v3.26.1
Document and Entity Information
Mar. 23, 2026
Entity Listings [Line Items]  
Document Type 8-K
Amendment Flag false
Document Period End Date Mar. 23, 2026
Entity File Number 1-42521
Entity Registrant Name ARTIUS II ACQUISITION INC.
Entity Central Index Key 0002034334
Entity Incorporation, State or Country Code E9
Entity Tax Identification Number 00-0000000
Entity Address, Address Line One 3 Columbus Circle
Entity Address, Address Line Two Suite 1609
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10019
City Area Code 212
Local Phone Number 309-7668
Entity Emerging Growth Company true
Entity Ex Transition Period false
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Common Class A [Member]  
Entity Listings [Line Items]  
Title of 12(b) Security Class A ordinary shares, par value $0.0001 per share
Trading Symbol AACB
Security Exchange Name NASDAQ
Units, each consisting of one Class A ordinary share, $0.0001 par value, one right to receive one tenth of one Class A ordinary share, and one contingent right [Member]  
Entity Listings [Line Items]  
Title of 12(b) Security Units, each consisting of one Class A ordinary share, $0.0001 par value
Trading Symbol AACBU
Security Exchange Name NASDAQ
Rights, each right entitling the holder to receive one tenth of one Class A ordinary share [Member]  
Entity Listings [Line Items]  
Title of 12(b) Security Rights, each right entitling the holder to receive one tenth of one Class A ordinary share
Trading Symbol AACBR
Security Exchange Name NASDAQ