Accounting Policies, by Policy (Policies)	12 Months Ended
Accounting Policies, by Policy (Policies)	Jun. 30, 2017
Accounting Policies [Abstract]
Consolidation, Policy [Policy Text Block]	Principles of Consolidation. The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries: USGB, USBERM, USCAN and U.S. Global Indices, LLC. The Company, through USCAN, owns 65 percent of the issued and outstanding shares of Galileo, which represents controlling interest of Galileo. Galileo is consolidated with USCAN and the non-controlling interest in this subsidiary is included in “non-controlling interest in subsidiary” in the equity section of the Consolidated Balance Sheets. There are two primary consolidation models in U.S. GAAP, the variable interest entity (“VIE”) and voting interest entity models. The Company’s evaluation for consolidation includes whether entities in which it has an interest or from which it receives fees are VIEs and whether the Company is the primary beneficiary of any VIEs identified in its analysis. A VIE is an entity in which either (a) the equity investment at risk is not sufficient to permit the entity to finance its own activities without additional financial support or (b) the group of holders of the equity investment at risk lacks certain characteristics of a controlling financial interest. The primary beneficiary is the entity that has the obligation to absorb a majority of the expected losses or the right to receive the majority of the residual returns and consolidates the VIE on the basis of having a controlling financial interest. The Company holds variable interests in, but is not deemed to be the primary beneficiary of, certain funds it advises. The Company’s interests in these VIEs consist of the Company’s direct ownership therein and any fees earned but uncollected. In the ordinary course of business, the Company may choose to waive certain fees or assume operating expenses of the funds it advises for competitive, regulatory or contractual reasons (see Note 4 for information regarding fee waivers). The Company has not provided financial support to any of these entities outside the ordinary course of business. The Company’s risk of loss with respect to these VIEs is limited to the carrying value of its investments in, and fees receivable from, the entities. The Company does not consolidate these VIEs because it is not the primary beneficiary. The Company’s total exposure to unconsolidated VIEs, consisting of the carrying value of investment securities and receivables for fees, was $11.3 million at June 30, 2017, and $11.8 million at June 30, 2016. Since the Company is not the primary beneficiary of the funds it advises, the Company evaluated if it should consolidate under the voting interest entity model. Under the voting interest model, for legal entities other than partnerships, the usual condition for control is ownership, directly or indirectly, of more than 50 percent of the outstanding voting shares over an entity. The Company does not have control of any of the funds it advises; therefore, the Company does not consolidate any of these funds. All significant intercompany balances and transactions have been eliminated in consolidation. Certain amounts have been reclassified for comparative purposes.
Business Combinations Policy [Policy Text Block]	Business Combinations. Business combinations are accounted for under the acquisition method of accounting. Results of operations of an acquired business are included from the date of acquisition. Management estimates the fair value of the acquired assets, including identifiable intangible assets, assumed liabilities, and non-controlling interest in the acquiree based on their estimated fair values as of the date of acquisition. Any excess acquisition date fair value of the consideration transferred over fair value of the acquired net assets, if any, is recorded as “goodwill” on the Consolidated Balance Sheets. Any excess fair value of the acquired net assets over the acquisition date fair value of the consideration transferred is recorded as a gain on the Consolidated Statements of Operations.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents. Cash and cash equivalents include highly liquid investments with original maturities of three months or less.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash. Restricted cash represents cash invested in a money market account as collateral for the credit facility that is not available for general corporate use.
