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DERIVATIVE INSTRUMENTS - GAINS (LOSSES) AND NOTIONAL VOLUMES (Details) MWh in Millions, MMBTU in Millions, $ in Millions | 3 Months Ended | 9 Months Ended
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Sep. 30, 2023 USD ($) MMBTU MWh | Sep. 30, 2022 USD ($) MWh MMBTU | Sep. 30, 2023 USD ($) MMBTU MWh | Sep. 30, 2022 USD ($) MWh MMBTU
Realized gains and losses |  |  |  |
Gains (losses) | $ (34.4) | $ 126.5 | $ (174.3) | $ 272.3
Natural gas contracts |  |  |  |
Realized gains and losses |  |  |  |
Gains (losses) | $ (56.3) | $ 119.1 | $ (200.7) | $ 259.6
Notional sales volumes |  |  |  |
Notional sales volumes | MMBTU | 37.8 | 32.7 | 144.2 | 133.3
FTRs and TCRs |  |  |  |
Realized gains and losses |  |  |  |
Gains (losses) | $ 21.9 | $ 7.4 | $ 26.4 | $ 12.7
Notional sales volumes |  |  |  |
Notional sales volumes | MWh | 8.1 | 7.0 | 22.9 | 21.0
Non-Utility Energy Infrastructure |  |  |  |
Realized gains and losses |  |  |  |
Realized gains and losses on derivatives income statement location | Total operating revenues | Total operating revenues | 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 | 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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