XML 11 R1.htm IDEA: XBRL DOCUMENT v3.21.1
Document and Entity Information - shares
 3 Months Ended
Mar. 28, 2021
Apr. 25, 2021
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 28, 2021  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q1  
Title of 12(b) Security Common Stock, $0.01 par value  
Trading Symbol PBPB  
Security Exchange Name NASDAQ  
Entity Registrant Name Potbelly Corporation  
Entity Central Index Key 0001195734  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Current Fiscal Year End Date --12-26  
Entity Filer Category Non-accelerated Filer  
Entity Shell Company false  
Entity Bankruptcy Proceedings, Reporting Current true  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   27,966,488
Entity File Number 001-36104  
Entity Tax Identification Number 36-4466837  
Entity Address, Address Line One 111 N. Canal Street  
Entity Address, Address Line Two Suite 325  
Entity Address, City or Town Chicago  
Entity Address, State or Province IL  
Entity Incorporation, State or Country Code DE  
Entity Address, Postal Zip Code 60606  
City Area Code 312  
Local Phone Number 951-0600  
Document Quarterly Report true  
Document Transition Report false