Document And Entity Information - USD ($)	12 Months Ended
Sep. 24, 2016	Nov. 08, 2016	Mar. 24, 2016
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	--09-24
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding (in shares)		18,682,723
Entity Public Float			$ 1,568,251,219
Document Type	10-K
Document Period End Date	Sep. 24, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
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End date of current fiscal year in the format --MM-DD.

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This is focus fiscal year of the document report in CCYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006.

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The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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