Income Taxes - Components of Income Tax Expense (Benefit) (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Current Federal alternative minimum tax ("AMT") expense	$ 79,000	$ 81,000	$ 141,000	$ 119,000
Current state and local tax expense	99,000	96,000	160,000	96,000
Deferred Federal tax expense	434,000	1,738,000	1,245,000	2,360,000
Deferred state and local tax expense (benefit)	(32,000)	(559,000)	21,000	(472,000)
Consolidated income tax expense, including taxes attributable to discontinued operations	580,000	1,356,000	1,567,000	2,103,000
Less income tax expense attributable to discontinued operations		755,000		708,000
Income tax expense	580,000	601,000	1,567,000	1,395,000
Consolidated income tax expense, including taxes attributable to discontinued operations	$ 580,000	$ 1,356,000	$ 1,567,000	$ 2,103,000