Investment, Policy [Policy Text Block]	Investments. The Company classifies its investments based on intent at the time of purchase and reevaluates such designation as of each reporting period date. The Company records security transactions on trade date. Realized gains (losses) from security transactions are calculated on the first-in/first-out cost basis, unless otherwise identifiable, and are recorded in earnings on the date of sale. Trading Securities. Securities that are purchased and held principally for the purpose of selling in the near term are classified as trading securities and reported at fair value. Unrealized gains and losses on these securities are included in Investment income (loss). Held-to-Maturity Securities. Debt securities that are purchased with the intent and ability to hold until maturity are classified as held-to-maturity and measured at amortized cost. The Company currently has no investments in held-to-maturity securities. Available-for-sale Securities. Securities that are neither trading securities nor held-to-maturity securities and for which the Company does not have significant influence are classified as available-for-sale securities and reported at fair value. Unrealized gains and losses on these available-for-sale securities are excluded from earnings, reported net of tax as a separate component of shareholders’ equity, and recorded in earnings when realized. The Company evaluates its available-for-sale investments for other-than-temporary decline in value on a periodic basis. This may exist when the fair value of an investment security has been below the current value for an extended period of time. When a security in the Company’s investment portfolio has an unrealized loss in fair value that is deemed to be other than temporary, the Company reduces the book value of such security to its current fair value, recognizing the credit related decline as a realized loss in the Consolidated Statements of Operations and a revised GAAP cost basis for the security is established. For available-for-sale securities with declines in value deemed other than temporary, the unrealized loss recorded net of tax in accumulated other comprehensive income (loss) is realized as a charge to net income. Other Investments. Other investments consist of equity investments in entities over which the Company is unable to exercise significant influence and which do not have readily determinable fair values. These equity investments are accounted for under the cost method of accounting and evaluated for impairment. The Company considers many factors in determining impairment, including the severity and duration of the decline in value below cost, the Company’s interest and ability to hold the security for a period of time sufficient for an anticipated recovery in value, and the financial condition and specific events related to the issuer.
Equity Method Investments [Policy Text Block]	Equity Method Investments. Investments classified as equity method consist of investments in companies in which the Company is able to exercise significant influence but not control. Under the equity method of accounting, the Company’s proportional share of investee’s underlying net income or loss is recorded as a component of “other income” with a corresponding increase or decrease to the carrying value of the investment. Distributions received from the investee reduce the Company’s carrying value of the investment. These investments are evaluated for impairment if events or circumstances arise that indicate that the carrying amount of such assets may not be recoverable. No impairment was recognized for the Company’s equity method investment during the years presented. No investments were held at June 30, 2017, or 2016 that are accounted for using the equity method.
Fair Value Measurement, Policy [Policy Text Block]	Fair Value of Financial Instruments. The financial instruments of the Company are reported on the Consolidated Balance Sheets at market or fair values or at carrying amounts that approximate fair values.
Trade and Other Accounts Receivable, Policy [Policy Text Block]	Receivables. Receivables other than notes receivable consist primarily of advisory and other fees owed to the Company by clients. Receivables also include advisory fees owed to Galileo by the funds and clients it manages. The Company also invests in notes receivable. Notes receivable are recorded in accordance with the terms of the agreement, and accrued interest is recorded when earned. Unearned fees are shown as a deduction from the related notes receivable and are amortized to interest income using the effective interest method. The Company reviews the need for an allowance for credit losses for notes and other receivables based on various factors including payment history, historical bad debt experience, existing economic conditions, aging and specific accounts identified as high risk. Uncollectible receivables, if any, are charged against the allowance when all reasonable efforts to collect the amounts due have been exhausted. The Company had no allowance for credit losses as of June 30, 2017, or 2016.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment. Fixed assets are recorded at cost. Except for Galileo, depreciation for fixed assets is recorded using the straight-line method over the estimated useful life of each asset as follows: furniture and equipment are depreciated over 3 to 10 years, and the building and related improvements are depreciated over 14 to 40 years. Galileo fixed assets, consisting of furniture, equipment and leasehold improvements, are depreciated over 2 to 5 years.
Lessee, Leases [Policy Text Block]	Leases. The Company and its subsidiaries lease equipment and office space under various leasing arrangements. Leases may be classified as either capital leases or operating leases, as appropriate. Current lease agreements are classified as operating leases and most contain renewal options. Rent expense under non-cancelable operating leases with scheduled rent increases or rent incentives is accounted for on a straight-line basis over the lease term. Build-out allowances and other such lease incentives are amortized on a straight-line basis as a reduction of rent expense over the term of the lease.
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment of Long-Lived Assets. The Company reviews property and equipment and other long-lived assets for impairment whenever events or changes in business circumstances indicate the net book values of the assets may not be recoverable. Impairment is indicated when the assets’ net book value is less than fair value of the asset. If this occurs, an impairment loss is recognized for the difference between the fair value and net book value. Factors that indicate potential impairment include: a significant decrease in the market value of the asset or a significant change in the asset’s physical condition or use. No impairments of long-lived assets were recorded during the years included in these financial statements.
