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DERIVATIVE INSTRUMENTS - GAINS (LOSSES) AND NOTIONAL VOLUMES (Details) MWh in Millions, MMBTU in Millions, $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2026 USD ($) MWh MMBTU | Jun. 30, 2025 USD ($) MWh MMBTU | Jun. 30, 2026 USD ($) MWh MMBTU | Jun. 30, 2025 USD ($) MWh MMBTU
Realized gains and losses |  |  |  |
Gains (losses) | $ (12.5) | $ 9.8 | $ 18.9 | $ 9.4
Natural gas contracts | Utility operations |  |  |  |
Realized gains and losses |  |  |  |
Gains (losses) | $ (16.8) | $ 6.5 | $ 12.8 | $ 4.6
Realized gains and losses on derivatives income statement location | Cost of sales | Cost of sales | Cost of sales | Cost of sales
Notional volumes |  |  |  |
Notional volumes | MMBTU | 48.6 | 47.3 | 111.6 | 108.8
FTRs and TCRs | Non-Utility Energy Infrastructure |  |  |  |
Realized gains and losses |  |  |  |
Gains (losses) | $ 0.0 | $ 0.3 | $ 0.1 | $ 0.1
Realized gains and losses on derivatives income statement location | Total operating revenues | Total operating revenues | Total operating revenues | Total operating revenues
Notional volumes |  |  |  |
Notional volumes | MWh | 0.0 | 0.3 | 0.1 | 0.6
FTRs and TCRs | Utility operations |  |  |  |
Realized gains and losses |  |  |  |
Gains (losses) | $ 4.3 | $ 3.0 | $ 6.0 | $ 4.7
Realized gains and losses on derivatives income statement location | Cost of sales | Cost of sales | Cost of sales | Cost of sales
Notional volumes |  |  |  |
Notional volumes | MWh | 6.1 | 6.7 | 11.9 | 13.8

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