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NDPSC (Details 2) - Electric - NDPSC [Member] - Montana-Dakota Utilities Co. [Member] - USD ($)
Nov. 01, 2022
Jul. 14, 2022
May 16, 2022
Public Utilities, General Disclosures [Line Items]      
Public Utilities, Interim Rate Increase (Decrease), Amount   $ 10,900,000  
Public Utilities, Interim Rate Increase (Decrease), Percentage   5.30%  
Subsequent Event [Member]      
Public Utilities, General Disclosures [Line Items]      
Total Transmission Cost Adjustment Rider $ 12,900,000    
Public Utilities, Approved Rate Increase (Decrease), Amount (1,600,000)    
Pending Rate Case [Member]      
Public Utilities, General Disclosures [Line Items]      
Public Utilities, Requested Rate Increase (Decrease), Amount     $ 25,400,000
Public Utilities, Requested Rate Increase (Decrease), Percentage     12.30%
Pending Rate Case [Member] | Subsequent Event [Member]      
Public Utilities, General Disclosures [Line Items]      
Public Utilities, Requested Rate Increase (Decrease), Amount (127,000)    
Renewable Resource Cost Adjustment Rate Tariff $ 17,900,000