Income Taxes, Continuing Operations - Deferred Tax Assets and Liabilities (Detail) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Gross deferred tax liabilities:
Property having a financial statement basis in excess of tax basis	$ 365,000	$ 364,000
Insurance premiums and accrued leasing revenues	31,000	25,000
Gross deferred tax liabilities	396,000	389,000
Less deferred tax assets	(90,000)	(51,000)
Deferred tax liabilities, net of deferred tax assets	$ 306,000	$ 338,000