Consolidated Statements of Shareholders' Equity - USD ($)	Common Stock [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balances at Jan. 03, 2015	$ 28,932,058	$ (19,105,723)	$ 87,680,667	$ (22,532,095)	$ 74,974,907
Balances (in shares) at Jan. 03, 2015	8,938,742	(2,694,729)
Net income			5,727,043		5,727,043
Cash dividends declared			(2,810,669)		(2,810,669)
Currency translation adjustment				(2,009,277)	(2,009,277)
Change in fair value of interest rate swap					0
Change in pension and other postretirement benefit costs, net of tax				3,458,060	3,458,060
Issuance of Common Stock for directors' fees	$ 64,992				64,992
Issuance of Common Stock for directors' fees (in shares)	3,719
Balances at Jan. 02, 2016	$ 28,997,050	$ (19,105,723)	90,597,041	(21,083,312)	79,405,056
Balances (in shares) at Jan. 02, 2016	8,942,461	(2,694,729)
Net income			7,785,323		7,785,323
Cash dividends declared			(2,751,148)		(2,751,148)
Currency translation adjustment				(1,010,983)	(1,010,983)
Change in fair value of interest rate swap					0
Change in pension and other postretirement benefit costs, net of tax				(1,110,306)	(1,110,306)
Issuance of Common Stock for directors' fees	$ 149,572				149,572
Issuance of Common Stock for directors' fees (in shares)	8,366
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)