CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($)	3 Months Ended
Mar. 30, 2019	Mar. 31, 2018
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Net income	$ 1,570,960	$ 3,100,195
Other comprehensive income (loss):
Change in foreign currency translation	412,624	608,928
Change in pension and postretirement benefit costs, net of tax expense of: 2019 - $70,938 and 2018 - $65,842	222,681	222,725
Change in fair value of marketable securities, net of tax benefit of: 2019 - $3,471 and 2018 - $0	(10,639)	0
Change in fair value of interest rate swap and marketable securities, net of tax benefit of: 2019 - $24,619 and 2018 - ($65,557)	(77,961)	165,840
Total other comprehensive income (loss)	546,705	997,463
Comprehensive income	$ 2,117,665	$ 4,094,688

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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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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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 increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (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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Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

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