XML 12 R1.htm IDEA: XBRL DOCUMENT v3.10.0.1
Document and Entity Information - shares
9 Months Ended
Sep. 29, 2018
Oct. 12, 2018
Document and Entity Information    
Entity Registrant Name WINMARK CORP  
Entity Central Index Key 0000908315  
Document Type 10-Q  
Document Period End Date Sep. 29, 2018  
Amendment Flag false  
Current Fiscal Year End Date --12-29  
Entity Current Reporting Status Yes  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   3,901,202
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3