Intangible Assets, Finite-Lived, Policy [Policy Text Block]	Intangible Asset. An intangible asset, consisting of a non-compete agreement, acquired in connection with the acquisition of Galileo shares effective June 1, 2014, was recorded at fair value $90,000 determined using a discounted cash flow model as of the date of acquisition. The Company determined that the non-compete agreement had a finite useful life. The Company amortized this finite-lived identifiable intangible asset on a straight-line basis over its estimated useful life of 2 years. Amortization expense totaled $0; $41,000; and $45,000 in fiscal years 2017, 2016, and 2015, respectively. Amortization expense is included in depreciation and amortization on the Consolidated Statements of Operations. The asset was fully amortized by June 30, 2017, and June 30, 2016. Management periodically evaluates the remaining useful lives and carrying values of intangible assets to determine whether events and circumstances indicate that a change in the useful life or impairment in value may have occurred. Indicators of impairment monitored by management include a decline in the level of managed assets, changes to contractual provisions underlying the intangible assets and reductions in underlying operating cash flows. Should there be an indication of a change in the useful life or impairment in value of the finite-lived intangible asset, the Company compares the carrying value of the asset and its related useful life to the projected discounted cash flows expected to be generated from the underlying managed assets over its remaining useful life to determine whether impairment has occurred. If the carrying value of the asset exceeds the discounted cash flows, the asset is written down to its fair value determined using discounted cash flows.
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]	Non-Controlling Interests. The Company reports “non-controlling interest in subsidiary” as equity, separate from parent’s equity, on the Consolidated Balance Sheets. In addition, the Company’s Consolidated Statements of Operations includes “net income (loss) attributable to non-controlling interest.”
Stockholders' Equity, Policy [Policy Text Block]	Treasury Stock. Treasury stock purchases are accounted for under the cost method. The subsequent issuances of these shares are accounted for based on their weighted-average cost basis.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Compensation. Stock-based compensation expense is measured at the grant date based on the fair value of the award, and the cost is recognized as expense ratably over the award’s vesting period.
Income Tax, Policy [Policy Text Block]	Income Taxes. The Company and its non-Canadian subsidiaries file a consolidated federal income tax return. USCAN and Galileo file separate tax returns in Canada. Provisions for income taxes include deferred taxes for temporary differences in the bases of assets and liabilities for financial and tax purposes, resulting from the use of the liability method of accounting for income taxes. The liability method requires that deferred tax assets be reduced by a valuation allowance in cases where it is more likely than not that the deferred tax assets will not be realized. The Company accounts for income taxes in accordance with ASC 740, Income Taxes. The Company’s policy is to recognize interest and penalties related to uncertain tax positions in income tax expense. As of June 30, 2017, the Company did not have any accrued interest or penalties related to uncertain tax positions. The tax years from 2013 through 2016 remain open to examination by the U.S. Federal tax jurisdictions to which the Company is subject. The tax years from 2010 through 2016 remain open to examination by the non-U.S. Federal tax jurisdictions to which the Company is subject.
Revenue Recognition Accounting Policy, Gross and Net Revenue Disclosure [Policy Text Block]	Revenue Recognition. The Company earns substantially all of its revenues from advisory and administrative fees that are calculated as a percentage of assets under management and are recorded as revenue as services are performed. Offshore advisory client contracts provide for monthly management fees, in addition to performance fees. The advisory contract for the equity funds within USGIF provides for a performance fee on the base advisory fee that are calculated and recorded monthly. Revenue shown on the Consolidated Statements of Operations is net of fee waivers.
Revenue Recognition, Dividends and Interest [Policy Text Block]	Dividends and Interest. Dividends are recorded on the ex-dividend date, and interest income is recorded on an accrual basis. Any discount between the cost and the principal amount of debt investments is amortized to interest income using the effective interest method. Both dividends and interest income are included in investment income.
