v3.25.4
Fees and Expenses
Mar. 02, 2026
Hennessy Cornerstone Growth Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.74%   0.74%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.43%   0.26%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.33%   0.26%  
Total Annual Fund Operating Expenses   1.32%   1.00%
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $134 $418 $723 $1,590
Institutional $102 $318 $552 $1,225
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 99% of the average value of its portfolio.
Portfolio Turnover, Rate 99.00%
Hennessy Focus Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.90%   0.90%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.43%   0.20%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.33%   0.20%  
Total Annual Fund Operating Expenses   1.48%   1.10%
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $151 $468 $808 $1,768
Institutional $112 $350 $606 $1,340
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 1% of the average value of its portfolio.
Portfolio Turnover, Rate 1.00%
Hennessy Cornerstone Mid Cap 30 Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES  (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES     Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.74%   0.74%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.45%   0.24%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.35%   0.24%  
Total Annual Fund Operating Expenses   1.34%   0.98%
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $136 $425 $734 $1,613
Institutional $100 $312 $542 $1,201
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 129% of the average value of its portfolio.
Portfolio Turnover, Rate 129.00%
Hennessy Cornerstone Large Growth Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.74%   0.74%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.40%   0.26%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.30%   0.26%  
Total Annual Fund Operating Expenses   1.29%   1.00%
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $131 $409 $708 $1,556
Institutional $102 $318 $552 $1,225
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 46% of the average value of its portfolio.
Portfolio Turnover, Rate 46.00%
Hennessy Cornerstone Value Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.74%   0.74%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.32%   0.25%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.22%   0.25%  
Total Annual Fund Operating Expenses   1.21%   0.99%
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $123 $384 $665 $1,466
Institutional $101 $315 $547 $1,213
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 27.00%
Hennessy Total Return Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES     
(fees paid directly from your investment)   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES     
(expenses that you pay each year as a percentage of the value of your investment)    
Management Fees   0.60%
Distribution and Service (12b-1) Fees   0.15%
Other Expenses   2.50%
Shareholder Servicing 0.10%  
Interest Expense 1.98%  
Remaining Other Expenses 0.42%  
Total Annual Fund Operating Expenses   3.25%
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 the assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years  
  $328 $1,001 $1,698 $3,549  
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 35% of the average value of its portfolio.
Portfolio Turnover, Rate 35.00%
Hennessy Equity and Income Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] Shareholder Fees (fees paid directly from your investment)
Shareholder Fees [Table]
Shareholder Fees    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your
Annual Fund Operating Expenses [Table]
Annual Fund Operating Expenses         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.80%   0.80%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.68%   0.46%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.58%   0.46%  
Total Annual Fund Operating Expenses   1.63%   1.26%
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $166 $514 $887 $1,933
Institutional $128 $400 $692 $1,523
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 27.00%
Hennessy Balanced Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES     
(fees paid directly from your investment)   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES     
(expenses that you pay each year as a percentage of the value of your investment)    
Management Fees   0.60%
Distribution and Service (12b-1) Fees   0.15%
Other Expenses   1.13%
Shareholder Servicing 0.10%  
Remaining Other Expenses 1.03%  
Total Annual Fund Operating Expenses   1.88%
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years  
  $191 $591 $1,016 $2,201  
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 39% of the average value of its portfolio.
Portfolio Turnover, Rate 39.00%
Hennessy Energy Transition Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   1.25%   1.25%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   1.30%   1.12%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 1.20%   1.12%  
Total Annual Fund Operating Expenses   2.70%   2.37%
Service Provider Expense Waiver1   (0.17)%   (0.17)%
Net Annual Fund Operating Expenses   2.53%   2.20%

 

1Certain service provider expenses will be voluntarily waived through July 31, 2028, at which time the arrangement will automatically terminate. In addition, the arrangement will not apply at any time the Fund’s net assets exceed $125 million.
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $256 $805 $1,399 $3,006
Institutional $223 $706 $1,234 $2,679
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 33% of the average value of its portfolio.
Portfolio Turnover, Rate 33.00%
Hennessy Midstream Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] Acquired fund fees and expenses are not reflected in the Fund’s financial statements, so the information presented in the expense table may differ from that presented in the financial highlights.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES  (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES  (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   1.10%   1.10%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.67%   0.43%
Shareholder Servicing 0.10%   None  
Franchise and Income        
  Tax Expenses1  0.00%   0.00%  
Remaining Other Expenses2  0.57%   0.43%  
Total Annual Fund Operating Expenses   1.92%   1.53%
Expense Reimbursement3,4    (0.16)%   (0.08)%
Total Annual Fund Operating Expenses        
  After Expense Reimbursement   1.76%   1.45%

 

