Revenue Recognition from Contracts with Customers (Schedule of Operating Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Regulated Tariff Sales
Residential	$ 17,780	$ 17,892	$ 33,760	$ 33,515
Commercial	3,744	3,771	7,053	6,880
Industrial	2,321	2,689	4,519	5,001
Fire Protection	3,098	3,073	6,111	5,961
Wholesale	3,429	3,680	6,768	6,892
Non-Regulated Contract Operations	2,986	3,781	5,810	7,780
Total Revenue from Contracts with Customers	33,358	34,886	64,021	66,029
Other Regulated Revenues	73	63	131	125
Other Non-Regulated Revenues	100	101	202	202
Inter-segment Elimination	(138)	(131)	(264)	(260)
Total Revenue	$ 33,393	$ 34,919	$ 64,090	$ 66,096