| N-2 - $ / shares | 12 Months Ended | ||||||
| Aug. 31, 2024 | Aug. 31, 2023 | Aug. 31, 2022 | Aug. 31, 2024 | Aug. 31, 2021 | Aug. 31, 2020 | Aug. 31, 2019 | |
| Prospectus [Line Items] | |||||||
| Document Period End Date | Aug. 31, 2024 | ||||||
| Cover [Abstract] | |||||||
| Entity Central Index Key | 0000810943 | ||||||
| Amendment Flag | false | ||||||
| Document Type | N-CSR | ||||||
| Entity Registrant Name | High Income Securities Fund | ||||||
| General Description of Registrant [Abstract] | |||||||
| Investment Objectives and Practices [Text Block] | Investment Objective, Investment Strategies, and Risk Factors The Fund’s investment objective is to seek to provide high current income as a primary objective and capital appreciation as a secondary objective. There can be no assurance that the Fund’s objectives will be achieved. The Board recently approved certain changes to the Fund’s current investment objective, investment strategies and fundamental and non-fundamental investment restrictions and recommended that the Shareholders approve such changes. Any such changes would be disclosed in a future registration statement. Investment Strategies The Investment Committee currently manages the Fund’s assets with a focus on discounted securities of income-oriented closed-end investment companies and business development companies. The Board may determine in the future that it is in the best interests of the Fund and its Shareholders to engage an investment advisory firm to manage the Fund’s assets. The Fund’s objective is pursued by primarily investing, under normal circumstances, at least 80% of its net assets in fixed income securities, including debt instruments, convertible securities and preferred stocks. The Fund also invests in high-yielding non-convertible securities with the potential for capital appreciation. The primary focus of the investment strategy is to acquire discounted securities of income-oriented closed-end investment companies and business development companies. In addition, units or common shares issued by special purpose acquisition companies (SPACs) may comprise up to 20% of the Fund’s portfolio at the time of purchase. The Fund may hold fixed income securities with any maturity or duration. The Fund may, from time to time, take temporary defensive positions that are inconsistent with the Fund’s principal investment strategies in attempting to respond to adverse market, economic, political or other conditions. During such times, the Fund may temporarily invest up to 100% of its assets in cash or cash equivalents, including money market instruments, prime commercial paper, repurchase agreements, Treasury bills and other short-term obligations of the U.S. Government, its agencies or instrumentalities. In these and in other cases, the Fund may not achieve its investment objective. The Investment Committee may invest the Fund’s cash balances in any investments it deems appropriate, subject to the “Fundamental Investment Restrictions” set forth in the Fund’s Statement of Additional Information and as permitted under the 1940 Act, including investments in repurchase agreements, money market funds, additional repurchase agreements, U.S. Treasury and U.S. agency securities, municipal bonds and bank accounts. Any income earned from such investments will ordinarily be reinvested by the Fund in accordance with its investment program. Many of the considerations entering into the Investment Committee’s recommendations and decisions are subjective. Portfolio Investments Other Closed-End Investment Companies The Fund may invest without limitation in other closed-end investment companies, provided that the Fund limits its investment in securities issued by other investment companies so that not more than 3% of the outstanding voting stock of any one investment company will be owned by the Fund. There can be no assurance that the investment objective of any investment company in which the Fund invests will be achieved. Closed-end investment companies are subject to the risks of investing in the underlying securities. The Fund, as a holder of the securities of the closed-end investment company, will bear its pro rata portion of the closed-end investment company’s expenses, including advisory fees. These expenses are in addition to the direct expenses of the Fund’s own operations. The closed end investment companies in which the Fund invests hold fixed income securities. The Fund “looks through” to these investments in determining whether at least 80% of the Fund’s investments are comprised of fixed income securities. Special Purpose Acquisition Companies The Fund may invest in stocks, warrants, and other securities of special purpose acquisition companies or similar special purpose entities that pool funds to seek potential acquisition opportunities (“SPACs”). Unless and until an acquisition meeting the SPAC’s requirements is completed, a SPAC generally invests its assets (less a portion retained to cover expenses) in U.S. Government securities, money market securities and cash. If an acquisition that meets the requirements for the SPAC is not completed within a pre-established period of time, the invested funds are returned to the entity’s shareholders. Because SPACs and similar entities have no operating history or ongoing business other than seeking acquisitions, the value of their securities is particularly dependent on the ability of the entity’s management to identify and complete a profitable acquisition. Some SPACs may pursue acquisitions only within certain industries or regions, which may increase the volatility of their prices. In addition, these securities, which are typically traded in the over-the-counter market, may be considered illiquid, be subject to restrictions on resale and/or may trade at a discount. Common Stocks The Fund will invest in common stocks. Common stocks represent an ownership interest in an issuer. While offering greater potential for long-term growth, common stocks are more volatile and riskier than some other forms of investment. Common stock prices fluctuate for many reasons, including adverse events, such as an unfavorable earnings report, changes in investors’ perceptions of the financial condition of an issuer or the general condition of the relevant stock market, or when political or economic events affecting the issuers occur. In addition, common stock prices may be sensitive to rising interest rates as the costs of capital rise and borrowing costs increase. Preferred Stocks The Fund may invest in preferred stocks. Preferred stock, like common stock, represents an equity ownership in an issuer. Generally, preferred stock has a priority of claim over common stock in dividend payments and upon liquidation of the issuer. Unlike common