CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($)	3 Months Ended
Mar. 28, 2020	Mar. 30, 2019
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Net income	$ 2,895,817	$ 1,570,960
Other comprehensive income (loss):
Change in foreign currency translation	(1,304,447)	412,624
Change in pension and postretirement benefit costs, net of tax expense of: 2020 - $81,143 and 2019 - $70,938	260,295	222,681
Change in fair value of marketable securities, net of tax benefit of: 2020 - $2,897 and 2019 - $3,471	8,878	(10,639)
Change in fair value of interest rate swap and marketable securities, net of tax benefit of: 2020 - $535,029 and 2019 - $24,619	(1,697,793)	(77,961)
Total other comprehensive income (loss)	(2,733,067)	546,705
Comprehensive income	$ 162,750	$ 2,117,665

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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