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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. |  |

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