Quarterly Results of Operations (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Mar. 26, 2017	Dec. 25, 2016	Sep. 25, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 27, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 26, 2017	Mar. 27, 2016	Mar. 29, 2015
Summarized quarterly financial data
Revenues	$ 122,602,900	$ 147,198,400	$ 134,633,800	$ 128,860,000	$ 114,154,100	$ 139,510,700	$ 142,353,300	$ 134,664,000	$ 533,295,100	$ 530,682,100	$ 549,619,000
Cost of goods sold	96,665,300	117,229,800	105,878,200	101,754,000	91,135,200	110,057,300	111,841,600	105,682,100	421,527,300	418,716,200	431,980,500
Gross profit	25,937,600	29,968,600	28,755,600	27,106,000	23,018,900	29,453,400	30,511,700	28,981,900	111,767,800	111,965,900	117,638,500
Selling, general and administrative expenses	26,890,400	27,860,700	26,709,500	26,955,700	26,202,100	24,742,400	25,865,400	26,122,400	108,416,300	102,932,300	102,686,700
Restructuring charges	806,600								806,600		573,400
Operating expenses	27,697,000	27,860,700	26,709,500	26,955,700	26,202,100	24,742,400	25,865,400	26,122,400
Income from operations	(1,759,400)	2,107,900	2,046,100	150,300	(3,183,200)	4,711,000	4,646,300	2,859,500	2,544,900	9,033,600	14,378,400
Interest, net	(7,100)	37,100	17,200	11,400	12,400	55,500	47,100	46,300	58,600	161,300	167,300
Income before provision for income taxes	(1,752,300)	2,070,800	2,028,900	138,900	(3,195,600)	4,655,500	4,599,200	2,813,200	2,486,300	8,872,300	14,211,100
Provision for income taxes	(895,000)	843,100	1,034,700	58,400	(1,205,800)	1,768,800	1,850,900	1,117,900	1,041,200	3,531,800	5,576,800
Net income	$ (857,300)	$ 1,227,700	$ 994,200	$ 80,500	$ (1,989,800)	$ 2,886,700	$ 2,748,300	$ 1,695,300	$ 1,445,100	$ 5,340,500	$ 8,634,300
Diluted (loss) earnings per share (in dollars per share)	$ (0.10)	$ 0.15	$ 0.12	$ 0.01	$ (0.24)	$ 0.35	$ 0.33	$ 0.20	$ 0.17	$ 0.65	$ 1.04
Cash dividends declared per common share (in dollars per share)	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.80	$ 0.80	$ 0.80