Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statements of Income [Abstract]
OPERATING REVENUES	$ 11,644	$ 11,290
OPERATING EXPENSES:
Operation and maintenance	2,354	2,026
Administrative and general	1,995	2,088
Depreciation and amortization	1,841	1,681
Taxes other than income taxes	314	333
Operating expenses	6,504	6,128
Operating income	5,140	5,162
OTHER INCOME (EXPENSES):
Interest on debt	(1,364)	(1,316)
Allowance for funds used during construction	92	123
Other pension costs	(321)	(305)
Other income (expenses), net	(82)	(126)
Other income (expenses)	(1,675)	(1,624)
Income before income taxes	3,465	3,538
Income taxes	871	957
Net Income	$ 2,594	$ 2,581
Basic Earnings Per Share (in dollars per share)	$ 0.20	$ 0.20
Diluted Earnings Per Share (in dollars per share)	0.20	0.20
Cash Dividends Declared Per Share (in dollars per share)	$ 0.1666	$ 0.1602