Advertising Costs, Policy [Policy Text Block]	Advertising Costs. The Company expenses advertising costs as they are incurred. As of December 2015, the Company is reimbursed for certain advertising expenses related to USGIF from the distributor for USGIF. Net advertising expenditures were $135,000; $212,000; and $135,000 during fiscal years 2017, 2016, and 2015, respectively.
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Exchange. The balance sheets of certain foreign subsidiaries of the Company and certain foreign-denominated investment products are translated at the current exchange rate as of the end of the accounting period and the related income or loss is translated at the average exchange rate in effect during the period. Net exchange gains and losses resulting from balance sheet translations of foreign subsidiaries are excluded from income and are recorded in “accumulated other comprehensive income (loss)” on the Consolidated Balance Sheets. Net exchange gains and losses resulting from income or loss translations are included in income and are recorded in “investment income (loss)” on the Consolidated Statements of Operations. Investment transactions denominated in foreign currencies are converted to U.S. dollars using the exchange rate on the date of the transaction and any related gain or loss is included in “investment income (loss)” on the Consolidated Statements of Operations.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates. The preparation of the consolidated financial statements in conformity with generally accepted accounting principles requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates.
Earnings Per Share, Policy [Policy Text Block]	Earnings Per Share. The Company computes and presents earnings per share attributable to U.S. Global Investors, Inc. in accordance with ASC 260, Earnings Per Share. Basic earnings per share (“EPS”) excludes dilution and is computed by dividing net income (loss) attributable to U.S. Global Investors, Inc. by the weighted average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution of EPS that could occur if options to issue common stock were exercised. The Company has two classes of common stock with outstanding shares. Both classes share equally in dividend and liquidation preferences.
Comprehensive Income, Policy [Policy Text Block]	Accumulated Other Comprehensive Income (Loss). Accumulated other comprehensive income (loss) (“AOCI”), net of tax is reported in the Consolidated Balance Sheets and the Consolidated Statements of Shareholders’ Equity and includes the unrealized gains and losses on securities classified as available-for-sale and foreign currency translation adjustments.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Accounting Pronouncements Adopted During the Period In August 2014, the FASB issued Accounting Standards Update (“ASU”) 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). This update requires an entity’s management to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued when applicable). When conditions or events raise substantial doubts about an entity’s ability to continue as a going concern, management shall disclose: i) the principal conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern; ii) management’s evaluation of the significance of those conditions or events in relation to the entity’s ability to meet its obligations; and iii) management’s plans that are intended to mitigate the conditions or events - and whether or not those plans alleviate the substantial doubt about the entity’s ability to continue as a going concern. ASU 2014-15 was effective for the annual period ending after December 15, 2016, and for annual period and interim periods thereafter. Early application was permitted. The Company adopted this guidance in the fourth quarter of the fiscal year ended June 30, 2017, with no impact on its consolidated financial statements. In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis (“ASU 2015-02”), which amended the consolidation requirements in ASC 810, Consolidation. This standard modified existing consolidation guidance for reporting organizations that are required to evaluate whether they should consolidate certain legal entities. ASU 2015-02 was effective for fiscal years and interim periods within those years beginning after December 15, 2015, and required either a retrospective or a modified retrospective approach to adoption. The Company adopted this standard on a modified retrospective approach effective July 1, 2016. The adoption did not result in any change in consolidated entities. See further discussion of the Company’s analysis for consolidation in Note 2, Significant Accounting Policies - Principles of Consolidation. In May 2015, the FASB issued ASU 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) (“ASU 2015-07”). ASU 2015-07 removed the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the NAV per share practical expedient. The update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2015, and required the retrospective adoption approach. The Company adopted this standard for the September 30, 2016, financial statements on a retrospective basis and modified the presentation of the fair value hierarchy tables included in the notes to financial statements. In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes (“ASU 2015-17”). ASU 2015-17 required entities to present deferred tax assets and deferred tax liabilities as noncurrent in a classified balance sheet. Netting by tax jurisdiction is still required under the new guidance. The update was effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods, and early adoption was permitted. Entities were permitted to apply the amendments either prospectively or retrospectively. The Company early adopted this guidance effective September 30, 2016, on a prospective basis. As a full reserve valuation allowance was recorded for deferred tax balances, adoption of the guidance did not result in any changes or reclassifications in the Consolidated Balance Sheets as of September 30, 2016. No prior periods were retrospectively adjusted. Accounting