v3.25.2
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2025
Jul. 31, 2025
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2025  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Trading Symbol RPTX  
Entity Registrant Name Repare Therapeutics Inc.  
Entity Central Index Key 0001808158  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   42,959,172
Title of 12(b) Security Common shares, no par value  
Security Exchange Name NASDAQ  
Entity File Number 001-39335  
Entity Incorporation, State or Country Code A8  
Entity Tax Identification Number 00-0000000  
Entity Address, Address Line One 7171 Frederick-Banting  
Entity Address, Address Line Two Building 2  
Entity Address, Address Line Three Suite 270  
Entity Address, City or Town St-Laurent  
Entity Address, State or Province QC  
Entity Address, Country CA  
Entity Address, Postal Zip Code H4S 1Z9  
City Area Code 857  
Local Phone Number 412-7018  
Document Quarterly Report true  
Document Transition Report false