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, 2011	$ 28,499,779	$ (19,105,723)	$ 73,200,362	$ (13,436,090)	$ 69,158,328
Balances (in shares) at Dec. 31, 2011	8,908,607	(2,694,729)
Net income			8,625,800		8,625,800
Cash dividends declared			(3,108,577)		(3,108,577)
Miscellaneous			4		4
Currency translation adjustment				533,291	533,291
Change in pension and postretirement benefit costs, net of tax				(3,712,466)	(3,712,466)
Issuance of Common Stock upon the exercise of stock options	61,110				61,110
Issuance of Common Stock upon the exercise of stock options (in shares)	4,500
Tax benefit from exercise of non-qualified stock options and disqualifying dispositions of incentive stock options					0
Issuance of Common Stock for directors' fees	24,609				24,609
Issuance of Common Stock for directors' fees (in shares)	1,371
Balances at Dec. 29, 2012	28,585,498	(19,105,723)	78,717,589	(16,615,265)	71,582,099
Balances (in shares) at Dec. 29, 2012	8,914,478	(2,694,729)
Net income			6,901,921		6,901,921
Cash dividends declared			(2,612,839)		(2,612,839)
Currency translation adjustment				(656,972)	(656,972)
Change in pension and postretirement benefit costs, net of tax				6,254,558	6,254,558
Issuance of Common Stock upon the exercise of stock options	13,580				13,580
Issuance of Common Stock upon the exercise of stock options (in shares)	1,000
Tax benefit from exercise of non-qualified stock options and disqualifying dispositions of incentive stock options					0
Issuance of Common Stock for directors' fees	22,504				22,504
Issuance of Common Stock for directors' fees (in shares)	1,419
Balances at Dec. 28, 2013	28,621,582	(19,105,723)	83,006,671	(11,017,679)	81,504,851
Balances (in shares) at Dec. 28, 2013	8,916,897	(2,694,729)
Net income			7,661,476		7,661,476
Cash dividends declared			(2,987,480)		(2,987,480)
Currency translation adjustment				(1,128,327)	(1,128,327)
Change in pension and postretirement benefit costs, net of tax				(10,386,089)	(10,386,089)
Issuance of Common Stock upon the exercise of stock options	271,600				271,600
Issuance of Common Stock upon the exercise of stock options (in shares)	20,000
Tax benefit from exercise of non-qualified stock options and disqualifying dispositions of incentive stock options	8,882				8,882
Issuance of Common Stock for directors' fees	29,994				29,994
Issuance of Common Stock for directors' fees (in shares)	1,845
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)