v3.25.4

Business and Summary of Significant Accounting Policies (Policies) | 12 Months Ended
--- | ---
Dec. 31, 2025
Business and Summary of Significant Accounting Policies |
Business and company formation | Solitario Resources Corp. (“Solitario,” or the “Company”) is smaller reporting company as defined by rules issued by the United States Securities and Exchange Commission (“SEC”). Solitario was incorporated in the state of Colorado on November 15, 1984 as a wholly-owned subsidiary of Crown Resources Corporation. In July 1994, Solitario became a publicly traded company on the Toronto Stock Exchange (the “TSX”) through its initial public offering. Solitario has been actively involved in mineral exploration since 1993. Solitario’s primary business is to acquire exploration mineral properties or royalties and/or discover economic deposits on its mineral properties and advance these deposits, either on its own or through joint ventures, up to the development stage. At or prior to development, Solitario would likely attempt to sell its mineral properties, pursue their development either independently or through a joint venture with a partner that has expertise in mining operations, or create a royalty with a third party that would continue to advance the property. Solitario has never developed a property. Solitario is primarily focused on the acquisition and exploration of precious metal, zinc and other base metal exploration mineral properties. In addition to focusing on its mineral exploration properties and the evaluation of mineral properties for acquisition, Solitario from time to time also evaluates potential strategic transactions for the acquisition of new precious and base metal properties and assets with exploration potential or business combinations that Solitario determines to be favorable to Solitario. Solitario has recorded revenue in the past from the sale of mineral properties, including the sale of certain mineral royalties. Revenues and / or proceeds from the sale or joint venture of properties or assets, although potentially significant when they occur, have not been a consistent annual source of cash and would only occur in the future, if at all, on an infrequent basis. Solitario currently considers its carried interest in the Florida Canyon zinc project in Peru (the “Florida Canyon project”), its interest in the Lik zinc project in Alaska (the “Lik project”), and its Golden Crest project in South Dakota (the “Golden Crest project”) to be its core mineral property assets. Nexa Resources, Ltd. (“Nexa”), Solitario’s joint venture partner, is continuing the exploration and furtherance of the Florida Canyon Project and Solitario is monitoring progress at the Florida Canyon Project. Solitario is working with its 50% joint venture partner in the Lik Project, Teck American Incorporated, a wholly owned subsidiary of Teck Resources Limited (both companies are referred to as “Teck”), to further the exploration and evaluate potential development plans for the Lik project. In addition, Solitario has two early-stage projects, the Cat Creek project in Colorado (the “Cat Creek project”) and the Bright Angel project in Colorado (the “Bright Angel project”) acquired by Solitario in the third quarter of 2025. Solitario is conducting mineral exploration on its Golden Crest project, the Cat Creek project and the Bright Angel project on its own. As of December 31, 2025, Solitario has balances of cash and short-term investments that Solitario anticipates using, in part, to further the development of the Florida Canyon project, the Lik project, the Golden Crest project as well as its Cat Creek and Bright Angel projects, and to potentially acquire additional mineral property assets. The fluctuations in precious metal and other commodity prices contribute to a challenging environment for mineral exploration and development, which has created opportunities as well as challenges for the potential acquisition of early-stage and advanced mineral exploration projects or other related assets at potentially attractive terms.
Financial reporting | The consolidated financial statements include the accounts of Solitario and its wholly owned subsidiaries, the most significant of which are Zazu Metals Corporation, Zazu Metals (AK) Corp., and Minera Solitario Peru, S.A. All significant intercompany accounts and transactions have been eliminated in consolidation. The consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America ("generally accepted accounting principles") and are expressed in US dollars.
Revenue recognition | Solitario’s policy is to recognize revenue from the sale of its exploration mineral properties (those without reserves) on a property-by-property basis, computed as the cash received and / or collectable receivables less any capitalized cost. Payments received for the sale of exploration property interests that are less than the properties cost are recorded as a reduction of the related property's capitalized cost. In addition, Solitario’s policy is to recognize revenue on any receipts of joint venture property payments in excess of its capitalized costs on a property that Solitario may lease to another mining company. Solitario has not recorded revenue from the sale of exploration mineral properties or joint venture property payments during 2025 or 2024.
