Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating Revenues
Regulated Energy	$ 82,762	$ 74,580	$ 259,235	$ 251,601
Unregulated Energy and other	18,657	18,046	91,925	96,029
Total Operating Revenues	101,419	92,626	351,160	347,630
Operating Expenses
Regulated Energy cost of sales	16,271	19,619	67,490	74,452
Unregulated Energy and other cost of sales	5,640	5,709	30,250	36,975
Operations	34,959	32,614	105,516	99,558
Maintenance	3,717	3,920	11,695	11,200
Gain from a settlement			(130)	(130)
Depreciation and amortization			42,793	34,049
Depreciation and amortization	18,293	11,220	42,793	33,612
Other taxes	5,133	5,187	16,028	15,318
Total Operating Expenses	84,013	78,269	273,642	270,985
Operating Income	17,406	14,357	77,518	76,645
Other income (expense), net	(40)	(351)	2,997	(731)
Interest charges	4,584	5,403	15,452	16,583
Income from Continuing Operations Before Income Taxes	12,782	8,603	65,063	59,331
Income Taxes on Continuing Operations	3,502	2,352	16,082	15,354
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	(19)	(630)	165	(1,388)
Net Income (Loss) Attributable to Parent	$ 9,261	$ 5,621	$ 49,146	$ 42,589
Weighted Average Common Shares Outstanding:
Basic (shares)	16,533,748	16,403,776	16,466,106	16,396,646
Diluted (shares)	16,592,842	16,453,867	16,523,200	16,444,231
Basic Earnings Per Share of Common Stock:
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.56	$ 0.38	$ 2.97	$ 2.68
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share	0	(0.04)	0.01	(0.08)
Basic (in dollars per share)	0.56	0.34	2.98	2.60
Earnings Per Share, Diluted [Abstract]
Income (Loss) from Continuing Operations, Per Diluted Share	0.56	0.38	2.96	2.67
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share	0	(0.04)	0.01	(0.08)
Diluted (in dollars per share)	$ 0.56	$ 0.34	$ 2.97	$ 2.59
Retained Earnings [Member]
Operating Expenses
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	$ 9,280	$ 6,251	$ 48,981	$ 43,977
Net Income (Loss) Attributable to Parent	$ 9,261	$ 5,621	$ 49,146	$ 42,589