Income Per Share - Computation of Basic and Diluted Net Income (Loss) Per Share (Detail) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Net income (loss) available to common shareholders:
Basic net income available to common shareholders from continuing operations	$ 2,708,000	$ 2,708,000
Basic net loss available to common shareholders from discontinued operations	(162,000)	(181,000)
Diluted net income available to common shareholders from continuing operations	2,708,000	2,708,000
Diluted net loss available to common shareholders from discontinued operations	$ (162,000)	$ (181,000)
Shares:
Basic weighted average number of common shares outstanding	4,093,000	4,128,000
Common shares assumed upon exercise of stock options	67,000	33,000
Diluted weighted average number of common shares outstanding	4,160,000	4,161,000
Basic net income (loss) per common share:
Income from continuing operations	$ 0.66	$ 0.65
(Loss) from discontinued operations, net of tax	$ (0.04)	$ (0.04)
Net income	$ 0.62us-gaap_EarningsPerShareBasic	$ 0.61us-gaap_EarningsPerShareBasic
Diluted net income (loss) per common share:
Income from continuing operations	$ 0.65	$ 0.65
(Loss) from discontinued operations, net of tax	$ (0.04)	$ (0.04)
Net income	$ 0.61us-gaap_EarningsPerShareDiluted	$ 0.61us-gaap_EarningsPerShareDiluted

Net Income Loss From Discontinuing Operations Available To Common Stockholders Diluted

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Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation.

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Per diluted share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from a disposal group, net of income tax, reported as a separate component of income before extraordinary items after deduction or consideration of the amount allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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