XML 12 R1.htm IDEA: XBRL DOCUMENT v3.25.2
Document And Entity Information - shares
 6 Months Ended
Jun. 30, 2025
Aug. 08, 2025
Document Information [Line Items]    
Entity Central Index Key 0002028516  
Entity Registrant Name Archimedes Tech SPAC Partners II Co.  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Fiscal Period Focus Q2  
Document Fiscal Year Focus 2025  
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-42514  
Entity Incorporation, State or Country Code E9  
Entity Address, Address Line One 2093 Philadelphia Pike #1968  
Entity Address, City or Town Claymont  
Entity Address, State or Province DE  
Entity Address, Postal Zip Code 19703  
City Area Code 725  
Local Phone Number 312-2430  
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 Common Stock, Shares Outstanding   29,590,000
Warrant [Member]    
Document Information [Line Items]    
Title of 12(b) Security Warrants  
Trading Symbol ATIIW  
Security Exchange Name NASDAQ  
Common Stock [Member]    
Document Information [Line Items]    
Title of 12(b) Security Ordinary Shares  
Trading Symbol ATII  
Security Exchange Name NASDAQ  
Units [Member]    
Document Information [Line Items]    
Title of 12(b) Security Units  
Trading Symbol ATIIU  
Security Exchange Name NASDAQ