v3.26.3
Cover
Sep. 22, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Sep. 22, 2026
Entity File Number 005-95930
Entity Registrant Name BEACON TOPCO, INC.
Entity Central Index Key 0002094256
Entity Tax Identification Number 41-2339925
Entity Incorporation, State or Country Code DE
Entity Address, Address Line One 20400 Century Boulevard
Entity Address, Address Line Two Suite 210
Entity Address, City or Town Germantown
Entity Address, State or Province MD
Entity Address, Country US
Entity Address, Postal Zip Code 20874
City Area Code 443
Local Phone Number 917-0966
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company true
Elected Not To Use the Extended Transition Period false