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MTPSC (Details 3) - Pending Rate Case [Member] - Montana-Dakota Utilities Co. [Member] - Electric - MTPSC - USD ($) $ in Millions	Feb. 01, 2023	Nov. 04, 2022
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 10.5
Public Utilities, Requested Rate Increase (Decrease), Percentage		15.20%
Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Interim Rate Increase (Decrease), Amount	$ 1.7
Public Utilities, Interim Rate Increase (Decrease), Percentage	2.70%

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Amount of public utility's interim rate increase (decrease) allowed while waiting final decision of regulatory agency.

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Amount of public utility's requested rate increase (decrease) with regulatory agency.

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Percentage of public utility's requested rate increase (decrease) with regulatory agency.

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