v3.26.1
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2026
Aug. 10, 2026
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Entity Registrant Name OBSIDIAN THERAPEUTICS, INC.  
Entity Central Index Key 0002130606  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Shell Company false  
Entity Small Business false  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Current Reporting Status No  
Entity File Number 001-43430  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 42-1977778  
Entity Address, Address Line One 1030 Massachusetts Avenue  
Entity Address, City or Town Cambridge  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02138  
City Area Code (781)  
Local Phone Number 806-6245  
Title of 12(b) Security Common stock, par value $0.0001 per share  
Trading Symbol OBX  
Security Exchange Name NASDAQ  
Document Quarterly Report true  
Document Transition Report false  
Entity Interactive Data Current Yes  
Entity Common Stock, Shares Outstanding   61,772,876
Former Address    
Document Information [Line Items]    
Entity Information, Former Legal or Registered Name Gazelle Parent, Inc.  
Entity Address, Address Line One 1030 Massachusetts Avenue  
Entity Address, City or Town Cambridge  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02138  
City Area Code (781)  
Local Phone Number 806-6245