Pronouncements Not Yet Adopted In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. ASU 2014-09 defines a five-step process to achieve this core principle and, in doing so, more judgment and estimates may be required within the revenue recognition process than are required under existing U.S. GAAP. The standard is effective for annual periods beginning after December 15, 2017, and interim periods therein, using either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures). Early adoption is permitted, but the Company currently does not expect to implement the new standard before the required effective date. Additional ASUs have been issued to clarify certain aspects of ASU 2014-09. ASU 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net) amends ASU 2014-09 to clarify that an entity should evaluate whether it is the principal or the agent for each specified good or service promised in a contract with a customer. ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing, clarifies the guidance related to identifying performance obligations and the licensing guidance in ASU 2014-09. ASU No. 2016-20, Technical Corrections and Improvements in Topic 606 Revenue from Contracts with Customers, provides additional clarification to a number of topics addressed in ASU No. 2014-09. These ASUs are effective in conjunction with the adoption of ASU 2014-09. The Company expects to adopt the guidance in the first quarter of fiscal year 2019 on a modified retrospective basis. The Company is in the process of evaluating its contracts using the prescribed five-step process to determine the impact of this standard and does not currently expect the adoption to have a material impact on its consolidated balance sheets or statements of operations. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). ASU 2016-01 amends the guidance on the classification and measurement of investments in equity securities. It also amends certain presentation and disclosure requirements. Under the amended guidance, all equity investments in unconsolidated entities (other than those accounted for using the equity method of accounting) will generally be measured at fair value through earnings. There will no longer be an available-for-sale classification (changes in fair value reported in other comprehensive income) for equity securities with readily determinable fair values. ASU 2016-01 is effective for public business entities for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. As indicated, when this standard is adopted, changes in the fair value of the Company’s investments securities classified as available-for-sale will no longer be reported through other comprehensive income, but rather through earnings, causing investment income (loss) to be more volatile. The Company is currently evaluating other potential impacts of this standard on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 introduces a lessee model that brings most leases on the balance sheet by recording a lease asset and a lease liability. The new guidance will be effective for public business entities for annual periods beginning after December 15, 2018, and interim periods therein. Early adoption is permitted. The Company’s current leases are primarily for equipment and for office space for the Canadian subsidiary. The Company does not expect that adoption will have a material impact on its consolidated statements of operations because its leases are currently classified as operating leases, which under the guidance will continue to be recognized as expense on a straight-line basis. The adoption, however, will result in a gross up in total assets and total liabilities on the Company’s consolidated balance sheets. Please see Note 9 for more information on the Company’s minimum lease payments as of June 30, 2017. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”). ASU 2016-09 includes provisions intended to simplify various aspects related to how share-based payments are accounted for and disclosed. ASU 2016-09 is effective for public business entities for annual reporting periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption will be permitted in any interim or annual period, as long as all elements of the new standard are adopted at the same time. The Company intends to adopt this new standard in its September 30, 2017, Form 10-Q. The Company is currently evaluating the potential impact of this standard but does not currently expect the adoption to have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 adds to U.S. GAAP an impairment model (known as the current expected credit loss model) that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses. ASU 2016-13 is effective for public business entities that are SEC filers for fiscal years beginning after December 15, 2019, including interim periods within those years. Earlier application is permitted only for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is currently evaluating the potential impact of this standard on its consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 may change how an entity classifies certain cash receipts and cash payments on its statement of cash flows to reduce existing diversity in practice. The guidance will generally be applied retrospectively and is effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those years. Early adoption is permitted, and the Company is in the process of determining whether the standard will be early adopted. The Company is currently evaluating the potential impact of this standard but does not currently expect the adoption to have a material impact on the consolidated statements of cash flows. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (“ASU 2016-18”). Under ASU 2016-18, restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 is effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The guidance will be applied retrospectively, and early adoption is permitted. The Company is in the process of determining whether the standard will be early adopted but does not currently expect the adoption to have a material impact on its consolidated financial statements.