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Federal Income Taxes - Additional Information (Detail) (USD $) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2013 | Dec. 31, 2011 | Dec. 31, 2012
Income Tax Disclosure [Abstract] |  |  |
Gross federal net operating loss | $ 11,900,000 |  |
Start expiry date | 2030 |  |
End expiry date | 2031 |  |
General business tax credits | 500,000 |  |
Expiry date | 2028 |  |
Expiry end date | 2033 |  |
Federal alternative minimum tax credits with an indefinite life | 900,000 |  |
Net operating loss relates to unrealized excess benefits | 300,000 |  |
Reversal of valuation allowance against net deferred tax asset |  | 27,400,000 |
Reversal of valuation allowance against net deferred tax asset resulting from 2011 pre-tax income |  | 2,200,000 |
Unrecognized tax benefits | 0 |  | 0
Accruals of any interest or penalties | $ 0 |  | $ 0

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