v3.19.2
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 01, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Document Period End Date Jun. 30, 2019  
Entity Registrant Name Albireo Pharma, Inc.  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   12,685,326
Entity Central Index Key 0001322505  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Amendment Flag false