v3.26.1
Cover
Jul. 01, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Jul. 01, 2026
Entity File Number 001-43345
Entity Registrant Name Avalanche Treasury Corporation
Entity Central Index Key 0002092446
Entity Tax Identification Number 39-4863126
Entity Incorporation, State or Country Code DE
Entity Address, Address Line One 11 W. 42nd Street 2nd Floor
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10036
City Area Code 332
Local Phone Number 240-1155
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Class A common stock, par value $0.01 per share
Trading Symbol AVAT
Security Exchange Name NASDAQ
Entity Emerging Growth Company true
Elected Not To Use the Extended Transition Period false