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Document and Entity Information (USD $)
12 Months Ended
Mar. 31, 2015
Oct. 01, 2014
Jun. 05, 2015
Document And Entity Information [Abstract]      
Document Type 10-K    
Document period end date Mar. 31, 2015    
Amendment flag false    
Document Period Focus Q4    
Document Fiscal Year Focus 2015    
Current fiscal year end date --03-31    
Entity central index key 0000088948    
Entity current reporting status Yes    
Entity filer category Accelerated Filer    
Entity registrant name SENECA FOODS CORP /NY/    
Entity voluntary filers No    
Entity well known seasoned issuer No    
Class Of Stock [Line Items]      
Trading Symbol SENEA    
Entity public float   $ 236,271,000dei_EntityPublicFloat  
Common Class A Member      
Class Of Stock [Line Items]      
Entity common stock shares outstanding     7,926,280dei_EntityCommonStockSharesOutstanding
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Common Class B Member      
Class Of Stock [Line Items]      
Entity common stock shares outstanding     1,967,958dei_EntityCommonStockSharesOutstanding
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= us-gaap_CommonClassBMember