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. 02, 2010	$ 26,236,477	$ (18,375,416)	$ 67,558,201	$ (8,821,958)	$ 66,597,304
Balances (in shares) at Jan. 02, 2010	8,709,384	(2,644,215)
Net income			5,543,005		5,543,005
Cash dividends declared			(3,181,587)		(3,181,587)
Currency translation adjustment				752,662	752,662
Change in pension and postretirement benefit costs, net of tax				(418,175)	(418,175)
Purchase of Common Stock for treasury		(730,307)			(730,307)
Purchase of Common Stock for treasury (in shares)		(50,514)
Issuance of Common Stock upon the exercise of stock options	1,348,585				1,348,585
Issuance of Common Stock upon the exercise of stock options (in shares)	141,750
Tax benefit from exercise of non-qualified stock options and disqualifying dispositions of incentive stock options	107,662				107,662
Issuance of Common Stock for directors' fees	24,594				24,594
Issuance of Common Stock for directors' fees (in shares)	1,628
Balances at Jan. 01, 2011	27,717,318	(19,105,723)	69,919,619	(8,487,471)	70,043,743
Balances (in shares) at Jan. 01, 2011	8,852,762	(2,694,729)
Net income			5,504,930		5,504,930
Cash dividends declared			(2,224,187)		(2,224,187)
Currency translation adjustment				(341,488)	(341,488)
Change in pension and postretirement benefit costs, net of tax				(4,607,131)	(4,607,131)
Issuance of Common Stock upon the exercise of stock options	651,390				651,390
Issuance of Common Stock upon the exercise of stock options (in shares)	54,500
Tax benefit from exercise of non-qualified stock options and disqualifying dispositions of incentive stock options	106,471				106,471
Issuance of Common Stock for directors' fees	24,600				24,600
Issuance of Common Stock for directors' fees (in shares)	1,345
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)
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
Miscellaneous			4		4
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)