v3.25.2
Cover Page - shares
 6 Months Ended
Jun. 30, 2025
Jul. 30, 2025
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-40720  
Entity Registrant Name OMNIAB, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 98-1584818  
Entity Address, Address Line One 5980 Horton Street, Suite 600  
Entity Address, City or Town Emeryville  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94608  
City Area Code (510)  
Local Phone Number 250-7800  
Entity Current Reporting Status Yes  
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   122,701,294
Current Fiscal Year End Date --12-31  
Amendment Flag false  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001846253  
Common Stock    
Document Information [Line Items]    
Title of 12(b) Security Common stock, $0.0001 par value per share  
Trading Symbol OABI  
Security Exchange Name NASDAQ  
Forward purchase warrants    
Document Information [Line Items]    
Title of 12(b) Security Warrants to purchase common stock  
Trading Symbol OABIW  
Security Exchange Name NASDAQ