Strategy. The Fund is sub-advised by Weatherbie Capital, LLC (Weatherbie), an affiliate of the Manager (Weatherbie and the Manager, collectively referred to as the Manager, where applicable). Subject to the general supervision by the Funds Board of Trustees, the Manager oversees Weatherbie and evaluates its performance results. The Manager reviews portfolio performance, compliance with investment guidelines and federal securities laws, and changes in key personnel of Weatherbie. Weatherbie is primarily responsible for the day-to-day management of the Funds portfolio, including purchases and sales of individual securities. The Fund invests primarily in equity securities of mid-cap growth companies with an environmental, social and governance (ESG) rating of medium or better, as rated by Sustainalytics, a third-party ESG rating agency (Sustainalytics or the … Show more… The Fund is sub-advised by Weatherbie Capital, LLC (Weatherbie), an affiliate of the Manager (Weatherbie and the Manager, collectively referred to as the Manager, where applicable). Subject to the general supervision by the Funds Board of Trustees, the Manager oversees Weatherbie and evaluates its performance results. The Manager reviews portfolio performance, compliance with investment guidelines and federal securities laws, and changes in key personnel of Weatherbie. Weatherbie is primarily responsible for the day-to-day management of the Funds portfolio, including purchases and sales of individual securities. The Fund invests primarily in equity securities of mid-cap growth companies with an environmental, social and governance (ESG) rating of medium or better, as rated by Sustainalytics, a third-party ESG rating agency (Sustainalytics or the ESG Rating Agency), at the time of purchase. Sustainalytics provides ESG ratings that measure a companys exposure to ESG risks and how well the company is managing those risks. Using its proprietary methodology, as described below, Sustainalytics rates companies on a scale of 0 to 100, with 0 to 10 representing negligible ESG risk, 10 to 20 representing low ESG risk, 20 to 30 representing medium ESG risk, 30 to 40 representing high ESG risk, and 40 and higher representing severe ESG risk. Under normal circumstances, 80% of companies in the Funds portfolio, based on net assets, will have a Sustainalytics ESG rating. The Sustainalytics ESG ratings for this portion of the portfolio will have a weighted average of 25 or better. For determining the weighted average, the Sustainalytics ESG rating of a security comprising a higher percentage of the portfolio will have a greater impact than the Sustainalytics ESG rating of a security with a lower percentage of the portfolio on the weighted average ESG rating of this portion of the portfolio. As a result, the Fund may invest in companies with Sustainalytics ESG ratings above and below 25, although the Fund will not invest in a company if, as a result, the weighted average of the applicable portion of its portfolio would exceed a Sustainalytics ESG rating of 25. In addition, the Fund will not invest in a company with a Sustainalytics ESG rating of 40 or above (i.e., severe ESG risk) at the time of purchase. If an existing portfolio holdings ESG rating is adjusted by Sustainalytics to 40 or higher, Weatherbie will sell that portfolio holding within six months, subject to its fiduciary obligations to the Fund, although the Fund may continue to hold that investment if Sustainalytics readjusts the companys ESG rating back to below 40 as a result of positive actions taken by the company to reduce its ESG risk rating. Although the Fund expects to invest primarily in companies with ESG ratings provided by Sustainalytics, certain investments may not be rated by Sustainalytics. Reasons for this may be because (i) Sustainalytics does not include the company in its rating universe; and (ii) of timing differences between when the Fund may invest in a company and when, and if, that company receives an ESG rating from Sustainalytics. With respect to (ii) for example, Sustainalytics may take time to rate a particular company when it is newly publicly traded or as a result of a corporate action, such as a merger, spin-off or restructuring. The Fund may hold up to three securities totaling no more than 20% of the Funds net assets in securities, without a Sustainalytics ESG rating. If a company does receive an ESG rating from Sustainalytics, Weatherbie will include that company as part of the portion of the Funds portfolio that is required to maintain a weighted average ESG rating of 25 or better. In effecting the Funds investment strategy, Weatherbie initially employs fundamental analysis to identify innovative and dynamic companies that demonstrate promising growth potential such as strong earnings growth and sound stock market values. Weatherbie then uses Sustainalytics ESG ratings to determine whether