CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Operating Revenues	$ 29,102	$ 27,401	$ 56,140	$ 50,947
Operating Expenses:
Operations and Maintenance	15,148	14,765	30,578	29,140
Depreciation	2,725	2,582	5,434	5,130
Other Taxes	3,058	2,844	6,092	5,590
Total Operating Expenses	20,931	20,191	42,104	39,860
Operating Income	8,171	7,210	14,036	11,087
Other Income (Expense):
Allowance for Funds Used During Construction	89	137	127	273
Other Income		125	97	317
Other Expense	(11)	(11)	(21)	(151)
Total Other Income, net	78	251	203	439
Interest Charges	1,538	1,779	2,693	3,133
Income before Income Taxes	6,711	5,682	11,546	8,393
Income Taxes	2,230	1,957	3,888	2,861
Net Income	4,481	3,725	7,658	5,532
Preferred Stock Dividend Requirements	51	51	103	103
Earnings Applicable to Common Stock	$ 4,430	$ 3,674	$ 7,555	$ 5,429
Earnings per share of Common Stock:
Basic	$ 0.28	$ 0.23	$ 0.48	$ 0.35
Diluted	$ 0.28	$ 0.23	$ 0.47	$ 0.35
Average Number of Common Shares Outstanding:
Basic	15,829,000	15,716,000	15,818,000	15,704,000
Diluted	16,092,000	15,979,000	16,081,000	15,967,000
Cash Dividends Paid per Common Share	$ 0.1875	$ 0.1850	$ 0.3750	$ 0.3700