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. 31, 2016	$ 29,146,622	$ (19,105,723)	$ 95,631,216	$ (23,204,601)	$ 82,467,514
Balances (in shares) at Dec. 31, 2016	8,950,827	(2,694,729)
Net income			5,045,255		5,045,255
Cash dividends declared			(2,754,568)		(2,754,568)
Currency translation adjustment				1,221,888	1,221,888
Change in fair value of interest rate swap				41,757	41,757
Change in pension and other postretirement benefit costs, net of tax				554,243	554,243
Issuance of SARS	$ 172,806				172,806
Issuance of Common Stock for directors' fees	$ 181,695				181,695
Issuance of Common Stock for directors' fees (in shares)	7,147
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)