Income Taxes (Schedule of Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (4,281)	$ (3,822)	$ (188)
State	2,598	2,246	2,073
Deferred:
Federal	(1,490)	(726)	(338)
State	(871)	(761)	(545)
Investment Tax Credits	(75)	(77)	(78)
Total Income Tax (Benefit) Expense	$ (4,119)	$ (3,140)	$ 924