v3.26.1
Cover Page - shares
 3 Months Ended
Mar. 31, 2026
May 04, 2026
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 001-43132  
Entity Registrant Name ARMADA ACQUISITION CORP. III  
Entity Tax Identification Number 98-1885131  
Document Period End Date Mar. 31, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Entity Central Index Key 0002092897  
Current Fiscal Year End Date --09-30  
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  
Entity Incorporation, State or Country Code E9  
Entity Address, Address Line One 1760 Market Street  
Entity Address, Address Line Two Suite 602  
Entity Address, City or Town Philadelphia  
Entity Address, State or Province PA  
Entity Address, Postal Zip Code 19103  
City Area Code 212  
Local Phone Number 543-6886  
Units, Each Consisting Of One Class A Ordinary Share, Par Value 0.0001 Per Share, And OneHalf Of One Redeemable Warrant [Member]    
Document Information [Line Items]    
Title of 12(b) Security Units, each consisting of one Class A ordinary share, par value $0.0001 per share, and one-half of one redeemable warrant  
Trading Symbol AACIU  
Security Exchange Name NASDAQ  
Class A Ordinary Shares, Par Value 0.0001 Per Share, Included As Part Of The Units [Member]    
Document Information [Line Items]    
Title of 12(b) Security Class A ordinary shares, par value $0.0001 per share, included as part of the units  
Trading Symbol AACI  
Security Exchange Name NASDAQ  
Warrants Included As Part Of The Units, Each Whole Warrant Exercisable For One Class A Ordinary Share At An Exercise Price Of 11.50 [Member]    
Document Information [Line Items]    
Title of 12(b) Security 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 AACIW  
Security Exchange Name NASDAQ  
Common Class A [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   25,522,000
Common Class B [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   8,507,834