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Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Alternative Minimum tax credit carryforwards	$ 1,500,000		$ 1,500,000
Income tax benefit	2,000,000	$ 100,000	10,200,000	$ 10,100,000
Federal Research and Development Tax Credit \| Tax Year 2014
Operating Loss Carryforwards [Line Items]
Income tax benefit					$ (63,000)
Federal Research and Development Tax Credit \| Tax Year 2015
Operating Loss Carryforwards [Line Items]
Income tax benefit					$ (288,000)
Federal Research and Development Tax Credit \| 2016 expenditures
Operating Loss Carryforwards [Line Items]
Income tax benefit			(362,852)
Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
NOL carryforward assets and Research and Development (R&D) credit carryforwards	$ 12,200,000		$ 12,200,000
NOL carryforward assets expiration date			2029
R&D credits expiration year			2035
Federal
Operating Loss Carryforwards [Line Items]
Tax examination description			The Company remains subject to examination by Federal, Maine, Massachusetts, and New Hampshire tax authorities for the tax periods ended December 31, 2013; December 31, 2014; and December 31, 2015.