Document and Entity Information - shares	9 Months Ended
	Oct. 07, 2018	Nov. 12, 2018
Document and Entity Information
Entity Registrant Name	Smart & Final Stores, Inc.
Entity Central Index Key	0001563407
Document Type	10-Q
Document Period End Date	Oct. 07, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-30
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		76,007,689
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3