{"cik":2098712,"taxonomy":"us-gaap","tag":"EarningsPerShareBasic","label":"Earnings Per Share, Basic","description":"The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.","entityName":"GigCapital9 Corp.","units":{"USD/shares":[{"start":"2025-10-29","end":"2025-12-31","val":-0.01,"accn":"0001193125-26-134550","fy":2025,"fp":"FY","form":"10-K","filed":"2026-03-31","frame":"CY2025Q4"}]}}