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Label Element Value
Thompson MidCap Fund | Thompson MidCap Fund  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk/Return [Heading] oef_RiskReturnHeading Thompson MidCap Fund
Objective [Heading] oef_ObjectiveHeading Investment Objective
Objective, Primary [Text Block] oef_ObjectivePrimaryTextBlock

The Thompson MidCap Fund (the “MidCap Fund”) seeks a high level of long-term capital appreciation by investing in securities of medium-sized companies.
Expense Heading [Optional Text] oef_ExpenseHeading Fees and Expenses of the MidCap Fund
Expense Narrative [Text Block] oef_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy and hold shares of the MidCap Fund.
Shareholder Fees Caption [Optional Text] oef_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Optional Text] oef_OperatingExpensesCaption Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination oef_FeeWaiverOrReimbursementOverAssetsDateOfTermination Mar. 31, 2026
Expense Example [Heading] oef_ExpenseExampleHeading Example
Expense Example Narrative [Text Block] oef_ExpenseExampleNarrativeTextBlock

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

 

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Portfolio Turnover [Heading] oef_PortfolioTurnoverHeading Portfolio Turnover
Portfolio Turnover [Text Block] oef_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 27% of the average value of its portfolio.
Portfolio Turnover, Rate oef_PortfolioTurnoverRate 27.00%
Strategy [Heading] oef_StrategyHeading Investments, Risks, and Performance
Strategy Narrative [Text Block] oef_StrategyNarrativeTextBlock

Principal Investment Strategies of the Fund

 

The MidCap Fund normally invests at least 80% of its net assets plus any borrowing for investment purposes in a diversified portfolio of equity securities of medium-sized companies that at the time of purchase fall within the 12-month average of the capitalization ranges of stocks in the Russell Midcap Index, the Fund’s benchmark. Although market capitalizations are constantly changing, as of December 31, 2024, the Russell Midcap Index included companies with market capitalizations between $205 million and $152 billion. The Fund’s equity investments included within this 80% may include common stocks, American Depositary Receipts (ADRs), and real estate investment trusts (REITs).

 

We invest in equity securities that possess most of the following characteristics:

 

●Strong market positions

●High barriers to entry and other competitive or technological advantages

●High returns on equity and assets

●Good growth prospects

●Strong management

●Relatively low debt burdens

 

We also generally seek to identify investment opportunities in equity securities of companies that we believe have above-average potential for earnings and dividend growth.

 

To achieve a better risk-adjusted return on its equity investments, the MidCap Fund invests in a diversified portfolio of companies, including companies from a blend of industries and style classes. We believe that holding a diverse group of stocks will provide competitive returns under different market environments relative to more narrow investment styles. Our flexible approach to equity investing enables us to adapt to changing market trends and conditions and to invest wherever we believe opportunity exists.
Bar Chart and Performance Table [Heading] oef_BarChartAndPerformanceTableHeading Past Performance
Performance Narrative [Text Block] oef_PerformanceNarrativeTextBlock

The bar chart and table below provide some indication of the risks of investing in the MidCap Fund by showing how the Fund’s total returns before taxes have varied from year to year and how the Fund’s average annual total returns (both before and after taxes) for one, five and ten years compare to a broad measure of market performance. As with all mutual funds, the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Performance Information Illustrates Variability of Returns [Text] oef_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and table below provide some indication of the risks of investing in the MidCap Fund by showing how the Fund’s total returns before taxes have varied from year to year and how the Fund’s average annual total returns (both before and after taxes) for one, five and ten years compare to a broad measure of market performance.
Performance Past Does Not Indicate Future [Text] oef_PerformancePastDoesNotIndicateFuture As with all mutual funds, the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading] oef_BarChartHeading MidCap Fund Calendar Year Total Returns
Bar Chart Closing [Text Block] oef_BarChartClosingTextBlock

The Fund’s highest/lowest quarterly results during this period were:

 

