Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Revenues
Regulated Energy	$ 301,902	$ 300,442	$ 264,637
Unregulated Energy	162,108	184,961	166,723
Other businesses and eliminations	(4,766)	13,431	12,946
Total operating revenues	459,244	498,834	444,306
Operating Expenses
Regulated energy cost of sales	122,814	134,560	118,818
Unregulated energy and other cost of sales	97,228	143,556	126,017
Operations	107,562	102,197	91,452
Maintenance	11,803	9,706	7,509
Asset Impairment Charges	(1,500)	6,881	0
Depreciation and amortization	29,972	26,316	23,965
Other taxes	13,607	13,339	13,811
Total operating expenses	381,486	436,555	381,572
Operating Income	77,758	62,279	62,734
Gains from sales of businesses	0	7,139	0
Other income, net of other expenses	293	101	372
Interest charges	10,006	9,482	8,234
Income Before Income Taxes	68,045	60,037	54,872
Income taxes	26,905	23,945	22,085
Net Income	$ 41,140	$ 36,092	$ 32,787
Weighted Average Common Shares Outstanding:
Basic (in shares)	15,094,423	14,551,308	14,430,962
Diluted (in shares)	15,143,373	14,604,944	14,543,446
Earnings Per Share of Common Stock:
Basic (in usd per share)	$ 2.73	$ 2.48	$ 2.27
Diluted (in usd per share)	2.72	2.47	2.26
Cash Dividends Declared Per Share of Common Stock (in usd per share)	$ 1.1325	$ 1.0667	$ 1.0133