Note 3 - Earnings Per Common Share - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 28, 2024	Sep. 30, 2023	Sep. 28, 2024	Sep. 30, 2023
Net earnings	$ 13,303	$ 24,779	$ 25,964	$ 47,890
Deduct preferred stock dividends paid	0	6	12	12
Undistributed net earnings	13,303	24,773	25,952	47,878
Earnings attributable to participating preferred shareholders	16	28	31	53
Earnings attributable to common shareholders	$ 13,287	$ 24,745	$ 25,921	$ 47,825
Weighted average common shares outstanding (in shares)	6,915	7,445	6,938	7,521
Basic earnings per common share (in dollars per share)	$ 1.92	$ 3.32	$ 3.74	$ 6.36
Earnings attributable to common shareholders	$ 13,287	$ 24,745	$ 25,921	$ 47,825
Add dividends on convertible preferred stock	5	5	10	10
Earnings attributable to common stock on a diluted basis	$ 13,292	$ 24,750	$ 25,931	$ 47,835
Additional shares to be issued under full conversion of preferred stock (in shares)	67	67	67	67
Total shares for diluted (in shares)	6,982	7,512	7,005	7,588
Diluted earnings per common share (in dollars per share)	$ 1.9	$ 3.29	$ 3.7	$ 6.3