Health Sciences Trust Investment Strategy - Health Sciences Trust	Dec. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block]	Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in common stocks of companies engaged, at the time of investment, in the research, development, production, or distribution of products or services related to health care, medicine, or the life sciences (collectively, “health sciences”). (The fund will provide written notice to shareholders at least 60 days prior to a change in its 80% investment policy.) While the fund may invest in companies of any size, the majority of its assets are expected to be invested in large- and mid-cap companies. The subadvisor’s portfolio managers divide the health sciences sector into four main areas: pharmaceutical companies, health care services companies, medical products and devices providers, and biotechnology firms. Their allocation among these four areas will vary depending on the relative potential within each area and the outlook for the overall health sciences sector. While most assets will be invested in U.S. common stocks, the fund may purchase other securities, including foreign securities, in keeping with its investment objective. The fund concentrates its investments (invests more than 25% of its total assets) in securities of companies in the health sciences sector, a comparatively narrow segment of the economy, and therefore may experience greater volatility than funds investing in a broader range of industries. In managing the fund, the subadvisor uses a fundamental, bottom-up analysis that seeks to identify high quality companies and the most compelling investment opportunities. In general, the fund will follow a growth investment strategy, seeking companies whose earnings are expected to grow faster than inflation and the economy in general. When stock valuations seem unusually high, however, a “value” approach, which gives preference to seemingly undervalued companies, may also be emphasized. The fund may invest up to 35% of its total assets in foreign securities (including emerging market securities) and may have exposure to foreign currencies through its investment in these securities, its direct holdings of foreign currencies or through its use of foreign currency exchange contracts for the purchase or sale of a fixed quantity of a foreign currency at a future date. In pursuing its investment objective, the fund’s management has the discretion to purchase some securities that do not meet its normal investment criteria, as described above, when it perceives an opportunity for substantial appreciation. These  situations might arise when the fund’s management believes a security could increase in value for a variety of reasons including a change in management, an extraordinary corporate event, or a new product introduction or innovation or a favorable competitive development. The fund may sell securities for a variety of reasons including to realize gains, limit losses or redeploy assets into more promising opportunities. Use of Hedging and Other Strategic Transactions. The fund is authorized to use all of the various investment strategies referred to under “Additional Information About the Funds’ Principal Risks — Hedging, derivatives and other strategic transactions risk” including entering into option transactions.
Strategy Portfolio Concentration [Text]	<span style="font-family:Arial Narrow;font-size:9pt;">Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in common stocks of companies engaged, at the time of investment, in the research, development, production, or distribution of products or services related to health care, medicine, or the life sciences (collectively, “health sciences”).</span>