Use of estimates | The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Some of the more significant estimates included in the preparation of Solitario's financial statements pertain to: (i) the recoverability of its mineral properties related to its mineral exploration properties and their future exploration potential; (ii) the fair value of stock option grants to directors, officers, employees and consultants; and (iii) the ability of Solitario to realize its deferred tax assets.
Cash and cash equivalents | Cash equivalents generally include investments securities with original maturities of three months or less when purchased. Cash equivalents at December 31, 2025 include approximately $38,000 held in brokerage accounts and foreign banks, which are not covered under the Federal Deposit Insurance Corporation (“FDIC”) rules for the United States.
Short-term investments in money market funds | Solitario invests in money market funds that seek to maintain a stable net asset value. These funds invest in high-quality, short-term, diversified money market instruments, short-term treasury bills, federal agency securities, certificates of deposits, and commercial paper. Solitario includes its money market funds in short-term investments. Solitario believes the redemption value of these funds is likely to be the fair value, which is represented by the net asset value. Redemption is permitted daily without written notice. Solitario’s money market funds of $7,573,000 and $4,523,000, respectively, at December 31, 2025 and 2024 are included in short-term investments.
Restricted Cash | Solitario’s restricted cash represents investments in certificates of deposit and are restricted primarily for reclamation funding or surety bonds. Restricted cash and cash equivalents balances are carried at fair value. Non-current restricted cash is reported in a separate line on the consolidated balance sheets and totaled $230,000 at December 31, 2025 and 2024. Cash, excluding restricted cash, at December 31, 2025 and 2024 was $82,000 and $81,000, respectively.
Mineral properties | Solitario expenses all exploration costs incurred on its mineral properties prior to the establishment of proven and probable reserves through the completion of a feasibility study. Initial acquisition costs of its mineral properties are capitalized. Solitario regularly performs evaluations of its mineral properties to assess the recoverability and/or the residual value of its investments in these assets. All long-lived assets are reviewed for impairment whenever events or circumstances change which indicate the carrying amount of an asset may not be recoverable, utilizing established guidelines based upon undiscounted future net cash flows from the asset or upon the determination that certain exploration properties do not have sufficient potential for economic mineralization.
Derivative instruments | Solitario accounts for its derivative instruments in accordance with ASC 815, "Derivatives and Hedging” (“ASC 815”). Solitario previously entered into covered calls from time to time on its investment in Kinross Gold Corporation (“Kinross”) marketable equity securities. Solitario has not designated its covered calls as hedging instruments and any changes in the fair value of the covered calls are recognized in the statements of operations in the period of the change as gain or loss on derivative instruments.
Fair value | Financial Accounting Standards Board ASC 820, “Fair Value Measurements” (“ASC 820”) establishes a framework for measuring fair value and requires enhanced disclosures about fair value measurements. ASC 820 clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. ASC 820 also requires disclosure about how fair value is determined for assets and liabilities and establishes a hierarchy for which these assets and liabilities must be grouped, based on significant levels of inputs as follows: Level 1: Quoted prices in active markets for identical assets or liabilities; Level 2: Quoted prices in active markets for similar assets and liabilities and inputs that are observable for the asset or liability; or Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The determination of where assets and liabilities fall within this hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Solitario's short-term investments in money market investments, its marketable equity securities and any covered call options against those marketable equity securities are carried at their estimated fair value based on quoted market prices. See Note 8, “Fair Value of Financial Instruments,” below.
Marketable equity securities | Solitario's investments in marketable equity securities are carried at fair value, which is based upon quoted prices of the securities owned. Solitario records investments in marketable equity securities for investments in publicly traded marketable equity securities for which it does not exercise significant control and where Solitario has no representation on the board of directors of those companies and exercises no control over the management of those companies. The cost and realized gain or loss on marketable equity securities sold is determined by the specific identification method. Changes in fair value on Solitario’s holdings of marketable equity securities are recorded as unrealized gain or loss in the consolidated statement of operations.
