v3.26.1
Document And Entity Information - USD ($)
 12 Months Ended
Mar. 31, 2026
Sep. 26, 2025
Document Information [Line Items]    
Document Type 10-K  
Document Annual Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 0-01989  
Entity Registrant Name Seneca Foods Corporation  
Entity Incorporation, State or Country Code NY  
Entity Tax Identification Number 16-0733425  
Entity Address, Address Line One 350 WillowBrook Office Park  
Entity Address, City or Town Fairport  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 14450  
City Area Code 585  
Local Phone Number 495-4100  
Entity Well-known Seasoned Issuer No  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
ICFR Auditor Attestation Flag true  
Document Financial Statement Error Correction [Flag] false  
Entity Shell Company false  
Entity Public Float   $ 554,816,144
Auditor Name Deloitte & Touche LLP  
Auditor Location Rochester, NY  
Auditor Firm ID 34  
Entity Central Index Key 0000088948  
Current Fiscal Year End Date --03-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus FY  
Amendment Flag false  
Common Class A [Member]    
Document Information [Line Items]    
Title of 12(b) Security Common Stock Class A, $0.25 Par  
Trading Symbol SENEA  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding (in shares) 5,221,238  
Common Class B [Member]    
Document Information [Line Items]    
Title of 12(b) Security Common Stock Class B, $0.25 Par  
Trading Symbol SENEB  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding (in shares) 1,549,202