 119,588 | 114,093
Coal Sales | Third-Party |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 51,256 | 31,662 | 119,588 | 114,093
Electric Operations |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 93,235 | 72,116 | 239,154 | 192,996
Electric Operations | Delivered Energy |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 77,776 | 56,256 | 194,044 | 148,490
Electric Operations | Capacity Revenue |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 15,459 | 15,860 | 45,110 | 44,506
Coal Operations |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 51,256 | 31,662 | 119,588 | 114,093
Operating Segment | Electric Operations |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Other Operating Revenue | 192 | 187 | 3,413 | 518
Total sales and operating revenues | 93,427 | 72,303 | 242,567 | 193,514
Operating Segment | Electric Operations | Delivered Energy |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 77,776 | 56,256 | 194,044 | 148,490
Operating Segment | Electric Operations | Capacity Revenue |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 15,459 | 15,860 | 45,110 | 44,506
Operating Segment | Coal Operations |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Other Operating Revenue | 1,647 | 721 | 4,370 | 2,028
Total sales and operating revenues | 70,461 | 49,041 | 173,487 | 162,094
Operating Segment | Coal Operations | Coal Sales |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 68,814 | 48,320 | 169,117 | 160,066
Operating Segment | Coal Operations | Coal Sales | Third-Party |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 51,256 | 31,662 | 119,588 | 114,093
Operating Segment | Coal Operations | Coal Sales | Intercompany |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | 17,558 | 16,658 | 49,529 | 45,973
Corporate and Other Eliminations |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Other Operating Revenue | 516 | 469 | 997 | 1,139
Total sales and operating revenues | (17,042) | (16,189) | (48,532) | (44,834)
Corporate and Other Eliminations | Coal Sales | Intercompany |  |  |  |
SEGMENTS OF BUSINESS |  |  |  |
Operating Revenues | $ (17,558) | $ (16,658) | $ (49,529) | $ (45,973)

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