Regulatory matters - SDPUC (Details) - Natural gas distribution - SDPUC - Subsequent Event - Montana-Dakota Utilities Co. $ in Millions	Oct. 31, 2025 USD ($)
Public Utilities, General Disclosures [Line Items]
Public utilities, interim rate increase (decrease), amount	$ 1.5
Public utilities, annual revenue increase (decrease)	$ 1.1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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