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Commitments, Contingencies and Guarantees: Power Sales Agreements (Details) - MW | Jun. 03, 2022 | May 03, 2022
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Wygen I I I Generating Facility |  |
Unrecorded Unconditional Purchase Obligation [Line Items] |  |
Jointly Owned Utility Plant, Proportionate Ownership Share |  | 25.00%
M D U, Montana Dakota Utilities | South Dakota Electric |  |
Unrecorded Unconditional Purchase Obligation [Line Items] |  |
Number of Megawatts Sold Under Long-Term Contract | 23 |
M D U, Montana Dakota Utilities | South Dakota Electric | Maximum |  |
Unrecorded Unconditional Purchase Obligation [Line Items] |  |
Number of Megawatts Sold Under Long-Term Contract |  | 50

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- Definition The proportionate share of interest (percent) in a jointly owned utility plant. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -URI https://asc.fasb.org/extlink&oid=122136288&loc=d3e659983-123033 + Details
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