  Highest: 29.88% (quarter ended 6/30/20)  
  Lowest: -37.76% (quarter ended 3/31/20)  
Highest Quarterly Return, Label [Optional Text] oef_HighestQuarterlyReturnLabel Highest
Highest Quarterly Return, Date oef_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return oef_BarChartHighestQuarterlyReturn 29.88%
Lowest Quarterly Return, Label [Optional Text] oef_LowestQuarterlyReturnLabel Lowest
Lowest Quarterly Return, Date oef_BarChartLowestQuarterlyReturnDate Mar. 31, 2020
Lowest Quarterly Return oef_BarChartLowestQuarterlyReturn (37.76%)
Performance Table Heading oef_PerformanceTableHeading MidCap Fund Average Annual Total Returns (for the periods ended December 31, 2024)
Index No Deduction for Fees, Expenses, or Taxes [Text] oef_IndexNoDeductionForFeesExpensesTaxes (reflects no deduction for fees, expenses, or taxes)
Performance Table Uses Highest Federal Rate oef_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the highest individual federal marginal income tax rate for 2024 and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred oef_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Closing [Text Block] oef_PerformanceTableClosingTextBlock

After-tax returns are calculated using the highest individual federal marginal income tax rate for 2024 and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

 

The S&P 500 Index is a product of S&P Dow Jones Indices LLC and has been licensed for use by Thompson Investment Management, Inc. S&P® and S&P 500® are registered trademarks of S&P. The Thompson IM Funds are not sponsored, endorsed, sold or promoted by S&P Dow Jones Indices LLC, Dow Jones, S&P or their respective affiliates, and none of S&P Dow Jones Indices LLC, Dow Jones, S&P nor their respective affiliates makes any representation regarding the advisability of investing in such products.

 

FTSE Russell is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. “FTSE®” and “Russell®” are trademarks of the London Stock Exchange Group.
Thompson MidCap Fund | Thompson MidCap Fund | Risk Lose Money [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock Like all investments, an investment in the MidCap Fund is subject to risks, and you could lose money investing in the Fund.
Thompson MidCap Fund | Thompson MidCap Fund | Market Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Market Risk. The value of equity securities in the Fund’s portfolio may decline, resulting in a decline in the Fund’s share price and total return. The equity securities held by the MidCap Fund fluctuate in value due to changes in the securities markets, general economic conditions and factors that particularly affect the issuers of these securities and their industries.
Thompson MidCap Fund | Thompson MidCap Fund | Mid Cap Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Mid Cap Risk. The medium-sized companies in which the MidCap Fund invests often have greater price volatility, lower trading volume and less liquidity than larger, more-established companies. As a class, medium-sized companies tend to have smaller revenues, narrower product lines, less management depth and experience, smaller shares of their product or services markets, fewer financial resources and less competitive strength than larger companies.
Thompson MidCap Fund | Thompson MidCap Fund | Active Management Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Active Management Risk. Our selection of securities for the MidCap Fund may not perform as well as expected when those securities were purchased or as well as the securities markets generally. The selection of securities for the MidCap Fund may be more or less heavily allocated to some sectors or types of securities than the Fund’s benchmark, which may cause the Fund’s performance and/or risk profile to differ significantly from its benchmark.
Thompson MidCap Fund | Thompson MidCap Fund | Style Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Style Risk. From time to time, we may prefer a certain investment style, such as a growth style or value style, that may underperform and/or be more volatile than other investment styles or than the stock markets generally during these periods.
Thompson MidCap Fund | Thompson MidCap Fund | Depositary Receipts Risk [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Depositary Receipts Risk. American Depositary Receipts (“ADRs”) are subject to some extent to the risks associated with directly investing in securities of foreign issuers, including the risk of changes in currency exchange rates, expropriation or nationalization of assets, and the impact of political, diplomatic, or social events. Additionally, some foreign issuers are subject to less stringent and less uniform regulatory, financial reporting, and accounting standards and practices than U.S. issuers.
Thompson MidCap Fund | Thompson MidCap Fund | Real Estate Investment Trusts [Member]  
Prospectus [Line Items] oef_ProspectusLineItems  
Risk [Text Block] oef_RiskTextBlock

