Consolidated Statements of Changes in Shareholders' Equity - USD ($)	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Total
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
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 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
Increase (Decrease) in Stockholders' Equity
Net 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
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 (in dollars)	$ 500	680,600			681,100
Exercise of stock options (in shares)	48,125
Cash dividends paid				(1,704,200)	(1,704,200)
Net 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 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
Balance at Mar. 29, 2020	$ 101,400	65,318,500	(58,496,200)	76,779,000	$ 83,702,700
Balance (in shares) at Mar. 29, 2020	8,577,549				8,577,549
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 200	132,500			$ 132,700
Proceeds from issuance of stock (in shares)	23,676
Treasury stock purchases			(58,800)		(58,800)
Treasury stock purchases (in shares)	(12,781)
Non-cash stock compensation expense	$ 600	311,300			311,900
Non-cash stock compensation expense (in shares)	48,685
Net loss				(4,631,400)	(4,631,400)
Balance at Jun. 28, 2020	$ 102,200	65,762,300	(58,555,000)	72,147,600	79,457,100
Balance (in shares) at Jun. 28, 2020	8,637,129
Balance at Mar. 29, 2020	$ 101,400	65,318,500	(58,496,200)	76,779,000	$ 83,702,700
Balance (in shares) at Mar. 29, 2020	8,577,549				8,577,549
Increase (Decrease) in Stockholders' Equity
Net loss					$ (5,812,700)
Balance at Dec. 27, 2020	$ 103,300	66,765,600	(62,800)	12,411,300	$ 79,217,400
Balance (in shares) at Dec. 27, 2020	8,740,670				8,740,670
Balance at Jun. 28, 2020	$ 102,200	65,762,300	(58,555,000)	72,147,600	$ 79,457,100
Balance (in shares) at Jun. 28, 2020	8,637,129
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 400	224,500			224,900
Proceeds from issuance of stock (in shares)	47,792
Treasury stock purchases			(14,100)		(14,100)
Treasury stock purchases (in shares)	(2,250)
Non-cash stock compensation expense	$ 100	316,600			316,700
Non-cash stock compensation expense (in shares)	7,500
Retirement of treasury stock (in dollars)			58,555,000	(58,555,000)
Net loss				(266,900)	(266,900)
Balance at Sep. 27, 2020	$ 102,700	66,303,400	(14,100)	13,325,700	79,717,700
Balance (in shares) at Sep. 27, 2020	8,690,171
Increase (Decrease) in Stockholders' Equity
Proceeds from issuance of stock	$ 200	131,600			131,800
Proceeds from issuance of stock (in shares)	23,081
Treasury stock purchases			(48,700)		(48,700)
Treasury stock purchases (in shares)	(8,000)
Non-cash stock compensation expense	$ 400	330,600			331,000
Non-cash stock compensation expense (in shares)	35,418
Net loss				(914,400)	(914,400)
Balance at Dec. 27, 2020	$ 103,300	$ 66,765,600	$ (62,800)	$ 12,411,300	$ 79,217,400
Balance (in shares) at Dec. 27, 2020	8,740,670				8,740,670