MNPUC (Details) - Tax Cuts and Jobs Act [Member] - Subsequent Event [Member] - Natural gas rate proceeding [Member] - MNPUC [Member]	Apr. 18, 2019 USD ($)
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	$ (400,000)
Public Utilities, Approved One-Time Increase (Decrease) to Customers, Amount	$ (400,000)

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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