v3.10.0.1
Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 29, 2018
Feb. 22, 2019
Jun. 30, 2018
Document Documentand Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 29, 2018    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2018    
Entity Registrant Name DUNKIN' BRANDS GROUP, INC.    
Entity Central Index Key 0001357204    
Current Fiscal Year End Date --12-29    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   82,636,134  
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Public Float     $ 5,740
Entity Well-known Seasoned Issuer Yes    
Trading Symbol DNKN