{"cik":1918102,"taxonomy":"us-gaap","tag":"OperatingLeaseLiability","label":"Operating Lease, Liability","description":"Present value of lessee's discounted obligation for lease payments from operating lease.","entityName":"DEEP FISSION, INC.","units":{"USD":[{"end":"2026-03-31","val":59567,"accn":"0001104659-26-057835","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-08"}]}}