Note 11 - Pension Plans - Contributions for All Multi-employer Pension Plans (Details) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2022	May 01, 2021	May 02, 2020
Fund	$ (2,460)	$ (2,381)	$ (2,408)
Fund	2,460	2,381	2,408
CSSS Fund [Member]
Fund	(1,462)	(1,469)	(1,424)
Fund	1,462	1,469	1,424
WCT Fund [Member]
Fund	(817)	(746)	(799)
Fund	817	746	799
Other Multi-employer Pension Funds [Member]
Fund	(181)	(166)	(185)
Fund	$ 181	$ 166	$ 185

Amount of cost for employer contribution to multiemployer plan. Multiemployer plan includes, but is not limited to, pension plan determined to be individually significant and insignificant and other postretirement benefit plan.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 55
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=35742348&loc=SL14450788-114948

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 35
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=29639808&loc=d3e29008-114946

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 11
-URI https://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947

Name:	us-gaap_MultiemployerPlanEmployerContributionCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration