v3.25.2
Document And Entity Information
3 Months Ended
Mar. 31, 2025
Document Information Line Items  
Entity Central Index Key 0002019804
Document Type S-4
Entity Registrant Name HCM II Acquisition Corp.
Entity Incorporation, State or Country Code E9
Entity Filer Category Non-accelerated Filer
Entity Small Business true
Entity Emerging Growth Company true
Entity Ex Transition Period false
Amendment Flag false