Note 4 - Revenue Recognition - Segment Revenue Disaggregated by Product Category Groups (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 26, 2020	Dec. 28, 2019
Net sales	$ 484,392	$ 392,971	$ 1,162,851	$ 1,027,898
Canned Vegetables [Member]
Net sales	394,500	297,300	917,800	757,400
Frozen [Member]
Net sales	27,300	30,600	76,300	89,700
Fruit [Member]
Net sales	30,700	32,200	73,400	81,800
Chip Products [Member]
Net sales	2,800	2,900	8,200	8,900
Prepared Foods [Member]
Net sales	23,500	25,500	71,900	78,900
Manufactured Product, Other [Member]
Net sales	$ 5,600	$ 4,500	$ 15,300	$ 11,200