Income Taxes - Components of Income Tax Expense (Benefit) (Parenthetical) (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Deferred Federal AMT expense (benefit)	$ (79,000)	$ (81,000)	$ (141,000)	$ (119,000)