Mineral property joint ventures | Solitario accounts for investments in companies and joint ventures in which we have the ability to exercise significant influence, but do not control, are accounted for under the equity method of accounting. In determining whether significant influence exists, the Company considers its participation in policy-making decisions and representation on governing bodies. Under the equity method of accounting, our share of the net earnings or losses of the investee are included in net income (loss) in the consolidated statements of operations. Solitario’s mineral property joint ventures represent cost sharing of project costs. Shared costs are expensed as incurred. Solitario does not apply equity-method accounting nor consolidate the operations of Lik or Florida Canyon joint ventures as it does not exercise significant control over these projects.
Foreign exchange | The United States dollar is the functional currency for Solitario and all of Solitario's foreign subsidiaries. Foreign currency gains and losses are included in the results of operations in the period in which they occur.
Income taxes | Solitario accounts for income taxes in accordance with ASC 740, “Income Taxes” (“ASC 740”). Under ASC 740, income tax expense or benefit are provided for the tax effects of transactions reported in the financial statements and consist of taxes currently due plus deferred taxes related to certain income and expenses recognized in different periods for financial and income tax reporting purposes. Deferred tax assets and liabilities represent the future tax return consequences of those differences, which will either be taxable or deductible when the assets and liabilities are recovered or settled. Deferred taxes are also recognized for operating losses, carryovers and tax credits that are available to offset future taxable income and income taxes, respectively. A valuation allowance is provided if it is more likely than not that some portion or all of the deferred tax assets will not be realized.
Accounting for uncertainty in income taxes | ASC 740 clarifies the accounting for uncertainty in income taxes recognized in a company's financial statements. ASC 740 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. ASC 740 also provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition. ASC 740 provides that a company's tax position will be considered settled if the taxing authority has completed its examination, the company does not plan to appeal, and it is remote that the taxing authority would reexamine the tax position in the future. These provisions of ASC 740 had no effect on Solitario's financial position or results of operations. See Note 6, “Income Taxes,” below.
Earnings per share | The calculation of basic and diluted earnings (loss) per share is based on the weighted average number of shares of common stock outstanding during the years ended December 31, 2025 and 2024. Potentially dilutive shares, consisting of outstanding common stock options of 5,565,000 and 5,348,500, respectively, exercisable for Solitario common shares were excluded from the calculation of diluted loss per share for the year ended December 31, 2025 and 2024 because the effects were anti-dilutive.
Employee stock compensation and incentive plans | Solitario classifies all of its stock options as equity options in accordance with the provisions of ASC 718, “Compensation – Stock Compensation.” Solitario calculates grant date fair value of options based upon a Black-Scholes model utilizing the vesting term of the option, the grant date historical volatility and the risk-free interest rate on the date of grant. The grant date fair value is amortized on a straight-line basis over the vesting term of the option, and the stock-based compensation is charged to the statement of operations and credited to additional-paid-in-capital. Solitario accounts for forfeitures in the year they occur. See Note 10, “Employee Stock Compensation Plans,” below.
Reclamation and asset retirement obligations | Reclamation obligations associated with Solitario’s exploration activities are recognized when an obligation is incurred, can be reasonably estimated and not concurrently remediated. Expected reclamation costs are periodically reviewed and adjusted to reflect changes related to on-going exploration activities, inflation and on-going activities that reduce potential future reclamation liabilities. Exploration reclamation liabilities on properties without asset retirement obligations are charged to expense when incurred. Solitario does not apply a discount rate to its asset retirement obligation as the estimated time frame for reclamation on its exploration projects is not currently known, as reclamation is not expected to occur until the end of project life, which would follow future development and operations, the start of which cannot be estimated or assured at this time. Additionally, no depreciation will be recorded on the related asset for the asset retirement obligation until the project goes into operation, which cannot be assured.
