Income Taxes - Components of Income Tax Expense (Benefit) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Current Federal alternative minimum tax ("AMT") expense	$ 147,000	$ 303,000	$ 92,000
Current state and local tax expense	40,000	662,000	254,000
Deferred Federal tax expense	1,704,000	4,962,000	2,118,000
Deferred state and local tax expense (benefit)	62,000	(513,000)	(4,000)
Consolidated income tax expense, including taxes attributable to discontinued operations	1,953,000	5,414,000	2,460,000
Less income tax expense (benefit) attributable to discontinued operations	0	1,409,000	(382,000)
Income tax expense	1,953,000	4,005,000	2,842,000
Consolidated income tax expense, including taxes attributable to discontinued operations	$ 1,953,000	$ 5,414,000	$ 2,460,000