Public utilities interim rate increase (decrease), revised

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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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No definition available.

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Percentage 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 amended requested rate increase (decrease) with regulatory agency.

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

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

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No definition available.

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

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Montana Public Service Commission (MTPSC) (Details 2) - MTPSC - Natural gas rate proceeding - USD ($)	Apr. 24, 2018	Feb. 23, 2018	Jan. 12, 2018	Sep. 25, 2017
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease), amount		$ 2,800,000		$ 2,800,000
Public utilities, requested rate increase (decrease), percentage				4.10%
Public utilities, interim rate increase (decrease), amount				$ 1,600,000
Public utilities, interim rate increase (decrease), percentage				2.30%
Tax Cuts and Jobs Act
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease), amended, amount		$ 1,600,000
Public utilities interm rate increase (decrese) revised			$ 764,000
Subsequent Event \| Tax Cuts and Jobs Act
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease), amended, amount	$ 975,000
Public utilities, requested rate increase (decrease), amended, percentage	1.40%