stock, preferred stock does not usually have voting rights. Preferred stock in some instances is convertible into common stock. Although they are equity securities, preferred stocks have characteristics of both debt and common stock. Like debt, their promised income is contractually fixed. Like common stock, they do not have rights to precipitate bankruptcy proceedings or collection activities in the event of missed payments. Other equity characteristics are their subordinated position in an issuer’s capital structure and that their quality and value are heavily dependent on the profitability of the issuer rather than on any legal claims to specific assets or cash flows. Distributions on preferred stock must be declared by the board of directors and may be subject to deferral, and thus they may not be automatically payable. Income payments on preferred stocks may be cumulative, causing dividends and distributions to accrue even if not declared by the company’s board or otherwise made payable, or they may be non-cumulative, so that skipped dividends and distributions do not continue to accrue. There is no assurance that dividends on preferred stocks in which the Fund invests will be declared or otherwise made payable. The Fund may invest in non-cumulative preferred stock, although the Investment Committee may consider, among other factors, their non-cumulative nature in making any decision to purchase or sell such securities. Shares of preferred stock have a liquidation value that generally equals the original purchase price at the date of issuance. The market values of preferred stock may be affected by favorable and unfavorable changes impacting the issuers’ industries or sectors, including companies in the utilities and financial services sectors, which are prominent issuers of preferred stock. They may also be affected by actual and anticipated changes or ambiguities in the tax status of the security and by actual and anticipated changes or ambiguities in tax laws, such as changes in corporate and individual income tax rates, and in the dividends received deduction for corporate taxpayers or the lower rates applicable to certain dividends. Because the claim on an issuer’s earnings represented by preferred stock may become onerous when interest rates fall below the rate payable on the stock or for other reasons, the issuer may redeem preferred stock, generally after an initial period of call protection in which the stock is not redeemable. Thus, in declining interest rate environments in particular, the Fund’s holdings of higher dividend-paying preferred stocks may be reduced and the Fund may be unable to acquire securities paying comparable rates with the redemption proceeds. Warrants The Fund may invest in equity and index warrants of domestic and international issuers. Equity warrants are securities that give the holder the right, but not the obligation, to subscribe for equity issues of the issuing company or a related company at a fixed price either on a certain date or during a set period. Changes in the value of a warrant do not necessarily correspond to changes in the value of its underlying security. The price of a warrant may be more volatile than the price of its underlying security, and a warrant may offer greater potential for capital appreciation as well as capital loss. Warrants do not entitle a holder to dividends or voting rights with respect to the underlying security and do not represent any rights in the assets of the issuing company. A warrant ceases to have value if it is not exercised prior to its expiration date. These factors can make warrants more speculative than other types of investments. The sale of a warrant results in a long or short-term capital gain or loss depending on the period for which the warrant is held. Corporate Bonds, Government Debt Securities and Other Debt Securities The Fund may invest in corporate bonds, debentures and other debt securities or in investment companies which hold such instruments. Bonds and other debt securities generally are issued by corporations and other issuers to borrow money from investors. The issuer pays the investor a fixed rate of interest and normally must repay the amount borrowed on or before maturity. Certain debt securities are “perpetual” in that they have no maturity date. The Fund will invest in government debt securities, including those of emerging market issuers or of other non-U.S. issuers. These securities may be U.S. dollar-denominated or non-U.S. dollar-denominated and include: (a) debt obligations issued or guaranteed by foreign national, provincial, state, municipal or other governments with taxing authority or by their agencies or instrumentalities; and (b) debt obligations of supranational entities. Government debt securities include: debt securities issued or guaranteed by governments, government agencies or instrumentalities and political subdivisions; debt securities issued by government owned, controlled or sponsored entities; interests in entities organized and operated for the purpose of restructuring the investment characteristics issued by the above noted issuers; or debt securities issued by supranational entities such as the World Bank or the European Union. The Fund may also invest in securities denominated in currencies of emerging market countries. Emerging market debt securities generally are rated in the lower rating categories of recognized credit rating agencies or are unrated and considered to be of comparable quality to lower rated debt securities. Convertible Securities The Fund may invest in convertible securities. Convertible securities include fixed income securities that may be exchanged or converted into a predetermined number of shares of the issuer’s underlying common stock at the option of the holder during a specified period. Convertible securities may take the form of convertible preferred stock, convertible bonds or debentures, units consisting of “usable” bonds and warrants or a combination of the features of several of these securities. The investment characteristics of each convertible security vary widely, which allows convertible securities to be employed for a variety of investment strategies. The Fund will exchange or convert convertible securities into shares of underlying common stock when, in the opinion of the Investment Committee, the investment characteristics of the underlying common shares will assist the Fund in achieving its investment objective. The Fund may also elect to hold or trade convertible securities. In selecting convertible securities, the Investment Committee evaluates the investment characteristics of the convertible security as a fixed income instrument, and the investment potential of the underlying equity security for capital appreciation. In