v3.3.1.900
Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Mar. 09, 2016
Jun. 30, 2015
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Trading Symbol DRNA    
Entity Registrant Name DICERNA PHARMACEUTICALS INC    
Entity Central Index Key 0001399529    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Non-accelerated Filer    
Entity Common Stock, Shares Outstanding   20,647,983  
Entity Public Float     $ 70.2