Consolidated Balance Sheets (Parenthetical) - USD ($)	Sep. 30, 2018	Apr. 01, 2018
Current assets:
Trade accounts receivable, allowance for doubtful accounts	$ 1,912,800	$ 1,094,900
Shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	500,000	500,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars shares)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	15,000,000	15,000,000
Common stock, issued (in shares)	14,161,026	14,111,703
Common stock, outstanding (in shares)	8,439,528	8,396,537
Treasury stock (in shares)	5,721,498	5,715,166