Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 04, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Entity Registrant Name	Caribou Biosciences, Inc.
Entity Central Index Key	0001619856
Entity File Number	001-40631
Entity Tax Identification Number	45-3728228
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
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 Incorporation State Country Code	DE
Entity Address Postal Zip Code	94710
Local Phone Number	982-6030
City Area Code	510
Security12b Title	Common Stock, par value $0.0001 per share
Trading Symbol	CRBU
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		60,705,391