Note 10 - Plant Restructuring - Restructuring Reserve (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Dec. 26, 2020	Sep. 26, 2020	Jun. 27, 2020	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Dec. 26, 2020	Dec. 28, 2019
Balance			$ 202			$ 226	$ 202	$ 226
Charge to expense	$ (118)	$ 24	263	$ 793	$ 1,146	4,806
Cash payments/write offs							(371)	(6,891)
Balance	0			80			0	80
Employee Severance [Member]
Balance			202			225	202	225
Charge to expense	0	8	219	28	386	586
Cash payments/write offs							(429)	(1,145)
Balance	0			80			0	80
Other Restructuring [Member]
Balance			0			1	0	1
Charge to expense	(118)	$ 16	$ 44	765	$ 760	$ 4,220
Cash payments/write offs							58	(5,746)
Balance	$ 0			$ 0			$ 0	$ 0