Condensed Consolidated Statements of Income (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating Revenues
Regulated Energy	$ 74,580,000	$ 72,770,000	$ 251,601,000	$ 252,667,000
Unregulated Energy and other	18,046,000	20,630,000	96,029,000	103,435,000
Total Operating Revenues	92,626,000	93,400,000	347,630,000	356,102,000
Operating Expenses
Regulated Energy cost of sales	19,619,000	21,501,000	74,452,000	89,741,000
Unregulated Energy and other cost of sales	5,709,000	9,512,000	36,975,000	49,196,000
Operations	32,623,000	31,449,000	99,596,000	97,723,000
Cost, Maintenance	3,920,000	3,208,000	11,199,000	10,419,000
Settlement Gain	0	0	(130,000)	(130,000)
Cost, Depreciation, Amortization and Depletion	11,219,000	10,487,000	33,612,000	29,739,000
Other taxes	5,178,000	4,364,000	15,282,000	13,446,000
Total Operating Expenses	78,268,000	80,521,000	270,986,000	290,134,000
Operating Income	14,358,000	12,879,000	76,644,000	65,968,000
Other expense, net	(350,000)	(4,000)	(729,000)	(168,000)
Interest charges	5,403,000	4,357,000	16,583,000	11,764,000
Income from Continuing Operations Before Income Taxes	8,605,000	8,518,000	59,332,000	54,036,000
Income Taxes on Continuing Operations	2,360,000	2,428,000	15,355,000	14,918,000
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	6,245,000	6,090,000	43,977,000	39,118,000
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	(624,000)	(552,000)	(1,388,000)	(339,000)
Income from Continuing Operations	$ 5,621,000	$ 5,538,000	$ 42,589,000	$ 38,779,000
Weighted Average Common Shares Outstanding:
Basic (shares)	16,403,776	16,378,545	16,396,646	16,366,608
Diluted (shares)	16,453,867	16,428,439	16,444,231	16,416,255
Basic Earnings Per Share of Common Stock:
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.38	$ 0.37	$ 2.68	$ 2.39
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share	(0.04)	(0.03)	(0.08)	(0.02)
Basic (in dollars per share)	0.34	0.34	2.60	2.37
Earnings Per Share, Diluted [Abstract]
Income (Loss) from Continuing Operations, Per Diluted Share	0.38	0.37	2.67	2.38
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share	(0.04)	(0.03)	(0.08)	(0.02)
Diluted (in dollars per share)	$ 0.34	$ 0.34	$ 2.59	$ 2.36