Cover [Abstract] Entity Registrant Name Entity Central Index Key Document Type Amendment Flag Current Fiscal Year End Date Entity Small Business Entity Shell Company Entity Emerging Growth Company Entity Current Reporting Status Document Period End Date Entity Filer Category Document Fiscal Period Focus Document Fiscal Year Focus Entity Common Stock Shares Outstanding Document Quarterly Report Document Transition Report Entity File Number Entity Incorporation State Country Code Entity Tax Identification Number Entity Address Address Line 1 Entity Address Address Line 2 Entity Address City Or Town Entity Address State Or Province Entity Address Postal Zip Code City Area Code Local Phone Number Security 12b Title Trading Symbol Security Exchange Name Entity Interactive Data Current CONDENSED CONSOLIDATED BALANCE SHEETS Assets Current assets: Cash and cash equivalents Short-term investments Investments in marketable equity securities, at fair value Prepaid expenses and other current assets Total current assets [Assets, Current] Mineral properties Restricted cash - mineral property reclamation bonds Other assets Total assets [Assets] Liabilities and Shareholders' Equity Current liabilities: Accounts payable Operating lease liability Total current liabilities [Liabilities, Current] Long-term liabilities: Asset retirement obligation and reclamation liabilities Total long-term liabilities [Liabilities, Noncurrent] Commitments and contingencies (Note 9) Shareholders' equity: Preferred stock, $0.01 par value, authorized 10,000,000 shares (none issued and outstanding at June 30, 2026 and December 31, 2025) Common stock, $0.01 par value, authorized 200,000,000 shares (94,684,463 and 90,901,324 shares, respectively, issued and outstanding at June 30, 2026 and December 31, 2025) Additional paid-in capital Accumulated deficit Total shareholders' equity [Equity, Attributable to Parent] Total liabilities and shareholders' equity [Liabilities and Equity] Preferred stock, par value Preferred stock, shares authorized Preferred stock, shares issued Preferred stock, shares outstanding Common stock, par value Common stock, shares authorized Common stock, shares issued Common stock, shares outstanding CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) Operating expense: Exploration expense Depreciation General and administrative Total operating expense [Operating Expenses] Other income (loss) Interest and dividend income Loss on derivative instruments Realized and unrealized gain on marketable equity securities Total other income (loss) [Other Nonoperating Income (Expense)] Net loss [Net Income (Loss) Attributable to Parent] Loss per common share: Basic and diluted Weighted average shares outstanding: Basic and diluted. CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Operating activities: Net loss [Net Income (Loss), Including Portion Attributable to Noncontrolling Interest] Adjustments to reconcile net loss to net cash used in operating activities: Depreciation Amortization of right of use lease asset Realized and unrealized gain on marketable equity securities Loss on derivative instruments [Gain (Loss) on Sale of Derivatives] Stock-based compensation expense Changes in operating assets and liabilities: Prepaid expenses and other current assets [Increase (Decrease) in Prepaid Expense and Other Assets] Accounts payable and other current liabilities Net cash used in operating activities [Cash Provided by (Used in) Operating Activity, Including Discontinued Operation] Investing activities: Purchase of short-term investments, net [Payments to Acquire Short-Term Investments] Cash from the sale of marketable equity securities Cash paid for settlement of derivative instruments [Cash paid for settlement of derivative instruments] Net cash used by investing activities [Cash Provided by (Used in) Investing Activity, Including Discontinued Operation] Financing activities: Issuance of common stock ATM - net of issuing costs Issuance of common stock Private Placement - net of issuing costs Issuance of common stock upon exercise of stock options Net cash provided by financing activities [Cash Provided by (Used in) Financing Activity, Including Discontinued Operation] Net increase in cash, cash equivalents and restricted cash [Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation] Cash, cash equivalents and restricted cash, beginning of period [Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation] Cash, cash equivalents and restricted cash, end of period Insider Trading Arrangements [Line Items] Rule 10b5-1 Arrangement Adopted [Flag] Rule 10b5-1 Arrangement Terminated [Flag] Non-Rule 10b5-1 Arrangement Adopted [Flag] Non-Rule 10b5-1 Arrangement Terminated [Flag] Business and Significant Accounting Policies Business and Significant Accounting Policies Significant Accounting Policies [Text Block] Mineral Properties Mineral Properties Mineral Industries Disclosures [Text Block] Marketable Equity Securities Marketable Equity Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Leases