Consolidated Statements of Shareholders' Equity - USD ($)	Common Stock [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balances at Dec. 30, 2017	$ 29,501,123	$ (19,105,723)	$ 97,921,903	$ (21,386,713)	$ 86,930,590
Balances (in shares) at Dec. 30, 2017	8,957,974	(2,694,729)
Net income			14,505,937		14,505,937
Cash dividends declared			(2,756,478)		(2,756,478)
Currency translation adjustment				(1,163,136)	(1,163,136)
Change in fair value of interest rate swap				124,687	124,687
Change in pension and other postretirement benefit costs, net of tax				(203,353)	(203,353)
Treasury stock purchases		$ (1,063,375)			(1,063,375)
Treasury stock purchases (in shares)		(40,000)
Issuance of SARS	$ 276,777				276,777
Issuance of SARS (in shares)	151
Issuance of Common Stock for directors' fees	$ 216,990				216,990
Issuance of Common Stock for directors' fees (in shares)	7,862
Balances at Dec. 29, 2018	$ 29,994,890	$ (20,169,098)	109,671,362	(22,628,515)	96,868,639
Balances (in shares) at Dec. 29, 2018	8,965,987	(2,734,729)
Net income			13,266,142		13,266,142
Cash dividends declared			(2,748,393)		(2,748,393)
Currency translation adjustment				68,377	68,377
Change in fair value of interest rate swap				574	574
Change in pension and other postretirement benefit costs, net of tax				(2,675,007)	(2,675,007)
Issuance of SARS	$ 397,250				397,250
Issuance of SARS (in shares)	151
Issuance of Common Stock for directors' fees	$ 259,675				259,675
Issuance of Common Stock for directors' fees (in shares)	9,296
Balances at Dec. 28, 2019	$ 30,651,815	$ (20,169,098)	$ 120,189,111	$ (25,234,571)	$ 105,437,257
Balances (in shares) at Dec. 28, 2019	8,975,434	(2,734,729)