evaluating these matters with respect to a particular convertible security, the Investment Committee considers numerous factors, including the economic and political outlook, the value of the security relative to other investment alternatives, trends in the determinants of the issuer’s profits, and the issuer’s management capability and practices. Other Securities Although it has no current intention to do so to any material extent, the Fund may determine to invest the Fund’s assets in some or all of the following securities. Illiquid Securities Illiquid securities are securities that are not readily marketable. Illiquid securities include securities that have legal or contractual restrictions on resale, and repurchase agreements maturing in more than seven days. Illiquid securities involve the risk that the securities will not be able to be sold at the time desired or at prices approximating the value at which the Fund is carrying the securities. Where registration is required to sell a security, the Fund may be obligated to pay all or part of the registration expenses, and a considerable period may elapse between the decision to sell and the time the Fund may be permitted to sell a security under an effective registration statement. If, during such a period, adverse market conditions were to develop, the Fund might obtain a less favorable price than prevailed when it decided to sell. The Fund may invest up to 10% of the value of its net assets in illiquid securities. Restricted securities for which no market exists and other illiquid investments are valued at fair value as determined in accordance with procedures approved and periodically reviewed by the Board of Trustees. The Fund does not consider its investments in SPACs to be illiquid because they are publicly traded securities. Rule 144A Securities The Fund may invest in restricted securities that are eligible for resale pursuant to Rule 144A under the Securities Act of 1933, as amended, (the “1933 Act”). Generally, Rule 144A establishes a safe harbor from the registration requirements of the 1933 Act for resale by large institutional investors of securities that are not publicly traded. The Investment Committee determines the liquidity of the Rule 144A securities according to guidelines adopted by the Board of Trustees. The Board of Trustees monitors the application of those guidelines and procedures. Securities eligible for resale pursuant to Rule 144A, which are determined to be liquid, are not subject to the Fund’s 10% limit on investments in illiquid securities. | ||||||
| Risk Factors [Table Text Block] | RISK FACTORS An investment in the Fund is not guaranteed to achieve its investment objective; is not a deposit with a bank; is not insured, endorsed or guaranteed by the Federal Deposit Insurance Corporation or any other government agency; and is subject to investment risks. The value of the Fund’s investments will increase or decrease based on changes in the prices of the investments it holds. You could lose money by investing in the Fund. By itself, the Fund does not constitute a balanced investment program. You should consider carefully the following principal and non-principal risks before investing in the Fund. There may be additional risks that the Fund does not currently foresee or consider material. You may wish to consult with your legal or tax advisors, before deciding whether to invest in the Fund. This section describes the risk factors associated with investment in the Fund specifically, as well as those factors generally associated with investment in an investment company with investment objectives, investment policies, capital structure or trading markets similar to the Fund’s. Each risk summarized below is a risk of investing in the Fund and different risks may be more significant at different times depending upon market conditions or other factors. The Fund may invest in securities of other investment companies (“underlying funds”). The Fund may be subject to the risks of the securities and other instruments described below through its own direct investments and indirectly through investments in the underlying funds. Principal Risks Closed-End Investment Company Risk. Special Purpose Acquisition Companies Risk. within certain industries or regions, which may increase the volatility of their prices. In addition, these securities, which are typically traded in the over-the-counter market, may be considered illiquid, be subject to restrictions on resale, and/or may trade at a discount. The Fund may invest a maximum of 20% of its assets in SPACS. Business Development Company (BDC) Risk. Management Risk. Market Risk. Local, state, regional, national or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, recessions, or other events could have a significant impact on the Fund and its investments and could result in decreases to the Fund’s net asset value. Political, geopolitical, natural and other events, including war, terrorism, trade disputes, government shutdowns, market closures, natural and environmental disasters, epidemics, pandemics and other public health crises and related events and governments’ reactions to such events have led, and in the future may lead, to economic uncertainty, decreased economic activity, increased market volatility and other disruptive effects on U.S. and global economies and markets. Such events may have significant adverse direct or indirect effects on the Fund and its investments. For example, a widespread health crisis such as a global pandemic could cause substantial market volatility, exchange trading suspensions and closures, impact the ability to complete redemptions, and affect Fund performance. A health crisis may exacerbate other pre-existing political, social and economic risks. In addition, the increasing interconnectedness of markets around the world may result in many markets being affected by events or conditions in a single country or region or events affecting a single or small number of issuers. COVID-19 resulted in travel restrictions, closed international borders, enhanced health screenings at ports of entry and elsewhere, disruption of and delays in healthcare service preparation and delivery, prolonged quarantines, cancellations, business and school closings, supply chain disruptions, and lower consumer demand, as well as general concern and uncertainty. The impact of COVID-19, and other infectious illness outbreaks that may arise in the future, could adversely affect the economies of many nations or the entire global economy, individual issuers and capital markets in ways that cannot necessarily be foreseen. In addition, the impact of infectious illnesses in emerging market countries may be greater due to generally less established healthcare systems. