CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Operating Revenues	$ 33,393	$ 34,919	$ 64,090	$ 66,096
Operating Expenses:
Operations and Maintenance	16,781	16,825	32,901	34,659
Depreciation	4,123	3,736	8,170	7,345
Other Taxes	3,539	3,637	7,042	7,021
Total Operating Expenses	24,443	24,198	48,113	49,025
Operating Income	8,950	10,721	15,977	17,071
Other Income (Expense):
Allowance for Funds Used During Construction	643	214	1,158	381
Other Income (Expense), net	(80)	571	(138)	868
Total Other Income, net	563	785	1,020	1,249
Interest Charges	1,788	2,068	2,988	3,206
Income before Income Taxes	7,725	9,438	14,009	15,114
Income Taxes	(421)	763	(687)	1,945
Net Income	8,146	8,675	14,696	13,169
Preferred Stock Dividend Requirements	36	36	72	72
Earnings Applicable to Common Stock	$ 8,110	$ 8,639	$ 14,624	$ 13,097
Earnings per share of Common Stock:
Basic	$ 0.49	$ 0.53	$ 0.89	$ 0.80
Diluted	$ 0.49	$ 0.52	$ 0.88	$ 0.80
Average Number of Common Shares Outstanding:
Basic	16,519	16,388	16,474	16,371
Diluted	16,675	16,544	16,630	16,527
Cash Dividends Paid per Common Share	$ 0.2400	$ 0.2238	$ 0.4800	$ 0.4475