Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Revenues
Regulated Energy	$ 300,442	$ 264,637	$ 246,208
Unregulated Energy	184,961	166,723	133,049
Other	13,431	12,946	13,245
Total operating revenues	498,834	444,306	392,502
Operating Expenses
Regulated energy cost of sales	134,560	118,818	111,402
Unregulated energy and other cost of sales	143,556	126,017	101,957
Operations	102,197	91,452	82,387
Maintenance	9,706	7,509	7,423
Asset Impairment Charges	6,881	0	0
Depreciation and amortization	26,316	23,965	22,510
Other taxes	13,339	13,811	10,188
Total operating expenses	436,555	381,572	335,867
Operating Income	62,279	62,734	56,635
Gain (Loss) on Disposition of Business	7,139
Other income, net of other expenses	101	372	271
Interest charges	9,482	8,234	8,747
Income Before Income Taxes	60,037	54,872	48,159
Income taxes	23,945	22,085	19,296
Net Income	$ 36,092	$ 32,787	$ 28,863
Weighted Average Common Shares Outstanding:
Basic (in shares)	14,551,308	14,430,962	14,379,216
Diluted (in shares)	14,604,944	14,543,446	14,507,261
Earnings Per Share of Common Stock:
Basic (in usd per share)	$ 2.48	$ 2.27	$ 2.01
Diluted (in usd per share)	$ 2.47	$ 2.26	$ 1.99
Cash Dividends Declared Per Share of Common Stock (in usd per share)	$ 1.067	$ 1.013	$ 0.96