Document And Entity Information - shares	3 Months Ended
	Dec. 29, 2018	Jan. 24, 2019
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	--09-28
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding (in shares)		18,782,640
Document Type	10-Q
Document Period End Date	Dec. 29, 2018
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false