Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Operating loss carryforwards	$ 11,200,000
Deferred tax assets, valuation allowance	0
Uncertain tax positions	0	$ 0	$ 0
Recognized interest income, net of Federal income tax expense	9,000	11,000	$ 465,000
Amount of accrued interest or penalties	$ 0	$ 0