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Risk Management and Derivatives: Cash Flow Hedges (Details) - Cash Flow Hedging - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Interest Rate Swap and Commodity Derivative |  |  |  |
Derivative [Line Items] |  |  |  |
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months |  |  | $ 6,100 |
Designated as Hedging Instrument |  |  |  |
Derivative [Line Items] |  |  |  |
Unrealized Gain (Loss) on Cash Flow Hedging Instruments | $ (3,658) | $ 1,900 | (3,812) | $ 2,786
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net | 610 | (657) | 2,151 | (1,401)
Designated as Hedging Instrument | Interest rate swaps |  |  |  |
Derivative [Line Items] |  |  |  |
Unrealized Gain (Loss) on Cash Flow Hedging Instruments | 713 | 713 | 1,426 | 1,426
Designated as Hedging Instrument | Interest rate swaps | Interest Expense |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion | 713 | 713 | 1,426 | 1,426
Designated as Hedging Instrument | Commodity Contract |  |  |  |
Derivative [Line Items] |  |  |  |
Unrealized Gain (Loss) on Cash Flow Hedging Instruments | (4,371) | 1,187 | (5,238) | 1,360
Designated as Hedging Instrument | Commodity Contract | Fuel, purchased power and cost of natural gas sold |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion | $ 1,323 | $ 56 | $ 3,577 | $ 25

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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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=121549185&loc=d3e80748-113994 + Details
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- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959 + Details
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- Definition The effective portion of gain reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959 + Details
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- Definition The effective portion of loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959 + Details
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