Note 10 - Other Operating Income and Expense (Details Textual) - Other Operating Income (Expense) [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 01, 2022	Dec. 26, 2020	Jan. 01, 2022	Dec. 26, 2020
Pension and Other Postretirement Benefits Cost (Reversal of Cost), Total	$ 0.5		$ 2.4	$ 1.2
Miscellaneous Income (Expense)	$ 0.1		(0.3)
Unused Fixed Assets [Member]
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property		$ (0.3)
Gain (Loss) on Extinguishment of Debt, Total			0.5
Properties Held For Sale [Member]
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property			0.5
Air Transportation Equipment [Member]
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property			1.2
Midwest Plant [Member]
Gain (Loss) On Sale of Plant			$ 0.8
Equipment from Sold Northwest Plant [Member]
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property				(0.4)
Unused Fixed Assets from Northwest Plant [Member]
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property				(0.4)
Prepared Foods [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax, Total		$ 35.7		$ 35.7