Income Taxes (Schedule of Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ (3,822)	$ (188)	$ 2,090
State	2,246	2,073	1,066
Deferred:
Federal	(726)	(338)	7,713
State	(761)	(545)	310
Investment Tax Credits	(77)	(78)	(79)
Total Income Tax Expense	$ (3,140)	$ 924	$ 11,100