v3.26.1
Cover Page - shares
 3 Months Ended
Mar. 31, 2026
May 05, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 001-42271  
Entity Registrant Name BICARA THERAPEUTICS INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 83-2903745  
Entity Address, Address Line One 116 Huntington Ave  
Entity Address, Address Line Two Suite 703  
Entity Address, City or Town Boston  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02116  
City Area Code 617  
Local Phone Number 468-4219  
Title of 12(b) Security Common Stock, par value $0.0001  
Trading Symbol BCAX  
Security Exchange Name NASDAQ  
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   65,703,866
Entity Central Index Key 0002023658  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Amendment Flag false