1 Includes state franchise taxes and federal and state income tax expenses, including deferred tax expenses (benefits). The Fund accrues a deferred tax liability (or asset) for its future tax liability associated with the Fund’s potential tax expense (benefit) if it were to recognize the unrealized gains (losses) in its portfolio. Such deferred tax expenses (benefits) may vary greatly from year to year and from day to day depending on the nature of the Fund’s investments, the performance of those investments, and general market conditions, and any estimate of deferred income tax expense (benefit) cannot be reliably predicted from year to year.
2 Includes acquired fund fees and expenses that do not exceed 0.01% of the Fund’s average daily net assets. Acquired fund fees and expenses are not reflected in the Fund’s financial statements, so the information presented in the expense table may differ from that presented in the financial highlights.
3 The Fund’s investment manager has contractually agreed to ensure that total operating expenses (exclusive of all federal, state, and local taxes, interest, brokerage commissions, dividend and interest expenses on short sales, acquired fund fees and expenses and other costs incurred in connection with the purchase and sale of securities, and extraordinary items) do not exceed 1.75% and 1.50% of the average daily net assets of the Investor Class and Institutional Class shares of the Fund, respectively. The contractual arrangement will continue until February 28, 2027, at which time the contractual arrangement will automatically terminate (and it may not be terminated prior to that date). The Fund’s investment manager may recoup reimbursed amounts for three years after the reimbursement occurred if total expenses, including such recoupment, do not exceed the annual expense limit in effect at the time of such reimbursement or such recoupment.
4 Certain service provider expenses will be voluntarily waived through July 31, 2028, at which time the arrangement will automatically terminate. In addition, the arrangement will not apply at any time the Fund’s net assets exceed $125 million.
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of this 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $179 $577 $1,012 $2,222
Institutional $148 $467 $   819 $1,810
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 6% of the average value of its portfolio.
Portfolio Turnover, Rate 6.00%
Hennessy Gas Utility Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] Shareholder Fees  (fees paid directly from your investment)
Shareholder Fees [Table]
Shareholder Fees    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] Annual Fund Operating Expenses  (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
Annual Fund Operating Expenses         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.40%   0.40%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.42%   0.27%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.32%   0.27%  
Total Annual Fund Operating Expenses   0.97%   0.67%
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $99 $309 $536 $1,190
Institutional $68 $214 $373 $   835
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 26% of the average value of its portfolio.
Portfolio Turnover, Rate 26.00%
Hennessy Japan Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] Acquired fund fees and expenses are not reflected in the Fund’s financial statements, so the information presented in the expense table may differ from that presented in the financial highlights.
Shareholder Fees Caption [Optional Text] Shareholder Fees  (fees paid directly from your investment)
Shareholder Fees [Table]
Shareholder Fees    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] Annual Fund Operating Expenses  (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
Annual Fund Operating Expenses         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.80%   0.80%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.46%   0.25%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses1  0.36%   0.25%  
Total Annual Fund Operating Expenses   1.41%   1.05%

 

1 Includes acquired fund fees and expenses that do not exceed 0.01% of the Fund’s average daily net assets. Acquired fund fees and expenses are not reflected in the Fund’s financial statements, so the information presented in the expense table may differ from that presented in the financial highlights.
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $144 $446 $771 $1,691
Institutional $107 $334 $579 $1,283
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 16% of the average value of its portfolio.
Portfolio Turnover, Rate 16.00%
Hennessy Japan Small Cap Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] Acquired fund fees and expenses are not reflected in the Fund’s financial statements, so the information presented in the expense table may differ from that presented in the financial highlights.
Shareholder Fees Caption [Optional Text] Shareholder Fees  (fees paid directly from your investment)
Shareholder Fees [Table]
Shareholder Fees    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] Annual Fund Operating Expenses  (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
Annual Fund Operating Expenses         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.80%   0.80%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.55%   0.31%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses1  0.45%   0.31%  
Total Annual Fund Operating Expenses   1.50%   1.11%

 