Segment reporting | Solitario operates as a single operating segment in accordance with FASB ASU 2023-07 Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. All financial information is presented on a consolidated basis and reviewed by Solitario’s Chief Executive Officer as the Chief Operating Decision Maker (CODM). The CODM uses consolidated net loss, as presented in the consolidated statement of operations, to assess segment performance and allocate resources. The measure of segment assets is reported on the balance sheet as total consolidated assets.
Adopted accounting pronouncements | Solitario has adopted ASU 2023-05, Business Combinations - Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement, issued by the FASB in August 2023, which clarifies the business combination accounting for joint venture formations (“ASU 2023-05”). The amendments in ASU 2023-05 seek to reduce diversity in practice that has resulted from a lack of authoritative guidance regarding the accounting for the formation of joint ventures in separate financial statements. The amendments also seek to clarify the initial measurement of joint venture net assets, including businesses contributed to a joint venture. The guidance is applicable to all entities involved in the formation of a joint venture. The amendments are effective for all joint venture formations with a formation date on or after January 1, 2025. The adoption of ASU No. 2023-05 did not have a material impact on Solitario’s consolidated financial position or results of operations and statement disclosures. The FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures in December 2023 which amended income tax disclosure requirements for the effective tax rate reconciliation and income taxes paid (“ASU 2023-09”). The amendments in ASU 2023-09 are effective for public business entities for fiscal years beginning after December 15, 2025 and may be applied prospectively for interim reporting periods. Solitario has adopted as of the first quarter of 2025 ASU No. 2023-09, which had no impact on its consolidated financial position or results of operations and statement disclosures.
Recent accounting pronouncements | The FASB issued ASU 2024-03, Income Statement – Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses(“ASU 2024-03”) in November 2024, which requires disaggregation of certain expense captions into specified categories in disclosures within the footnotes to the financial statements. Under ASU 2024-03, entities will be required to disaggregate information, in tabular format, about specific natural expense categories underlying certain income statement expense line items that are considered ‘relevant’, such as purchases of inventory, employee compensation, depreciation, and intangible asset amortization. Additionally, ASU 2024-03 requires the disclosure of selling expenses, along with how an entity defines such expenses. For public entities, the provisions within ASU 2024-03 (as further clarified through ASU No. 2025-01, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40)) are effective for the first annual reporting period beginning after December 15, 2026, and for interim reporting periods within annual reporting periods beginning after December 15, 2027. The provisions within ASU 2024-03 are required to be applied prospectively; however, they may be applied retrospectively for all comparative periods following the effective date. Solitario is currently assessing the impact the adoption of ASU 2024-03 will have on its consolidated financial position or results of operations and statement disclosures.
Risks and Uncertainties | Solitario is subject to various risks and uncertainties that are specific to the nature of its business and the exploration of its mineral properties. Solitario also faces various macro-economic risks and uncertainties, such as risks related to health epidemics, pandemics, and other outbreaks or resurgences of communicable diseases, the occurrence of natural disasters, rising geopolitical tension and instability, acts of war or terrorism, global economic uncertainty, inflationary pressures, interest rate volatility, and volatility and disruption in national and international financial markets. These risks and uncertainties could significantly disrupt Solitario’s operations and may materially and adversely affect its business and financial condition. Certain of these risks and uncertainties are discussed under the heading “Risk Factors” in Item 1A of this 2025 Annual Report and generally identified under the heading “Forward-Looking Statements.”

