Consolidated Statements of Changes in Shareholders' Equity - USD ($)	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Total
Balance at Apr. 01, 2018	$ 99,000	$ 60,611,900	$ (57,503,000)	$ 104,843,700	$ 108,051,600
Balance (in shares) at Apr. 01, 2018	8,396,537
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 100	130,000			130,100
Proceeds from issuance of stock (in shares)	5,620
Treasury stock purchases			(111,100)		(111,100)
Treasury stock purchases (in shares)	(6,332)
Non-cash stock compensation expense	$ 200	320,300			320,500
Non-cash stock compensation expense (in shares)	26,257
Cash dividends paid				(1,684,200)	(1,684,200)
Net income (loss)				1,158,400	1,158,400
Balance at Jul. 01, 2018	$ 99,300	61,062,200	(57,614,100)	104,317,900	107,865,300
Balance (in shares) at Jul. 01, 2018	8,422,082
Balance at Apr. 01, 2018	$ 99,000	60,611,900	(57,503,000)	104,843,700	108,051,600
Balance (in shares) at Apr. 01, 2018	8,396,537
Increase (Decrease) in Stockholders' Equity
Net income (loss)					5,053,800
Balance at Dec. 30, 2018	$ 99,600	62,140,700	(57,614,100)	104,835,700	109,461,900
Balance (in shares) at Dec. 30, 2018	8,448,526
Balance at Jul. 01, 2018	$ 99,300	61,062,200	(57,614,100)	104,317,900	107,865,300
Balance (in shares) at Jul. 01, 2018	8,422,082
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 200	282,400			282,600
Proceeds from issuance of stock (in shares)	17,446
Non-cash stock compensation expense		384,800			384,800
Cash dividends paid				(1,687,000)	(1,687,000)
Net income (loss)				1,190,800	1,190,800
Balance at Sep. 30, 2018	$ 99,500	61,729,400	(57,614,100)	103,821,700	108,036,500
Balance (in shares) at Sep. 30, 2018	8,439,528
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 100	137,200			137,300
Proceeds from issuance of stock (in shares)	8,998
Non-cash stock compensation expense		274,100			274,100
Cash dividends paid				(1,690,600)	(1,690,600)
Net income (loss)				2,704,600	2,704,600
Balance at Dec. 30, 2018	$ 99,600	62,140,700	(57,614,100)	104,835,700	109,461,900
Balance (in shares) at Dec. 30, 2018	8,448,526
Balance at Mar. 31, 2019	$ 99,800	62,666,400	(57,614,100)	103,635,100	$ 108,787,200
Balance (in shares) at Mar. 31, 2019	8,468,529				8,468,529
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 100	143,100			$ 143,200
Proceeds from issuance of stock (in shares)	9,250
Treasury stock purchases			(189,100)		(189,100)
Treasury stock purchases (in shares)	(10,488)
Non-cash stock compensation expense	$ 400	338,500			338,900
Non-cash stock compensation expense (in shares)	41,256
Cash dividends paid				(1,702,600)	(1,702,600)
Net income (loss)				(2,492,800)	(2,492,800)
Balance at Jun. 30, 2019	$ 100,300	63,148,000	(57,803,200)	99,439,700	104,884,800
Balance (in shares) at Jun. 30, 2019	8,508,547
Balance at Mar. 31, 2019	$ 99,800	62,666,400	(57,614,100)	103,635,100	$ 108,787,200
Balance (in shares) at Mar. 31, 2019	8,468,529				8,468,529
Increase (Decrease) in Stockholders' Equity
Exercise of stock options (in shares)					48,125
Net income (loss)					$ (7,492,200)
Balance at Dec. 29, 2019	$ 101,100	64,854,700	(58,496,200)	91,026,600	$ 97,486,200
Balance (in shares) at Dec. 29, 2019	8,543,175				8,543,200
Balance at Jun. 30, 2019	$ 100,300	63,148,000	(57,803,200)	99,439,700	$ 104,884,800
Balance (in shares) at Jun. 30, 2019	8,508,547
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 200	283,600			283,800
Proceeds from issuance of stock (in shares)	19,236
Treasury stock purchases			(681,100)		(681,100)
Treasury stock purchases (in shares)	(44,009)
Non-cash stock compensation expense		391,800			391,800
Exercise of stock options	$ 500	680,600			681,100
Exercise of stock options (in shares)	48,125
Cash dividends paid				(1,704,200)	(1,704,200)
Net income (loss)				22,000	22,000
Balance at Sep. 29, 2019	$ 101,000	64,504,000	(58,484,300)	97,757,500	103,878,200
Balance (in shares) at Sep. 29, 2019	8,531,899
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 100	138,000			138,100
Proceeds from issuance of stock (in shares)	9,570
Treasury stock purchases			(11,900)		(11,900)
Treasury stock purchases (in shares)	(824)
Non-cash stock compensation expense		212,700			212,700
Non-cash stock compensation expense (in shares)	2,530
Cash dividends paid				(1,709,500)	(1,709,500)
Net income (loss)				(5,021,400)	(5,021,400)
Balance at Dec. 29, 2019	$ 101,100	$ 64,854,700	$ (58,496,200)	$ 91,026,600	$ 97,486,200
Balance (in shares) at Dec. 29, 2019	8,543,175				8,543,200