v3.26.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2026
May 20, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Mar. 31, 2026  
Document Fiscal Year Focus 2026  
Current Fiscal Year End Date --12-31  
Entity File Number 001-43233  
Entity Central Index Key 0002096997  
Document Fiscal Period Focus Q1  
Entity Registrant Name Kailera Therapeutics, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 99-3088927  
Amendment Flag false  
Entity Address, Address Line One 180 Third Avenue  
Entity Address, Address Line Two 4th Floor  
Entity Address, City or Town Waltham  
Entity Address, State or Province MA  
City Area Code 781  
Entity Address, Postal Zip Code 02451  
Local Phone Number 317-0290  
Title of 12(b) Security Common Stock, par value $0.00001 per share  
Trading Symbol KLRA  
Security Exchange Name NASDAQ  
Entity Current Reporting Status No  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   129,565,608