Risk & Uncertainties (Details)	3 Months Ended
	Jun. 30, 2020
Residential Revenue
Unusual Risk or Uncertainty [Line Items]
Percentage of kWh Increase/Decrease	8.50%
Residential Revenue | Subsidiaries [Member]
Unusual Risk or Uncertainty [Line Items]
Percentage of kWh Increase/Decrease	8.50%
Commercial Revenue
Unusual Risk or Uncertainty [Line Items]
Percentage of kWh Increase/Decrease	11.00%
Commercial Revenue | Subsidiaries [Member]
Unusual Risk or Uncertainty [Line Items]
Percentage of kWh Increase/Decrease	11.00%
Industrial Revenue
Unusual Risk or Uncertainty [Line Items]
Percentage of kWh Increase/Decrease	19.90%
Industrial Revenue | Subsidiaries [Member]
Unusual Risk or Uncertainty [Line Items]
Percentage of kWh Increase/Decrease	19.90%