Note C - Income Per Share - Earnings Per Share Reconciliation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Mar. 31, 2019	[1],[2]	Dec. 23, 2018	[2]	Sep. 23, 2018	[2]	Jun. 24, 2018	[2]	Mar. 25, 2018	[2]	Dec. 24, 2017	[2]	Sep. 24, 2017	[2]	Jun. 25, 2017	[2]	Mar. 31, 2019	Mar. 25, 2018	Mar. 26, 2017
Net income, basic calculation																	$ 21,493	$ 2,630	$ 7,485
Number of shares, basic calculation (in shares)	4,187,000		4,187,000		4,188,000		4,185,000		4,185,000		4,185,000		4,179,000		4,177,000		4,187,000	4,181,000	4,172,000
Net income per share, basic calculation (in dollars per share)	$ 0.60		$ 2.32		$ 1.07		$ 1.15		$ 0.09		$ (0.90)		$ 0.75		$ 0.70		$ 5.13	$ 0.63	$ 1.79
Effect of dilutive employee stock options (in shares)																	33,000	40,000	34,000
Effect of dilutive employee stock option (in dollars per share)																	$ (0.04)	$ (0.01)	$ (0.01)
Net income, diluted calculation																	$ 21,493	$ 2,630	$ 7,485
Number of shares, diluted calculation (in shares)	4,202,000		4,221,000		4,231,000		4,226,000		4,228,000		4,185,000		4,212,000		4,215,000		4,220,000	4,221,000	4,206,000
Net income per share, diluted calculation (in dollars per share)	$ 0.59		$ 2.30		$ 1.06		$ 1.13		$ 0.09		$ (0.90)		$ 0.74		$ 0.69		$ 5.09	$ 0.62	$ 1.78

[1] The fourth quarter fiscal 2019 was comprised of 14 weeks, as compared to all other quarters which were comprised of 13 weeks.

[2] The sum of the quarters may not equal the full year per share amounts included in the accompanying consolidated statements of earnings due to the effect of the weighted average number of shares outstanding during the fiscal years as compared to the quarters.