Earnings Per Share: (Details) - shares	3 Months Ended
Mar. 27, 2021	Mar. 28, 2020
Earnings Per Share:
Denominator for basic EPS - weighted average common shares	3,736,676	3,711,597
Dilutive shares associated with option plans	137,551	200,154
Denominator for diluted EPS - weighted average common shares and dilutive potential common shares	3,874,227	3,911,751
Options excluded from EPS calculation - anti-dilutive (in shares)	6,987	2,192

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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- References

No definition available.

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- Definition

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.

+ References

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-Publisher FASB
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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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