{"cik":2098712,"taxonomy":"us-gaap","tag":"RetainedEarningsAccumulatedDeficit","label":"Retained Earnings (Accumulated Deficit)","description":"The cumulative amount of the reporting entity's undistributed earnings or deficit.","entityName":"GigCapital9 Corp.","units":{"USD":[{"end":"2025-12-31","val":-44764,"accn":"0001193125-26-134550","fy":2025,"fp":"FY","form":"10-K","filed":"2026-03-31","frame":"CY2025Q4I"}]}}