v3.26.1
Cover - shares
 6 Months Ended
Jun. 30, 2026
Aug. 07, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 001-40631  
Entity Registrant Name Caribou Biosciences, Inc.  
Entity Incorporation State Country Code DE  
Entity Tax Identification Number 45-3728228  
Entity Address Address Line1 2929 7th Street  
Entity Address, Address Line Two Suite 105  
Entity Address City Or Town Berkeley  
Entity Address, State and Province CA  
Entity Address Postal Zip Code 94710  
City Area Code 510  
Local Phone Number 982-6030  
Security12b Title Common Stock, par value $0.0001 per share  
Trading Symbol CRBU  
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   107,207,513
Entity Central Index Key 0001619856  
Current Fiscal Year End Date --12-31  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Document Fiscal Year Focus 2026