v2.4.0.8
Document and Entity Information
9 Months Ended
Sep. 30, 2015
Nov. 02, 2015
Document and Entity Information [Abstract]    
Entity Registrant Name Blueprint Medicines Corp  
Entity Central Index Key 0001597264  
Document Type 10-Q  
Document Period End Date Sep. 30, 2015  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   27,100,791
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q3