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Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified		3 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2012	Sep. 30, 2013 Massachusetts	Sep. 30, 2013 Federal	Dec. 31, 2012 Federal and State	Dec. 31, 2012 State and Local Jurisdiction	Dec. 31, 2012 Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net operating loss	$ 19.3
Net operating loss carryforward assets				15.4
NOL carryforward assets expiration date					2019	2029
Alternative Minimum tax credit carryforwards	$ 1.5
Corporate effective tax rate		8.00%
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, 2010; December 31, 2011; and December 31, 2012

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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