Federal Income Taxes - Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal tax provision (benefit) at statutory tax rate	$ (1,225)	$ (538)	$ 343
TRS state and local taxes, net of Federal benefit	(190)	(84)	53
Permanent differences, net	1,131	1,663	396
Prior year (over) under-accrual, net	(1,541)	0	938
Effect of Tax Cuts and Jobs Act	1,982	0	0
Other	404	(1,516)	(131)
REIT state and local income and franchise taxes	443	370	188
Total provision (benefit) for income taxes	$ 1,004	$ (105)	$ 1,787