v3.10.0.1
Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Mar. 01, 2019
Jun. 30, 2018
Document And Entity Information [Abstract]      
Entity Registrant Name Albireo Pharma, Inc.    
Entity Central Index Key 0001322505    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Document Type 10-K    
Document Period End Date Dec. 31, 2018    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Trading Symbol albo    
Entity Filer Category Accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 421.1
Entity Common Stock, Shares Outstanding   12,026,025