Income Taxes - Additional Information (Detail) - USD ($)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Operating Loss Carryforwards [Line Items]          
Alternative Minimum tax credit carryforwards         $ 2,100,000
Income tax benefit $ 1,200,000 $ 1,100,000 $ 8,200,000 $ 10,000,000  
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 | Tax Year 2016          
Operating Loss Carryforwards [Line Items]          
Income tax benefit     $ (241,900)    
Internal Revenue Service (IRS)          
Operating Loss Carryforwards [Line Items]          
NOL carryforward assets and Research and Development (R&D) credit carryforwards         $ 11,300,000
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, 2012; December 31, 2013; and December 31, 2014.