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for legal obligation associated with retirement of long-lived asset that results from acquisition, construction, or development or from normal operation of long-lived asset. Excludes environmental remediation liability from improper or other-than-normal operation of long-lived asset, obligation arising in connection with leased property that meets definition of lease payments or variable lease payments and from plan to sell or otherwise dispose of a long-lived asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/410-20/tableOfContent + Details
Name: | us-gaap_AssetRetirementObligationsPolicy
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for basis of accounting, or basis of presentation, used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483426/235-10-50-4 + Details
Name: | us-gaap_BasisOfAccountingPolicyPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-1 + Details
Name: | us-gaap_CashAndCashEquivalentsPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Entity's cash and cash equivalents accounting policy with respect to restricted balances. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(1)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-1 + Details
Name: | us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for credit risk. Includes, but is not limited to, policy for entering into master netting arrangement or similar agreement to mitigate credit risk of financial instrument. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 21 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-21 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 21 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-21 + Details
Name: | us-gaap_ConcentrationRiskCreditRisk
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483426/235-10-50-4 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481203/810-10-50-1 + Details
Name: | us-gaap_ConsolidationPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for its derivative instruments and hedging activities. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-8 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479693/815-10-S50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8C -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-8C Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-8 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-7 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/815/tableOfContent Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-9 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(n)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 + Details
Name: | us-gaap_DerivativesPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-2 + Details
Name: | us-gaap_EarningsPerSharePolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for determining the fair value of financial instruments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-1 + Details
Name: | us-gaap_FairValueOfFinancialInstrumentsPolicy
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for (1) transactions denominated in a currency other than the reporting enterprise's functional currency, (2) translating foreign currency financial statements that are incorporated into the financial statements of the reporting enterprise by consolidation, combination, or the equity method of accounting, and (3) remeasurement of the financial statements of a foreign reporting enterprise in a hyperinflationary economy. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/830/tableOfContent + Details
Name: | us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 20 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-20 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 19 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-19 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482525/740-10-45-25 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(h)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 17 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-17 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-9 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482525/740-10-45-28 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-1 + Details
Name: | us-gaap_IncomeTaxPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for tax positions taken in the tax return filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities and other types of contingencies related to income taxes. + References No definition available. + Details
Name: | us-gaap_IncomeTaxUncertaintiesPolicy
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for interest in an unincorporated joint venture or partnership that is included in the enterprise's financial statements using the proportionate consolidation method of accounting. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 932 -SubTopic 810 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477424/932-810-45-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 932 -SubTopic 323 -Name Accounting Standards Codification -Section 25 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477472/932-323-25-2 + Details
Name: | us-gaap_InterestInUnincorporatedJointVenturesOrPartnershipsPolicy
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for investment in financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(3)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(d)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(f)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(f)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(f)(3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 12 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-12 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 19 -Subparagraph (2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-19 + Details
Name: | us-gaap_InvestmentPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for investment classified as marketable security. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477268/942-320-50-5 + Details
Name: | us-gaap_MarketableSecuritiesPolicy
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy pertaining to new accounting pronouncements that may impact the entity's financial reporting. Includes, but is not limited to, quantification of the expected or actual impact. + References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for oil and gas property which may include the basis of such assets, depreciation methods used and estimated useful lives, the entity's capitalization policy, including its accounting treatment for costs incurred for repairs and maintenance activities, whether such asset balances include capitalized interest and the method by which such is calculated, how disposals of such assets are accounted for and how impairment of such assets is assessed and recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -SubTopic 10 -Topic 360 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482099/360-10-50-1 + Details
Name: | us-gaap_OilAndGasPropertiesPolicyPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for revenue. Includes revenue from contract with customer and from other sources. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
Name: | us-gaap_RevenueRecognitionPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for segment reporting. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 41 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-41 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-29 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-29 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-29 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 47 -Subparagraph (bb) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-47 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-29 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 54 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-54 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 36 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-36 Reference 9: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 47 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-47 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-29 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-29 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-29 + Details
Name: | us-gaap_SegmentReportingPolicyPolicyTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478671/942-235-S50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477314/942-235-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-12 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-9 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482836/275-10-55-6 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-6 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-4 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -SubTopic 10 -Topic 275 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -SubTopic 10 -Topic 275 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-1 + Details
Name: | us-gaap_UseOfEstimates
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | xpl_CompensationAndEmployeeBenefitPlansPilocyTextblock
Namespace Prefix: | xpl_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | xpl_NewAdoptedAccountingPronouncementsPolicyPolicyTextblock
Namespace Prefix: | xpl_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration