SDPUC (Details 2) - SDPUC - Electricity [Member] - Montana-Dakota Utilities Co. [Member] - USD ($)	Apr. 28, 2022	Mar. 01, 2022
Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Total Infrastructure Rider	$ 940,000
Public Utilities, Approved Rate Increase (Decrease), Amount	$ (88,000)
Pending Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Total Transmission Cost Adjustment Rider		$ 2,500,000
Transmission Capital Projects Increase (Decrease)		$ 1,500,000