CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Operating Revenues	$ 36,701	$ 35,277	$ 69,242	$ 67,046
Operating Expenses:
Operations and Maintenance	17,959	17,620	36,315	34,812
Depreciation	5,187	4,629	10,019	9,077
Other Taxes	3,741	3,643	7,460	7,245
Total Operating Expenses	26,887	25,892	53,794	51,134
Operating Income	9,814	9,385	15,448	15,912
Other Income (Expense):
Allowance for Funds Used During Construction	768	795	2,031	1,917
Other Income (Expense), net	790	334	1,564	720
Total Other Income, net	1,558	1,129	3,595	2,637
Interest Charges	2,070	1,946	3,808	3,615
Income before Income Taxes	9,302	8,568	15,235	14,934
Income Taxes	(1,621)	(1,145)	(2,593)	(2,447)
Net Income	10,923	9,713	17,828	17,381
Preferred Stock Dividend Requirements	30	30	60	60
Earnings Applicable to Common Stock	$ 10,893	$ 9,683	$ 17,768	$ 17,321
Earnings per share of Common Stock:
Basic	$ 0.62	$ 0.55	$ 1.02	$ 0.99
Diluted	$ 0.62	$ 0.55	$ 1.01	$ 0.99
Average Number of Common Shares Outstanding :
Basic	17,488	17,462	17,482	17,449
Diluted	17,603	17,577	17,597	17,564