CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
CONDENSED CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Operating Revenues	$ 34,654	$ 32,669	$ 95,100	$ 89,032
Operating Expenses:
Operations and Maintenance	16,772	14,956	49,089	44,957
Depreciation	3,032	2,880	8,962	8,532
Other Taxes	3,390	3,213	9,671	9,210
Total Operating Expenses	23,194	21,049	67,722	62,699
Operating Income	11,460	11,620	27,378	26,333
Other Income (Expense):
Allowance for Funds Used During Construction	113	80	297	213
Other Income (Expense), net	108	5	108	(23)
Total Other Income, net	221	85	405	190
Interest Charges	1,505	1,516	4,058	4,134
Income before Income Taxes	10,176	10,189	23,725	22,389
Income Taxes	3,433	3,431	8,258	7,735
Net Income	6,743	6,758	15,467	14,654
Preferred Stock Dividend Requirements	36	36	108	115
Earnings Applicable to Common Stock	$ 6,707	$ 6,722	$ 15,359	$ 14,539
Earnings per share of Common Stock:
Basic (in dollars per share)	$ 0.41	$ 0.42	$ 0.95	$ 0.91
Diluted (in dollars per share)	$ 0.41	$ 0.42	$ 0.95	$ 0.90
Average Number of Common Shares Outstanding :
Basic (in shares)	16,202	16,097	16,161	16,030
Diluted (in shares)	16,358	16,253	16,317	16,211
Cash Dividends Paid per Common Share (in dollars per share)	$ 0.1925	$ 0.1900	$ 0.5775	$ 0.5700