Per Share Data - Composition of Weighted Average Common Shares Used in Earnings per Share Computation (Details) - shares	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted average common shares issued (in shares)	7,525,561	7,517,280	7,522,803	7,516,406
Weighted average treasury stock shares (in shares)	(480,225)	(480,225)	(480,225)	(480,225)
Weighted average shares outstanding - basic (in shares)	7,045,336	7,037,055	7,042,578	7,036,181
Dilutive effect of outstanding stock options (in shares)	0	0	0	0
Weighted average common shares outstanding - basic and diluted (in shares)	7,045,336	7,037,055	7,042,578	7,036,181

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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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- Definition

Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

+ References

No definition available.

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- Definition

This element represents the weighted average total number of shares issued throughout the period including the first (beginning balance outstanding) and last (ending balance outstanding) day of the period before considering any reductions (for instance, shares held in treasury) to arrive at the weighted average number of shares outstanding. Weighted average relates to the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Such concept is used in determining the weighted average number of shares outstanding for purposes of calculating earnings per share (basic).

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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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- Definition

Number of shares of treasury stock determined by relating the portion of time within a reporting period that treasury shares have been outstanding to the total time in that period. Treasury stock is stock that the Entity has issued but subsequently reacquired.

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