Document and Entity Information Document Type Document Quarterly Report Document Period End Date Document Transition Report Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security No Trading Symbol Flag Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag CONDENSED CONSOLIDATED BALANCE SHEETS Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets: Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Investments held in physical commodities, such as gold, silver, platinum, crude oil, coal, sugar, rice, wheat, classified as current. Investment in Physical Commodities, Current Gold and silver rounds/bullion Inventory, Net Inventories Total Prepaid taxes Prepaid taxes Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Total Assets, Current Total current assets Property, Plant and Equipment, Net Property, plant and mine development, net Total Carrying amount as of the balance sheet date of inventories representing ore that has been mined and placed on the leach pad, where minerals can be extracted, not expected to be converted to cash, sold or exchanged within the normal operating cycle. Inventory Leach Pad, Noncurrent Leach pad inventories Leach pad Other Assets, Noncurrent Other non-current assets Assets Total assets Liabilities and Equity [Abstract] LIABILITIES AND SHAREHOLDERS' EQUITY Other Current Liabilities Current liabilities: Accounts Payable, Current Accounts payable Finance Lease, Liability, Current Less: current portion Finance lease liabilities, current Other Liabilities, Current Other current liabilities Total Liabilities, Current Total current liabilities Finance Lease, Liability, Noncurrent Long-term portion of minimum payments Finance lease liabilities, net of current portion Asset Retirement Obligations, Noncurrent Asset retirement obligations Liabilities Total liabilities Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Shareholders' equity: Preferred Stock, Value, Issued Preferred stock - $0.01 par value, 20,000,000 shares authorized and nil outstanding at March 31, 2026 and December 31, 2025 Common Stock, Value, Issued Common stock - $0.01 par value, 200,000,000 shares authorized and 27,189,528 shares outstanding at March 31, 2026 and 24,375,209 shares outstanding at December 31, 2025 Additional Paid in Capital Additional paid-in capital Retained Earnings (Accumulated Deficit) Accumulated deficit Stockholders' Equity Attributable to Parent Fortitude shareholders' equity Equity, Attributable to Noncontrolling Interest Noncontrolling interest Equity, Including Portion Attributable to Noncontrolling Interest Balance, at End of period Balance, at Beginning of period Total shareholders' equity Liabilities and Equity Total liabilities and shareholders' equity Preferred Stock, Par or Stated Value Per Share Preferred stock, par value (in dollars per share) Preferred Stock, Shares Authorized Preferred stock, authorized (in shares) Preferred Stock, Shares Outstanding Preferred stock, outstanding (in shares) Common Stock, Par or Stated Value Per Share Common stock, par value (in dollars per share) Common Stock, Shares Authorized Common stock, authorized (in shares) Common Stock, Shares, Outstanding Common stock, outstanding (in shares) Boolean flag that is true only when shares issued is not disclosed Common Stock Shares Issued Not Disclosed Common stock shares issued not disclosed CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Statement [Table] Statement [Line Items] Revenue from Contract with Customer, Excluding Assessed Tax Sales, net Total sales, net Cost of Goods and Services Sold [Abstract] Mine cost of sales: Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization Production costs Cost, Depreciation, Amortization and Depletion Depreciation and amortization Environmental Remediation Expense Reclamation and remediation Reclamation and remediation accretion Cost of Goods and Services Sold Total mine cost of sales Gross Profit Mine gross profit Costs and Expenses [Abstract] Costs and expenses: General and Administrative Expense General and administrative expenses Mining Exploration Expense Mining Exploration Expense Exploration expenses The aggregate amount of expenses relating to facilities and mine construction. Facilities And Mine Construction Facilities and mine construction Nonoperating Income (Expense) Other expense (income), net Total other expense (income), net Costs and Expenses Total costs and expenses Income (Loss) Attributable to Parent, before Tax (Loss) income before income and mining taxes Income Tax Expense (Benefit) Mining and income tax expense (benefit) Mining and income tax expense Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income (loss) Net (loss) income Net (loss) income Net Income (Loss) Attributable to Noncontrolling Interest Net loss (income) attributable to noncontrolling interest Net (loss) income attributable to Fortitude Shareholders Net (loss) income attributable to Fortitude Shareholders Earnings Per Share, Basic and Diluted [Abstract] Net (loss) income per common share attributable to Fortitude Shareholders: Net (loss) income per share attributable to Fortitude Shareholders: Earnings Per Share, Basic Basic (in dollars per share) Net (loss) income per share attributable to Fortitude Shareholders, Basic Earnings Per Share, Diluted Diluted (in dollars per share) Net (loss) income per share attributable to Fortitude Shareholders, Diluted Weighted Average Number of Shares Outstanding, Diluted [Abstract] Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Basic Basic (in shares) Basic weighted average shares of common stock outstanding Weighted Average Number of Shares Outstanding, Diluted Diluted (in shares) Diluted weighted average common shares outstanding CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY Equity Components [Axis] Equity Component [Domain] Common shares Common shares Additional Paid-in Capital Additional Paid-in Capital Accumulated Deficit (Accumulated Deficit) Retained Earnings Noncontrolling Interest [Member] Noncontrolling Interest Increase (Decrease) in Stockholders' Equity [Roll Forward] Shares, Outstanding Balance, at End of period (in shares) Balance, at Beginning of period (in shares) Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Stock-based compensation Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Stock-based compensation (in shares) Stock Issued During Period, Value, New Issues Issuance of stock, net of issuance costs Stock Issued During Period, Shares, New Issues Issuance of stock, net of issuance costs (in shares) Noncontrolling Interest, Increase from