{"cik":1918102,"taxonomy":"us-gaap","tag":"LesseeOperatingLeaseLiabilityPaymentsDue","label":"Lessee, Operating Lease, Liability, to be Paid","description":"Amount of lessee's undiscounted obligation for lease payment for operating lease.","entityName":"Deep Fission, Inc.","units":{"USD":[{"end":"2026-03-31","val":70834,"accn":"0001104659-26-057835","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-08"}]}}