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DERIVATIVE INSTRUMENTS - GAINS (LOSSES) AND NOTIONAL VOLUMES (Details) MWh in Millions, MMBTU in Millions, $ in Millions | 3 Months Ended
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Mar. 31, 2025 USD ($) MWh MMBTU | Mar. 31, 2024 USD ($) MMBTU MWh
Realized gains and losses |  |
Gains (losses) | $ (0.4) | $ (55.3)
Natural gas contracts |  |
Realized gains and losses |  |
Gains (losses) | $ (1.9) | $ (56.9)
Notional sales volumes |  |
Notional sales volumes | MMBTU | 61.5 | 67.8
FTRs and TCRs |  |
Realized gains and losses |  |
Gains (losses) | $ 1.5 | $ 1.6
Notional sales volumes |  |
Notional sales volumes | MWh | 7.4 | 7.6
Non-Utility Energy Infrastructure |  |
Realized gains and losses |  |
Realized gains and losses on derivatives income statement location | Total operating revenues | Total operating revenues
Utility operations |  |
Realized gains and losses |  |
Realized gains and losses on derivatives income statement location | Cost of sales | Cost of sales

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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4A -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A + Details
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- Definition Indicates line item in statement of income or comprehensive income that includes gain (loss) from derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4A -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A + Details
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