Note M - Share-based Compensation - Outstanding Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 29, 2019	Mar. 31, 2019
Options outstanding (in shares)		42,234
Options outstanding, weighted average exercise price (in dollars per share)		$ 46.807
Options outstanding, weighted average remaining contractual life (Year)	1 year 116 days	3 years 255 days
Options outstanding, aggregate intrinsic value	$ 1,127
Options granted (in shares)		0	10,000
Granted, weighted average exercise price (in dollars per share)			$ 89.90
Options exercised (in shares)		(32,234)
Exercised, weighted average exercise price (in dollars per share)		$ 33.438
Exercised, aggregate intrinsic value		$ 1,134
Options outstanding (in shares)		10,000	42,234
Options outstanding, weighted average exercise price (in dollars per share)		$ 89.90	$ 46.807
Options exercisable (in shares)		3,333
Options exercisable, weighted average exercise price (in dollars per share)		$ 89.90
Options exercisable, weighted average remaining contractual life (Year)		3 years 255 days