Note 2 - Discontinued Operations - Asset and Liabilities in Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 26, 2020	Dec. 28, 2019	Mar. 31, 2020	Sep. 28, 2019
Noncurrent Assets Held For Sale-Discontinued Operations	$ 822	$ 1,054	$ 822	$ 1,054	$ 1,026
Current Liabilities Held For Sale-Discontinued Operations	0	2,744	0	2,744	880
Net Earnings From Discontinued Operations, Net of Tax	0	(955)	0	(955)
Modesto Facility [Member] | Discontinued Operations, Disposed of by Sale [Member]
Other Current Assets	263		263		182	$ 98
Current Assets Held For Sale-Discontinued Operations	263		263		182	98
Other Assets	822		822		1,026	1,054
Noncurrent Assets Held For Sale-Discontinued Operations	822		822		1,026	1,054
Accounts Payable and Accrued Expenses	0		0		880	2,744
Current Liabilities Held For Sale-Discontinued Operations	0		0		$ 880	$ 2,744
Net Sales	0	0	0	0
Cost of Product Sold	0	57	0	57
Plant Restructuring Credit (a)	0	(902)	0	(902)
Earnings From Discontinuned Operations Before Income Taxes	0	(845)	0	(845)
Gain on the Sale of Assets Before Income Taxes	0	(430)	0	(430)
Income Tax Expense	0	320	0	320
Net Earnings From Discontinued Operations, Net of Tax	$ 0	$ (955)	$ 0	$ (955)