Subsidiary Equity Issuance Contribution to JV Stock Issued During Period, Value, Restricted Stock Award, Gross Common stock issued for vested restricted stock units Stock Issued During Period, Shares, Restricted Stock Award, Gross Common stock issued for vested restricted stock units (in shares) Common stock issued for vested restricted stock units (in shares) Dividend Dividends Dividends Stock Issued During Period, Value, Stock Options Exercised Stock options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock options exercised (in shares) CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net (loss) income to net cash from operating activities: Depreciation, Depletion and Amortization Depreciation and amortization Share-based Payment Arrangement, Noncash Expense Stock-based compensation Asset Retirement Obligation Expense Asset Retirement Obligation Expense Asset Retirement Obligation Amount of unrealized gain (loss) on gold and silver investment. Unrealized gain on gold and silver rounds bullion Unrealized gain on gold and silver rounds/bullion Other Noncash Income (Expense) Other operating adjustments Increase (Decrease) in Operating Assets [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Accounts Receivable Accounts receivable Increase (Decrease) in Inventories Inventories Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other current assets Increase (Decrease) in Other Noncurrent Assets Other non-current assets Increase (Decrease) in Accounts Payable and Accrued Liabilities Accounts payable and other accrued liabilities Net Cash Provided by (Used in) Operating Activities Net cash used in operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities: Payments to Acquire Property, Plant, and Equipment Capital expenditures Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities: Payments of Dividends Dividends paid Proceeds from Issuance of Private Placement Issuance of common stock for Private Placement Finance Lease, Principal Payments Repayment of finance leases Financing cash flows from finance leases Net Cash Provided by (Used in) Financing Activities Net cash provided by (used in) financing activities Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents at end of period Cash and cash equivalents at beginning of period Supplemental Cash Flow Information [Abstract] Supplemental Cash Flow Information Interest Paid, Excluding Capitalized Interest, Operating Activities Interest expense paid Noncash Investing and Financing Items [Abstract] Non-cash investing and financing activities: Increase Decrease In Accrued Capital Expenditures Increase Decrease In Accrued Capital Expenditures Change in capital expenditures in accounts payable Basis of Presentation of Financial Statements Business Description and Basis of Presentation [Text Block] Basis of Presentation of Financial Statements New Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Text Block] New Accounting Pronouncements Revenue Revenue from Contract with Customer [Text Block] Revenue Gold and Silver Rounds/Bullion Investment Holdings [Text Block] Gold and Silver Rounds/Bullion Inventories Inventory Disclosure [Text Block] Inventories Income Taxes Income Tax Disclosure [Text Block] Income Taxes Prepaid Expenses and Other Current Assets Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] Prepaid Expenses and Other Current Assets Property, Plant and Mine Development, net Property, Plant and Equipment Disclosure [Text Block] Property, Plant and Mine Development, net Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Other Current Liabilities Asset Retirement Obligation Asset Retirement Obligation Disclosure [Text Block] Asset Retirement Obligation Leases The entire disclosure of information about leases. Lease Disclosure [Text Block] Leases Other Expense (Income), Net Other Nonoperating Income and Expense [Text Block] Other Expense (Income), Net Net (Loss) Income per Common Share Attributable to Fortitude Shareholders Earnings Per Share [Text Block] Net (Loss) Income per Common Share Attributable to Fortitude Shareholders Fair Value Measurement Fair Value Disclosures [Text Block] Fair Value Measurement Stock-Based Compensation Share-based Payment Arrangement [Text Block] Stock-Based Compensation Shareholders' Equity Stockholders' Equity Note Disclosure [Text Block] Shareholders' Equity Basis of Accounting, Policy [Policy Text Block] Basis of Presentation Segment Reporting, Policy [Policy Text Block] Operating Segments and Related Disclosures Disclosure of accounting policy for non-controlling interest. Noncontrolling Interest Disclosure, Policy [Policy Text Block] Noncontrolling Interests Revenue from External Customers by Products and Services [Table Text Block] Schedule of company's net sales disaggregated by source Investment Holdings, Other than Securities [Table Text Block] Summary of investment holdings Schedule of Inventory, Current [Table Text Block] Schedule of current inventories Tabular disclosure of the carrying amounts of prepaid expenses and other current assets. Schedule of Prepaid Expenses and Other Current Assets [Table Text Block] Schedule of prepaid expenses and other current assets Property, Plant and Equipment [Table Text Block] Schedule of property, plant and mine development Other Current Liabilities [Table Text Block] Schedule of other current liabilities Schedule of Change in Asset Retirement Obligation [Table Text Block] Schedule of asset retirement obligation Finance Lease, Liability, Fiscal Year Maturity [Table Text Block] Schedule of finance lease maturities The tabular disclosure of cash flow information about leases. Schedule Of Lease Cash Flow Information [Table Text Block] Schedule of supplemental cash flow information of leases Schedule of Other Nonoperating Income (Expense) [Table Text Block] Schedule of other expense (income), net Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of basic and diluted net (loss) income per common share Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of assets and liabilities measured at fair value Unrealized Gain (Loss) on Investments [Table Text Block] Schedule of gains and losses related to changes in the fair value Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Schedule of stock-based compensation expense Number of Reportable Segments Number of reportable segments Number of Operating Segments Number of operating segments Noncontrolling Interest [Table] Ownership [Axis] Ownership [Domain] Represents the member information pertaining to East Camp Douglas, LLC. East Camp Douglas, LLC [Member] East Camp Douglas, LLC