CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
CONDENSED CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Operating Revenues	$ 31,666	$ 29,190	$ 60,446	$ 56,363
Operating Expenses:
Operations and Maintenance	16,229	14,563	32,317	30,000
Depreciation	2,982	2,837	5,930	5,652
Other Taxes	3,220	3,043	6,280	5,997
Total Operating Expenses	22,431	20,443	44,527	41,649
Operating Income	9,235	8,747	15,919	14,714
Other Income (Expense):
Allowance for Funds Used During Construction	103	66	185	133
Other Income	43	135	82	146
Other Expense	(18)	(155)	(83)	(175)
Total Other Income, net	128	46	184	104
Interest Charges	1,496	1,515	2,554	2,618
Income before Income Taxes	7,867	7,278	13,549	12,200
Income Taxes	2,778	2,550	4,825	4,303
Net Income	5,089	4,728	8,724	7,897
Preferred Stock Dividend Requirements	36	36	72	79
Earnings Applicable to Common Stock	$ 5,053	$ 4,692	$ 8,652	$ 7,818
Earnings per share of Common Stock:
Basic (in dollars per share)	$ 0.31	$ 0.29	$ 0.54	$ 0.49
Diluted (in dollars per share)	$ 0.31	$ 0.29	$ 0.53	$ 0.49
Average Number of Common Shares Outstanding :
Basic (in shares)	16,149	16,018	16,141	15,996
Diluted (in shares)	16,305	16,199	16,297	16,190
Cash Dividends Paid per Common Share (in dollars per share)	$ 0.1925	$ 0.1900	$ 0.3850	$ 0.3800