Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 30, 2020
Document And Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	001-33451
Entity Registrant Name	Albireo Pharma, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	90-0136863
Entity Address, Address Line One	10 Post Office Square
Entity Address, Address Line Two	Suite 1000
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02109
City Area Code	857
Local Phone Number	254-5555
Title of 12(b) Security	Common Stock
Trading Symbol	ALBO
Security Exchange Name	NASDAQ
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		14,990,711
Entity Central Index Key	0001322505
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Trading Symbol	ALBO