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Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified |  | 12 Months Ended | 6 Months Ended
--- | --- | --- | ---
Dec. 31, 2012 | Dec. 31, 2012 Federal and State | Dec. 31, 2012 State and Local Jurisdiction | Dec. 31, 2012 Internal Revenue Service (IRS) | Jun. 30, 2013 Federal
Operating Loss Carryforwards [Line Items] |  |  |  |  |
Net operating loss carryforward assets |  | $ 8.5 |  |  |
NOL carryforward assets expiration date |  |  | 2019 | 2029 |
Cumulative alternative minimum tax credit carryforwards | $ 1.5 |  |  |  |
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, 2009; December 31, 2010; and December 31, 2011.

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