v3.25.3
Document and Entity Information - shares
 9 Months Ended
Sep. 30, 2025
Oct. 31, 2025
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2025  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Trading Symbol KURA  
Entity Registrant Name KURA ONCOLOGY, INC.  
Entity Central Index Key 0001422143  
Entity Current Reporting Status Yes  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Shell Company false  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   87,017,518
Entity File Number 001-37620  
Entity Tax Identification Number 61-1547851  
Entity Address, Address Line One 4930 Directors Place  
Entity Address, Address Line Two Suite 500  
Entity Address, City or Town San Diego  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 92121  
City Area Code 858  
Local Phone Number 500-8800  
Entity Interactive Data Current Yes  
Title of 12(b) Security Common Stock, par value $0.0001 per share  
Security Exchange Name NASDAQ  
Entity Incorporation, State or Country Code DE  
Document Quarterly Report true  
Document Transition Report false  
Former Address    
Document Information [Line Items]    
Entity Address, Address Line One 12730 High Bluff Drive  
Entity Address, Address Line Two Suite 400  
Entity Address, City or Town San Diego  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 92130