v3.26.1
Cover - USD ($)
 12 Months Ended
Dec. 31, 2025
Mar. 27, 2026
Jun. 30, 2025
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Document Financial Statement Error Correction [Flag] false    
Entity Interactive Data Current Yes    
ICFR Auditor Attestation Flag false    
Amendment Flag false    
Document Period End Date Dec. 31, 2025    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Entity Information [Line Items]      
Entity Registrant Name General Purpose Acquisition Corp.    
Entity Central Index Key 0002085408    
Entity File Number 001-42986    
Entity Tax Identification Number 00-0000000    
Entity Incorporation, State or Country Code E9    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
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 Public Float     $ 0
Entity Contact Personnel [Line Items]      
Entity Address, Address Line One 59 Front Street    
Entity Address, City or Town Millbrook    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 12545    
Entity Phone Fax Numbers [Line Items]      
City Area Code 845    
Local Phone Number 677-4650    
Units [Member]      
Entity Listings [Line Items]      
Title of 12(b) Security Units, each consisting of one Class A ordinary share, $0.0001 par value, and one-half of one redeemable warrant    
Trading Symbol GPACU    
Security Exchange Name NASDAQ    
Class A Ordinary Shares [Member]      
Entity Listings [Line Items]      
Title of 12(b) Security Class A ordinary shares included as part of the units    
Trading Symbol GPAC    
Security Exchange Name NASDAQ    
Entity Common Stock, Shares Outstanding   23,660,000  
Redeemable Warrants [Member]      
Entity Listings [Line Items]      
Title of 12(b) Security Redeemable warrants included as part of the units, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50    
Trading Symbol GPACW    
Security Exchange Name NASDAQ    
Class B Ordinary Shares [Member]      
Entity Listings [Line Items]      
Entity Common Stock, Shares Outstanding   5,750,000