an identified company is an appropriate investment for the Fund, including determining the impact that the investment would have on the Sustainalytics ESG rating of the Funds portfolio on a weighted average basis. In selecting and monitoring investments for the Fund, Weatherbie conducts due diligence on Sustainalytics, reviews the Sustainalytics ESG ratings of existing and potential portfolio investments, and separately engages with identified companies to determine whether a companys Sustainalytics ESG rating seems consistent with the companys practices. As part of Weatherbies fundamental analysis when considering investing in a company without a Sustainalytics ESG rating, Weatherbie will consider the companys ESG record in addition to the companys overall growth potential. With respect to its ESG ratings, Sustainalytics arrives at an ESG risk score for each company it rates by assessing the companys exposure to material ESG risks and assessing how well management manages the companys exposure to those risks. Regarding assessing exposure to material ESG risks, Sustainalytics uses a variety of criteria, which may change from time to time as part of its ratings process. The environmental criteria include, but are not limited to, climate change (carbon, energy efficiency, fines), natural resources (water stress, biodiversity), pollution and waste (air/water pollution, waste management), and environmental opportunities (clean technology, green building, renewable energy). The social criteria include, but are not limited to, human capital (labor management, development, supply chain, health and safety, employee sentiment, diversity), product liability (safety and quality, consumer satisfaction), stakeholder opposition (controversial sourcing), social opportunities (access to finance, healthcare, communications, nutrition and health, philanthropy), and board composition (diversity). The governance criteria include, but are not limited to, corporate governance (board, executive pay, ownership structure, accounting and disclosures, audit committee structure) and corporate behavior (business ethics, anti-competition strategies, corruption, lobbying, political contributions, shareholder rights). The overall Sustainalytics risk score for each company is a measure of whether or not, and how well, a company has responded to the various material ESG risks to which it is exposed. In evaluating a particular companys ESG rating, as well as the Funds weighted average ESG rating, the Fund relies exclusively on ratings provided by Sustainalytics. Sustainalytics periodically assesses companies for their exposure to and management of ESG risks and opportunities based on data collected from company filings, public disclosures and other sources. For purposes of the Funds principal investment strategies, mid-cap companies are those companies that, at the time of purchase of the securities, primarily have total market capitalization within the range of (i) companies included in the Russell Midcap Growth Index, as reported by the index at the most recent quarter end, or (ii) $1 billion to $25 billion. At December 31, 2022, the companies in this index ranged from $735.7 million to $ 52.8 billion. Because of the Funds long-term approach to investing, it could have a significant portion of its assets invested in securities of issuers that have appreciated beyond the market capitalization thresholds noted. The Fund intends to invest a substantial portion of its assets in a smaller number of issuers. Generally, the Fund will own no more than 30 holdings. As a result, the Fund is a non-diversified investment company, which means the performance results of any one position may have a greater impact on the Funds performance. Fund holdings may differ from this number for any reason. Such reasons may be, among others, because of extreme market volatility, such as when the Fund has entered a temporary defensive position. Additionally, the Fund may temporarily exceed the stated number of holdings when it acquires a new holding and determines that it is in the best interests of shareholders to sell an existing holding over a period of time, instead of immediately selling the entire holding. The Fund may invest a significant portion of its assets in securities of companies conducting business within a single sector. The Fund may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive. As a result, the Fund may engage in active trading of portfolio securities. The Fund can invest in foreign securities. The Fund invests in cash (and cash equivalents) when the Fund is unable to find enough attractive long-term investments to meet its investment objective, to meet redemptions and/or when the Manager believes it is advisable to do so during times of short-term market volatility. During these times, cash (and cash equivalents) will not exceed 15% of the Funds net assets. Show less