v3.26.1
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2026
Aug. 06, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 30, 2026  
Entity File Number 001-39712  
Entity Registrant Name OLEMA PHARMACEUTICALS, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 30-0409740  
Entity Address, Address Line One 780 Brannan Street  
Entity Address, City or Town San Francisco  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94103  
City Area Code 415  
Local Phone Number 651‑3316  
Title of 12(b) Security Common Stock  
Trading Symbol OLMA  
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 false  
Entity Shell Company false  
Entity Central Index Key 0001750284  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   87,497,607
Class of Warrant or Right, Outstanding 13,594,149 13,594,149