Net Income per Share (Details)	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Net Income per Share [Abstract]
Weighted average common shares outstanding - basic (in shares)	7,946,462	7,939,165
Potential shares exercisable under stock option plans (in shares)	517,000	463,500
LESS: Shares which could be repurchased under treasury stock method (in shares)	(203,229)	(186,601)
Weighted average common shares outstanding - diluted (in shares)	8,260,233	8,216,064

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of equity unit purchase agreements using the treasury stock method.

+ References+ Details

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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- Definition

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.

+ References

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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+ Details