Income Taxes - Calculation error of deferred tax liability (Details) - USD ($)	3 Months Ended								12 Months Ended
	Apr. 01, 2018	Dec. 24, 2017	Sep. 24, 2017	Jun. 25, 2017	Mar. 26, 2017	Dec. 25, 2016	Sep. 25, 2016	Jun. 26, 2016	Apr. 01, 2018	Mar. 26, 2017	Mar. 27, 2016
Error adjustment
Net deferred tax assets	$ 710,500								$ 710,500
Provision for income taxes	(76,800)	$ 501,900	$ 1,318,300	$ 533,800	$ (895,000)	$ 843,100	$ 1,034,700	$ 58,400	2,277,200	$ 1,041,200	$ 3,531,800
Net income	1,168,400	$ 1,570,200	$ 1,773,900	$ 682,900	$ (857,300)	$ 1,227,700	$ 994,200	$ 80,500	$ 5,195,400	$ 1,445,100	$ 5,340,500
Basic earnings per share (in dollars per share)									$ 0.62	$ 0.17	$ 0.65
Net cash (used in) provided by operating activities									$ (9,247,100)	$ 3,051,300	$ 20,141,100
Error in calculation of deferred tax liability relating to cash surrender value
Error adjustment
Net deferred tax assets	500,000								500,000
Provision for income taxes									(500,000)
Net income	$ 500,000
Basic earnings per share (in dollars per share)	$ 0.06
Net cash (used in) provided by operating activities									$ 0