Quarterly Results of Operations (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Mar. 28, 2021	Dec. 27, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 28, 2021	Mar. 29, 2020	Mar. 31, 2019
Summarized quarterly financial data
Revenues	$ 88,733,100	$ 99,237,600	$ 88,892,400	$ 96,477,600	$ 105,839,700	$ 100,844,000	$ 103,651,000	$ 98,679,700	$ 373,340,700	$ 409,014,400	$ 419,044,800
Cost of goods sold	71,907,100	81,921,900	71,771,200	80,024,900	86,251,300	81,196,300	83,466,700	78,458,200	305,625,100	329,372,500	334,640,100
Gross profit	16,826,000	17,315,700	17,121,200	16,452,700	19,588,400	19,647,700	20,184,300	20,221,500	67,715,600	79,641,900	84,404,700
Selling, general and administrative expenses	19,580,000	23,606,800	20,787,800	21,532,500	23,547,600	21,994,800	22,029,900	24,432,900	85,507,100	92,005,200	95,347,000
Goodwill impairment					9,108,600					9,108,600
Restructuring charges								488,000		488,000
Operating expenses	19,580,000	23,606,800	20,787,800	21,532,500	32,656,200	21,994,800	22,029,900	24,920,900
Operating loss	(2,754,000)	(6,291,100)	(3,666,600)	(5,079,800)	(13,067,800)	(2,347,100)	(1,845,600)	(4,699,400)	(17,791,500)	(21,959,900)	(10,942,300)
Interest, net	58,500	151,200	105,900	110,700	204,600	367,900	335,100	208,700	426,300	1,116,300	853,800
Loss from continuing operations before (benefit from) provision for income taxes	(2,812,500)	(6,442,300)	(3,772,500)	(5,190,500)	(13,272,400)	(2,715,000)	(2,180,700)	(4,908,100)	(18,217,800)	(23,076,200)	(11,796,100)
(Benefit from) provision for income taxes	(1,958,000)	(740,400)	(824,300)	(321,800)	(5,297,200)	(641,000)	(109,600)	(1,427,000)	(3,844,500)	(7,474,800)	(2,913,800)
Net loss from continuing operations	(854,500)	(5,701,900)	(2,948,200)	(4,868,700)	(7,975,200)	(2,074,000)	(2,071,100)	(3,481,100)	(14,373,300)	(15,601,400)	(8,882,300)
(Loss) income from discontinued operations, net of taxes	(2,075,700)	4,787,500	2,681,300	237,300	(6,101,500)	(2,947,400)	2,093,100	988,300	5,630,400	(5,967,500)	14,428,100
Net loss	$ (2,930,200)	$ (914,400)	$ (266,900)	$ (4,631,400)	$ (14,076,700)	$ (5,021,400)	$ 22,000	$ (2,492,800)	$ (8,742,900)	$ (21,568,900)	$ 5,545,800
Basic and diluted (loss) income per share
Continuing operations (in dollars per share)	$ (0.10)	$ (0.66)	$ (0.34)	$ (0.56)	$ (0.93)	$ (0.24)	$ (0.24)	$ (0.41)
Discontinued operations (in dollars per share)	(0.24)	0.55	0.31	0.03	(0.71)	(0.35)	0.24	0.12
Consolidated operations (in dollars per share)	$ (0.33)	$ (0.11)	$ (0.03)	$ (0.54)	$ (1.65)	$ (0.59)	$ 0.00	$ (0.29)
Basic weighted-average common shares outstanding (in shares)	8,814,859	8,699,937	8,656,877	8,617,803	8,554,348	8,541,020	8,650,320	8,494,168	8,697,369	8,526,965	8,436,796
Basic and diluted weighted-average common shares outstanding (in shares)	8,814,859	8,699,937	8,656,877	8,617,803	8,554,348	8,541,020	8,650,320	8,494,168	8,697,369	8,526,965	8,436,796
Cash dividends declared per common share (in dollars per share)					$ 0.02	$ 0.20	$ 0.20	$ 0.20		$ 0.62	$ 0.80