Income Taxes (Schedule of Net Deferred Tax Liability) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Utility Plant Related	$ 65,107	$ 56,868
Customer Advances	(3,595)	(3,626)
Employee Benefits	7,091	7,339
Investment Tax Credits	373	445
Other	524	271
Total Deferred Tax Liability and ITC	$ 69,500	$ 61,297