1 Includes acquired fund fees and expenses that do not exceed 0.01% of the Fund’s average daily net assets. Acquired fund fees and expenses are not reflected in the Fund’s financial statements, so the information presented in the expense table may differ from that presented in the financial highlights.
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $153 $474 $818 $1,791
Institutional $113 $353 $612 $1,352
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 45% of the average value of its portfolio.
Portfolio Turnover, Rate 45.00%
Hennessy Large Cap Financial Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] Shareholder Fees (fees paid directly from your investment)
Shareholder Fees [Table]
Shareholder Fees    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
Annual Fund Operating Expenses         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.90%   0.90%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.83%   0.65%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.73%   0.65%  
Total Annual Fund Operating Expenses   1.88%   1.55%
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $191 $591 $1,016 $2,201
Institutional $158 $490 $   845 $1,845
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 48% of the average value of its portfolio.
Portfolio Turnover, Rate 48.00%
Hennessy Small Cap Financial Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] Shareholder Fees (fees paid directly from your investment)
Shareholder Fees [Table]
Shareholder Fees    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
Annual Fund Operating Expenses         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.90%   0.90%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   0.60%   0.43%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 0.50%   0.43%  
Total Annual Fund Operating Expenses   1.65%   1.33%
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of 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 you reinvest all dividends and distributions, 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 those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $168 $520 $897 $1,955
Institutional $135 $421 $729 $1,601
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 35% of the average value of its portfolio.
Portfolio Turnover, Rate 35.00%
Hennessy Technology Fund  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text] Shareholder Fees (fees paid directly from your investment)
Shareholder Fees [Table]
Shareholder Fees    Investor   Institutional
(fees paid directly from your investment)   None   None
Operating Expenses Caption [Optional Text] Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
Annual Fund Operating Expenses         
(expenses that you pay each year as a percentage of the value of your investment)        
Management Fees   0.74%   0.74%
Distribution and Service (12b-1) Fees   0.15%   None
Other Expenses   1.99%   1.86%
Shareholder Servicing 0.10%   None  
Remaining Other Expenses 1.89%   1.86%  
Total Annual Fund Operating Expenses   2.88%   2.60%
Expense Reimbursement1,2   (1.64)%   (1.61)%
Total Annual Fund Operating Expenses        
  After Expense Reimbursement   1.24%   0.99%

 

1The Fund’s investment manager has contractually agreed to ensure that total operating expenses (exclusive of all federal, state and local taxes, interest, brokerage commissions, 12b-1 fees, shareholder servicing fees payable to the Fund’s investment manager, acquired fund fees and expenses and other costs incurred in connection with the purchase and sale of securities, and extraordinary items) do not exceed 0.98% of the average daily net assets of Investor Class and Institutional Class shares of the Fund. The contractual arrangement will continue until February 28, 2027, at which time the contractual arrangement will automatically terminate (and it may not be terminated prior to that date). The Fund’s investment manager may recoup reimbursed amounts for three years after the reimbursement occurred if total expenses, including such recoupment, do not exceed the annual expense limit in effect at the time of such reimbursement or such recoupment.

2Certain service provider expenses will be voluntarily waived through July 31, 2028, at which time the arrangement will automatically terminate. In addition, the arrangement will not apply at any time the Fund’s net assets exceed $125 million.
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of 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 you reinvest all dividends and distributions, that your investment has a 5% return each year, and that the Fund’s operating expenses are equal to the total annual fund operating expenses after expense reimbursement for the first year and equal to total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, based on those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years
Investor $126 $713 $1,351 $3,068
Institutional $101 $631 $1,213 $2,795
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 99% of the average value of its portfolio.
Portfolio Turnover, Rate 99.00%
Hennessy Sustainable ETF  
Prospectus [Line Items]  
Expense Heading [Optional Text] Fund Fees and Expenses
Expense Narrative [Text Block]

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below.
Shareholder Fees Caption [Optional Text] SHAREHOLDER FEES (fees paid directly from your investment)
Shareholder Fees [Table]
SHAREHOLDER FEES   
(fees paid directly from your investment) None
Operating Expenses Caption [Optional Text] ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Annual Fund Operating Expenses [Table]
ANNUAL FUND OPERATING EXPENSES   
(expenses that you pay each year as a percentage of the value of your investment)  
Management Fees 0.95%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses 0.00%
Total Annual Fund Operating Expenses 0.95%
Expense Reimbursement1 (0.10)%
Total Annual Fund Operating Expenses  
  After Expense Reimbursement 0.85%

 

1 The Fund’s investment manager has contractually agreed to ensure that total operating expenses (excluding brokerage commissions, taxes, interest expense, acquired fund fees and expenses, and any extraordinary expenses) do not exceed 0.85% of the Fund’s average daily net assets. The contractual arrangement will continue until February 28, 2027, at which time it will automatically terminate (and it may not be terminated prior to that date). The Fund’s investment manager may recoup reimbursed amounts for three years after the reimbursement occurred if total expenses, including such recoupment, do not exceed the annual expense limit in effect at the time of such reimbursement or such recoupment.
Expense Example [Heading] EXAMPLE
Expense Example Narrative [Text Block]

This Example is intended to help you compare the cost of investing in shares of the Fund with the cost of investing in other 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 you reinvest all dividends and distributions, that your investment has a 5% return each year, and that the Fund’s operating expenses are equal to the total annual fund operating expenses after expense reimbursement for the first year and equal to total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, based on those assumptions, your costs would be:
Expense Example, With Redemption [Table]
  One Year Three Years Five Years Ten Years  
  $87 $293 $516 $1,157  
Portfolio Turnover [Heading] Portfolio Turnover
Portfolio Turnover [Text Block]

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 Total 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 275% of the average value of its portfolio.
Portfolio Turnover, Rate 275.00%