Note 1 - Basis of Preparation and Presentation (Details Textual) $ in Millions	3 Months Ended	6 Months Ended
Sep. 26, 2026 USD ($)	Sep. 26, 2026 USD ($)
Number of States in which Entity Operates	9	9
TSA Fees	$ 0.2	$ 1.6
Green Giant [Member]
Business Combination, Consideration Transferred, Contingent Consideration, Assets Receivable		$ 1.7
Seneca Food Plants [Member]
Number of Real Estate Properties	27	27

Represents the amount of assets receivable related to a contingent consideration transferred under a business combination.

No definition available.

+ Details

Name:	senea_BusinessCombinationConsiderationTransferredContingentConsiderationAssetsReceivable
Namespace Prefix:	senea_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of TSA fees during the period.

+ References

No definition available.

+ Details

Name:	senea_TSAFees
Namespace Prefix:	senea_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-2

+ Details

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

+ Details

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_BusinessAcquisitionAxis=senea_GreenGiantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=senea_SenecaFoodPlantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: