Summary of Significant Accounting Policies (Reconciliation of Net Income (Loss) Reported in Financial Statements and Federal Tax Return) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Summary of Significant Accounting Policies [Abstract]
Net income per financial statements	$ 1,902	$ 2,808
Adjustment to depreciation expense	217	227
Provision for losses and doubtful accounts	7
Adjustments to revenues / other expenses	3	25
Adjustments to gain on sales of assets	181	396
Income per federal tax return (unaudited)	$ 2,310	$ 3,456