Leases Lessee, Operating Leases [Text Block] Other Assets Other Assets Other Assets Disclosure [Text Block] Fair Value of Financial Instruments Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Derivative Instruments Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Income Taxes Income Taxes Income Tax Disclosure [Text Block] Commitments and Contingencies Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Employee Stock Compensation Plans Employee Stock Compensation Plans Share-Based Payment Arrangement [Text Block] Shareholders Equity Shareholders' Equity Adopted accounting pronouncements Risks and Uncertainties Financial reporting Cash equivalents Money market funds Segment reporting Earnings per share Business and company formation Schedule of investment in mineral property Schedule of exploration expense Schedule of marketable equity securities Schedule of marketable securities and adjustment to fair value Schedule of changes in marketable equity securities Schedule of realized and unrealized (loss) gain on marketable equity securities Schedule of other assets Schedule of financial assets and liabilities measured at fair value Schedule Of Shareholders' Equity Money market fund Cash and cash equivalents held in brokerage accounts and foreign banks Potentially dilutive shares related to outstanding common stock options Statement [Table] Statement [Line Items] Long-Lived Tangible Asset [Axis] Related Party Transaction [Axis] Cat Creek Project (Colorado - US) Lik project (Alaska - US) Golden Crest (South Dakota - US) [Member] Bright Angel Project (Colorado - US) [Member] Mineral Properties Geologic and field expenses Administrative Total exploration costs Reclamation liability Asset Retirement Obligation Related Party Transactions By Related Party Axis Sale of Stock [Axis] Vendetta Mining Corp. [Member] Vox Royalty Corp. [Member] Marketable equity securities at fair value Shares Marketable equity securities at cost Cumulative unrealized loss on marketable equity securities [Cumulative unrealized loss on marketable equity securities] Marketable equity securities at fair value Cost of marketable equity securities sold Realized gain on marketable equity securities sold Gross proceeds from the sale of marketable equity securities sold Net gain on marketable equity securities Change in marketable equity securities at fair value Unrealized loss on marketable equity securities Realized gain on marketable equity securities sold [Realized gain on marketable equity securities sold] Net gain on marketable equity securities [Net gain on marketable equity securities] Kinross Calls [Member] Common stock shares sold Gain on sale of common stock shares Gross proceeds from common stock shares sale Settlement amount Net proceeds from sale after derivative settlement Business Interruption Loss Axis WR Lease [Member] Non-cash lease amortization of right of use lease assets expense recognized Discount rate Cash lease payments Furniture and Fixtures [Member] Right of Use Office Lease Asset [Member] Exploration Bonds and Other Assets [Member] Total Other Assets [Member] Other assets Fair Value Hierarchy and NAV [Axis] Level 1 [Member] Level 2 [Member] Level 3 [Member] Assets Assets, Fair Value Disclosure [Abstract] Marketable equity securities Short-term investments Solitario [Member] Unrecognized loss [Loss on Sale of Investments] Unrecognized loss Proceeds from sale of covered calls Lik Project and Golden Crest Project Asset retirement obligation Financial Instrument Axis Plan Name Axis Stock Option 2023 Plan 2013 Plan [Member] Stock-based compensation expense [Share-Based Payment Arrangement, Expense] Unrecognized stock option compensation cost related to non-vested options Unrecognized stock option compensation cost related to non-vested options, period of recognition Common stock, capital shares reserved for future issuance Stock option outstanding Number expired unexercised shares Stock options, exercise prices Options granted Proceeds from stock options exercised Options, vested and exercisable price per share amount Options, vested and exercisable Aggregate intrinsic value, granted Aggregate intrinsic value Average remaining contractual life of Solitario's outstanding options Common Stocks [Member] Additional Paid-in Capital [Member] Accumulated Deficit [Member] Beginning Balance, Amount Stock-based compensation expense [APIC, Share-Based Payment Arrangement, Increase for Cost Recognition] Issuance of shares - option Exercises Issuance Of Shares - ATM amount Issuance of shares- private placement amounts Net Loss Ending Balance, Amount Beggining Balance, Shares [Shares, Issued] Issuance of shares- option exercises, shares Issuance of shares- private placement shares Issuance of shares - ATM shares Ending Balance, Shares Stock Purchase Agreement [Member] ATM Agreement [Member] Average price Proceeds From Sales Of Shares Sale of common stock shares Net proceeds from sale of common stock shares Legal and regulatory expenses Commission Rate