Note 10 - Plant Restructuring - Restructuring Reserve (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Sep. 26, 2020	Jun. 27, 2020	Sep. 28, 2019	Jun. 29, 2019	Sep. 26, 2020	Sep. 28, 2019
Balance		$ 202		$ 226	$ 202	$ 226
Charge to expense	$ 24	263	$ 1,146	4,806
Cash payments/write offs					(459)	(5,817)
Balance	30		361		30	361
Employee Severance [Member]
Balance		202		225	202	225
Charge to expense	8	219	386	586
Cash payments/write offs					(399)	(836)
Balance	30		361		30	361
Other Restructuring [Member]
Balance		0		1	0	1
Charge to expense	16	$ 44	760	$ 4,220
Cash payments/write offs					(60)	(4,981)
Balance	$ 0		$ 0		$ 0	$ 0

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

Name:	us-gaap_RestructuringReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant