Document and Entity Information - shares
9 Months Ended
Sep. 28, 2019
Nov. 01, 2019
Cover page.    
Title of 12(b) Security Common Stock, $0.001 par value per share  
Entity Current Reporting Status Yes  
Entity Incorporation, State or Country Code DE  
Document Transition Report false  
Document Quarterly Report true  
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 28, 2019  
Entity File Number 001-35258  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Trading Symbol DNKN  
Entity Registrant Name DUNKIN’ BRANDS GROUP, INC.  
Entity Address, Address Line One 130 Royall Street  
Entity Address, City or Town Canton  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02021  
City Area Code 781  
Local Phone Number 737-3000  
Entity Shell Company false  
Entity Central Index Key 0001357204  
Current Fiscal Year End Date --12-28  
Entity Filer Category Large Accelerated Filer  
Entity Emerging Growth Company false  
Entity Small Business false  
Entity Common Stock, Shares Outstanding   82,843,010
Entity Tax Identification Number 20-4145825  
Security Exchange Name NASDAQ  
Entity Interactive Data Current Yes