Schedule of Power Cost Adjustment Mechanism (Details) - Subsidiaries [Member] $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Regulatory Assets [Line Items]
Annual Power Cost Variability, Interest	$ 1.7	$ 2.0
Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount	68.0	76.1
Customer's share | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount	$ 36.7	44.0
Customer's share | Range 1 | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0
Customer's share | Range 1 | Over-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0
Customer's share | Range 2 | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.50
Customer's share | Range 2 | Over-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.65
Customer's share | Range 3 | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.90
Customer's share | Range 3 | Over-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.90
Companys share | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount		$ 32.1
Companys share | Range 1 | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	1
Companys share | Range 1 | Over-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	1
Companys share | Range 2 | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.50
Companys share | Range 2 | Over-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.35
Companys share | Range 3 | Under-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.10
Companys share | Range 3 | Over-collection
Regulatory Assets [Line Items]
Annual Power Cost Variability	0.10