v3.26.1
Cover - shares
 3 Months Ended
Mar. 31, 2026
May 11, 2026
Cover [Abstract]    
Entity Registrant Name 374WATER INC.  
Entity Central Index Key 0000933972  
Document Type 10-Q  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Small Business true  
Entity Shell Company false  
Entity Emerging Growth Company false  
Entity Current Reporting Status Yes  
Document Period End Date Mar. 31, 2026  
Entity Filer Category Non-accelerated Filer  
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2026  
Entity Common Stock Shares Outstanding   17,495,504
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 000-27866  
Entity Incorporation State Country Code DE  
Entity Tax Identification Number 88-0271109  
Entity Address Address Line 1 100 Southcenter Court  
Entity Address Address Line 2 Suite 200  
Entity Address City Or Town Morrisville  
Entity Address State Or Province NC  
Entity Address Postal Zip Code 27560  
City Area Code 440  
Local Phone Number 601-9677  
Security 12b Title Common Stock, par value $0.0001  
Trading Symbol SCWO  
Security Exchange Name NASDAQ  
Entity Interactive Data Current Yes