XML 12 R1.htm IDEA: XBRL DOCUMENT v3.6.0.2
Document And Entity Information - shares
 3 Months Ended
Dec. 24, 2016
Jan. 19, 2017
Document Information [Line Items]    
Entity Registrant Name J&J SNACK FOODS CORP  
Entity Central Index Key 0000785956  
Trading Symbol jjsf  
Current Fiscal Year End Date --09-30  
Entity Filer Category Large Accelerated Filer  
Entity Current Reporting Status No  
Entity Voluntary Filers No  
Entity Well-known Seasoned Issuer Yes  
Entity Common Stock, Shares Outstanding (in shares)   18,709,265
Document Type 10-Q  
Document Period End Date Dec. 24, 2016  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q1  
Amendment Flag false