Real Estate Securities Trust Investment Risks - Real Estate Securities Trust	Dec. 31, 2025
Changing Distribution Levels Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Changing distribution levels risk.  The fund may cease or reduce the level of its distribution if income or dividends paid from its investments declines.
Concentration Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Concentration risk.  Because the fund may focus on one or more industries or sectors of the economy, its performance depends in large part on the performance of those industries or sectors. As a result, the value of an investment may fluctuate more widely since it is more susceptible to market, economic, political, regulatory, and other conditions and risks affecting those industries or sectors than a fund that invests more broadly across industries and sectors. A downturn in the real estate industry may significantly detract from performance.
Credit And Counterparty Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Credit and counterparty risk.  The issuer or guarantor of a fixed-income security, the counterparty to an over-the-counter derivatives contract, or a borrower of fund securities may not make timely payments or otherwise honor its obligations. A downgrade or default affecting any of the fund’s securities could affect the fund’s performance.
Economic And Market Events Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Economic and market events risk.  Events in the U.S. and global financial markets, including actions taken by the U.S. Federal Reserve or foreign central banks to stimulate or stabilize economic growth, may at times result in unusually high market volatility, which could negatively impact performance. Reduced liquidity in credit and fixed-income markets could adversely affect issuers worldwide. Banks and financial services companies could suffer losses if interest rates rise or economic conditions deteriorate.
Equity Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Equity securities risk.  The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions.
Fixed Income Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Fixed-income securities risk.  A rise in interest rates typically causes bond prices to fall. The longer the average maturity or duration of the bonds held by a fund, the more sensitive it will likely be to interest-rate fluctuations. An issuer may not make all interest payments or repay all or any of the principal borrowed. Changes in a security’s credit quality may adversely affect fund performance.
Foreign Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Foreign securities risk.  Less information may be publicly available regarding foreign issuers, including foreign government issuers. Foreign securities may be subject to foreign taxes and may be more volatile than U.S. securities. Currency fluctuations and political and economic developments may adversely impact the value of foreign securities.
Hedging Derivatives And Other Strategic Transactions Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Hedging, derivatives, and other strategic transactions risk.  Hedging, derivatives, and other strategic transactions may increase a fund’s volatility and could produce disproportionate losses, potentially more than the fund’s principal investment. Risks of these transactions are different from and possibly greater than risks of investing directly in securities and other traditional instruments. Under certain market conditions, derivatives could become harder to value or sell and may become subject to liquidity risk (i.e., the inability to enter into closing transactions). Derivatives and other strategic transactions that the fund intends to utilize include: futures contracts. Futures contracts generally are subject to counterparty risk.
High Portfolio Turnover Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	High portfolio turnover risk.  Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.
Large Company Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Large company risk.  Larger companies may grow more slowly than smaller companies or be slower to respond to business developments. Large-capitalization securities may underperform the market as a whole.
Liquidity Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Liquidity risk.  The extent (if at all) to which a security may be sold or a derivative position closed without negatively impacting its market value may be impaired by reduced market activity or participation, legal restrictions, or other economic and market impediments. Liquidity risk may be magnified in rising interest rate environments due to higher than normal redemption rates. Widespread selling of fixed-income securities to satisfy redemptions during periods of reduced demand may adversely impact the price or salability of such securities. Periods of heavy redemption could cause the fund to sell assets at a loss or depressed value, which could negatively affect performance. Redemption risk is heightened during periods of declining or illiquid markets.
Operational And Cybersecurity Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Operational and cybersecurity risk.  Cybersecurity breaches may allow an unauthorized party to gain access to fund assets, customer data, or proprietary information, or cause a fund or its service providers to suffer data corruption or lose operational functionality. Similar incidents affecting issuers of a fund’s securities may negatively impact performance. Operational risk may arise from human error, error by third parties, communication errors, or technology failures, among other causes.
Preferred And Convertible Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Preferred and convertible securities risk.  Preferred stock dividends are payable only if declared by the issuer’s board. Preferred stock may be subject to redemption provisions. The market values of convertible securities tend to fall as interest rates rise and rise as interest rates fall. Convertible preferred stock’s value can depend heavily upon the underlying common stock’s value.
Real Estate Investment Trust Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Real estate investment trust (REIT) risk.  REITs, pooled investment vehicles that typically invest in real estate directly or in loans collateralized by real estate, carry risks associated with owning real estate, including the potential for a decline in value due to economic or market conditions.
Real Estate Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Real estate securities risk.  Securities of companies in the real estate industry carry risks associated with owning real estate, including the potential for a decline in value due to economic or market conditions.
Small And Mid Sized Company Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Small and mid-sized company risk.  Small and mid-sized companies are generally less established and may be more volatile than larger companies. Small and/or mid-capitalization securities may underperform the market as a whole.
Risk Lose Money [Member]
Prospectus [Line Items]
Risk [Text Block]	Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.
Risk Not Insured Depository Institution [Member]
Prospectus [Line Items]
Risk [Text Block]	An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Risk Nondiversified Status [Member]
Prospectus [Line Items]
Risk [Text Block]	Non-diversified risk.  Adverse events affecting a particular issuer or group of issuers may magnify losses for non-diversified funds, which may invest a large portion of assets in any one issuer or a small number of issuers.