v3.26.1
Cover - USD ($)
6 Months Ended
Dec. 31, 2025
Mar. 30, 2026
Jun. 30, 2025
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Central Index Key 0002079173    
Entity File Number 001-42866    
Entity Registrant Name AMERICAN EXCEPTIONALISM ACQUISITION CORP. A    
Entity Incorporation, State or Country Code E9    
Entity Tax Identification Number 98-1871331    
Entity Address, Address Line One 506 Santa Cruz Ave    
Entity Address, Address Line Two Suite 300    
Entity Address, City or Town Menlo Park    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 94025    
City Area Code 650    
Local Phone Number 521-9007    
Title of 12(b) Security Class A ordinary shares, $0.0001 par value per share    
Trading Symbol AEXA    
Security Exchange Name NYSE    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
Entity Shell Company true    
Auditor Name WithumSmith    
Auditor Firm ID 100    
Auditor Location New York, New York    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Public Float     $ 0
Inception Date Jul. 11, 2025    
Class A ordinary shares [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   34,675,000  
Class B ordinary shares [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   14,785,714