Income Taxes - Difference Between Total Income Taxes Expense and Amount Computed at Statutory Federal Income Tax Rate (Detail) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Book income (loss) before income taxes of the TRS	$ (4,261)	$ 974	$ 2,384
Statutory rate of 34% applied to pre-tax income	(1,449)	331	810
Effect of state and local income taxes, net of federal tax benefit	(108)	38	97
Tax reform impact	644	0	0
Provision to return adjustment	5	(406)	211
Permanent adjustments	13	16	140
Change in valuation allowance	1,289	(299)	(998)
Other	2	19	0
Total tax (expense) benefit	$ 396	$ (301)	$ 260
Effective tax rate	(9.29%)	(30.90%)	10.91%