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Risk Management and Derivatives: Cash Flow Hedges (Details) - Cash Flow Hedging - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Interest rate swaps |  |  |  |
Derivative [Line Items] |  |  |  |
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months |  |  | $ 4.5 |
Designated as Hedging Instrument |  |  |  |
Derivative [Line Items] |  |  |  |
Unrealized Gain (Loss) on Cash Flow Hedging Instruments | $ (0.9) | $ 0.9 | 0.8 | $ 5.3
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net | (0.8) | (0.8) | (2.6) | (5.4)
Designated as Hedging Instrument | Interest rate swaps |  |  |  |
Derivative [Line Items] |  |  |  |
Unrealized Gain (Loss) on Cash Flow Hedging Instruments | 0.7 | 0.8 | 2.1 | 2.2
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion | (0.7) | (0.8) | (2.1) | (2.2)
Designated as Hedging Instrument | Commodity Contract |  |  |  |
Derivative [Line Items] |  |  |  |
Unrealized Gain (Loss) on Cash Flow Hedging Instruments | (1.6) | 0.1 | (1.3) | 3.1
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion | $ (0.1) | $ (0.0) | $ (0.5) | $ (3.2)

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- Definition Derivative instruments losses reclassified from accumulated OCI into income effective portion. + References No definition available. + Details
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- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480870/815-30-50-1 + Details
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