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Financing: Debt Covenants (Details)	Jun. 30, 2022
Line of Credit Facility [Line Items]
Consolidated Indebtedness to Capitalization Ratio	0.608
Wyoming Electric
Line of Credit Facility [Line Items]
Debt Instrument, Indebtedness To Capitalization Ratio Requirement for the Next Fiscal Year	0.50
Maximum
Line of Credit Facility [Line Items]
Consolidated Indebtedness to Capitalization Ratio	0.65
Maximum | Wyoming Electric
Line of Credit Facility [Line Items]
Debt Instrument, Indebtedness To Capitalization Ratio Requirement for the Next Fiscal Year	0.60

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