Income Taxes (Schedule of Income Tax Expense Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax at Statutory Rate	$ 6,457	$ 7,009	$ 11,868
Tax Effect of:
Utility Plant Related	(802)	422	(1,016)
Tangible Property Repairs	(10,156)	(7,763)
State Income Taxes - Net	1,173	1,207	895
Tax Act			(610)
Other	188	49	(37)
Total Income Tax Expense	$ (3,140)	$ 924	$ 11,100