v3.26.1
Cover - shares
 6 Months Ended
Jun. 30, 2026
Aug. 11, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Entity Interactive Data Current Yes  
Amendment Flag false  
Document Period End Date Jun. 30, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Entity Registrant Name INFLECTION POINT ACQUISITION CORP. III  
Entity Central Index Key 0002012318  
Entity File Number 001-42614  
Entity Tax Identification Number 00-0000000  
Entity Incorporation, State or Country Code E9  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Shell Company true  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Address, Address Line One 167 Madison Avenue  
Entity Address, Address Line Two Suite 205 #1017  
Entity Address, City or Town New York  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 10016  
City Area Code (212)  
Local Phone Number 295-5830  
Units, each consisting of one Class A ordinary share, $0.0001 par value, and one right to receive one-tenth (1/10) of one Class A ordinary share    
Document Information [Line Items]    
Title of 12(b) Security Units, each consisting of one Class A ordinary share, $0.0001 par value, and one right to receive one-tenth (1/10) of one Class A ordinary share  
Trading Symbol IPCXU  
Security Exchange Name NASDAQ  
Class A ordinary shares, par value $0.0001 par value    
Document Information [Line Items]    
Title of 12(b) Security Class A ordinary shares, par value $0.0001 par value  
Trading Symbol IPCX  
Security Exchange Name NASDAQ  
Rights, each entitling the holder to receive one tenth (1/10) of one Class A ordinary share    
Document Information [Line Items]    
Title of 12(b) Security Rights, each entitling the holder to receive one tenth (1/10) of one Class A ordinary share  
Trading Symbol IPCXR  
Security Exchange Name NASDAQ  
Class A Ordinary Shares    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   26,040,000
Class B Ordinary Shares    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   8,433,333