Regulatory Matters (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) territory	Sep. 30, 2021 USD ($)
Public Utilities, General Disclosures [Line Items]
U.S. federal statutory rate	4.50%
Increase in revenue requirement	$ 251,000
Authorized return on equity	9.80%
Authorized return on debt	10.30%
Number of original jurisdiction cities | territory	209
Regulatory Assets	$ 37,000	$ 35,000
Percentage of Equity in Current Capital Structure	42.50%
Percentage of Debt in Current Capital Structure	57.50%
Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Percentage of Equity in Current Capital Structure	45.00%
Percentage of Debt in Current Capital Structure	42.50%
Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Percentage of Equity in Current Capital Structure	55.00%
Percentage of Debt in Current Capital Structure	57.50%