Real Estate Investment Trusts. Real Estate Investment Trusts (“REITs”) are subject to the risks associated with owning real estate, depend on specialized management skills and may have limited diversification and smaller market capitalizations.
Thompson MidCap Fund | Thompson MidCap Fund | Thompson MidCap Fund  
Prospectus [Line Items] oef_ProspectusLineItems  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) oef_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) oef_MaximumDeferredSalesChargeOverOfferingPrice 0.00%
Maximum Sales Charge on Reinvested Dividends and Distributions (as a percentage) oef_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther 0.00%
Redemption Fee oef_RedemptionFee $ 0
Exchange Fee oef_ExchangeFee 0
Shareholder Fee, Other oef_ShareholderFeeOther $ 15
Management Fees (as a percentage of Assets) oef_ManagementFeesOverAssets 0.99%
Distribution and Service (12b-1) Fees oef_DistributionAndService12b1FeesOverAssets 0.00%
Other Expenses (as a percentage of Assets): oef_OtherExpensesOverAssets 0.39%
Expenses (as a percentage of Assets) oef_ExpensesOverAssets 1.38%
Fee Waiver or Reimbursement oef_FeeWaiverOrReimbursementOverAssets (0.23%) [1]
Net Expenses (as a percentage of Assets) oef_NetExpensesOverAssets 1.15%
Expense Example, with Redemption, 1 Year oef_ExpenseExampleYear01 $ 117
Expense Example, with Redemption, 3 Years oef_ExpenseExampleYear03 414
Expense Example, with Redemption, 5 Years oef_ExpenseExampleYear05 733
Expense Example, with Redemption, 10 Years oef_ExpenseExampleYear10 $ 1,637
Thompson MidCap Fund | Russell Midcap Index (reflects no deduction for fees, expenses, or taxes)  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Percent oef_AvgAnnlRtrPct 15.34%
Average Annual Return, Percent oef_AvgAnnlRtrPct 9.92%
Average Annual Return, Percent oef_AvgAnnlRtrPct 9.63%
Thompson MidCap Fund | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Percent oef_AvgAnnlRtrPct 25.02%
Average Annual Return, Percent oef_AvgAnnlRtrPct 14.53%
Average Annual Return, Percent oef_AvgAnnlRtrPct 13.10%
Thompson MidCap Fund | Thompson MidCap Fund  
Prospectus [Line Items] oef_ProspectusLineItems  
Annual Return [Percent] oef_AnnlRtrPct (9.49%)
Annual Return [Percent] oef_AnnlRtrPct 19.38%
Annual Return [Percent] oef_AnnlRtrPct 17.07%
Annual Return [Percent] oef_AnnlRtrPct (21.78%)
Annual Return [Percent] oef_AnnlRtrPct 33.45%
Annual Return [Percent] oef_AnnlRtrPct 11.97%
Annual Return [Percent] oef_AnnlRtrPct 29.61%
Annual Return [Percent] oef_AnnlRtrPct (14.74%)
Annual Return [Percent] oef_AnnlRtrPct 16.84%
Annual Return [Percent] oef_AnnlRtrPct 7.53%
Average Annual Return, Percent oef_AvgAnnlRtrPct 7.53%
Average Annual Return, Percent oef_AvgAnnlRtrPct 9.23%
Average Annual Return, Percent oef_AvgAnnlRtrPct 7.46%
Thompson MidCap Fund | Thompson MidCap Fund | After Taxes on Distributions  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.64%
Average Annual Return, Percent oef_AvgAnnlRtrPct 7.42%
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.80%
Thompson MidCap Fund | Thompson MidCap Fund | After Taxes on Distributions and Sales  
Prospectus [Line Items] oef_ProspectusLineItems  
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.82%
Average Annual Return, Percent oef_AvgAnnlRtrPct 7.15%
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.68%
[1] The Advisor has contractually agreed to waive management fees and/or reimburse expenses incurred by the MidCap Fund through March 31, 2026, so that the annual operating expenses of the Fund do not exceed 1.15% of its average daily net assets. This waiver/reimbursement may only be terminated by the Advisor with the consent of the Board of Directors of the Funds.