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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, 2024 USD ($) MWh MMBTU | Mar. 31, 2023 USD ($) MWh MMBTU
Realized gains and losses |  |
Gains (losses) | $ (55.3) | $ (74.9)
Natural gas contracts |  |
Realized gains and losses |  |
Gains (losses) | $ (56.9) | $ (75.3)
Notional sales volumes |  |
Notional sales volumes | MMBTU | 67.8 | 58.7
FTRs and TCRs |  |
Realized gains and losses |  |
Gains (losses) | $ 1.6 | $ 0.4
Notional sales volumes |  |
Notional sales volumes | MWh | 7.6 | 7.3
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 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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