Note C - Income Per Share - Earnings Per Share Reconciliation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Mar. 26, 2017	[1]	Dec. 25, 2016	[1]	Sep. 25, 2016	[1]	Jun. 26, 2016	[1]	Mar. 27, 2016	[1]	Dec. 27, 2015	[1]	Sep. 27, 2015	[1]	Jun. 28, 2015	[1]	Mar. 26, 2017	Mar. 27, 2016	Mar. 29, 2015
Net income, basic calculation																	$ 7,485	$ 6,096	$ 11,703
Number of shares, basic calculation (in shares)	4,176,000		4,175,000		4,172,000		4,166,000		4,297,000		4,408,000		4,432,000		4,584,000		4,172,000	4,430,000	4,486,000
Net income per share, basic calculation (in dollars per share)	$ 0.17		$ 0.17		$ 0.60		$ 0.85		$ 0.12		$ 0.10		$ 0.64		$ 0.50		$ 1.79	$ 1.38	$ 2.61
Effect of dilutive employee stock options (in shares)																	34,000	33,000	102,000
Net income per share, effect of dilutive employee stock options (in dollars per share)																	$ (0.01)	$ (0.01)	$ (0.06)
Net income, diluted calculation																	$ 7,485	$ 6,096	$ 11,703
Number of shares, diluted calculation (in shares)	4,217,000		4,209,000		4,207,000		4,191,000		4,337,000		4,444,000		4,449,000		4,621,000		4,206,000	4,463,000	4,588,000
Net income, diluted calculation (in dollars per share)	$ 0.17		$ 0.17		$ 0.60		$ 0.85		$ 0.12		$ 0.10		$ 0.64		$ 0.50		$ 1.78	$ 1.37	$ 2.55

[1] 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.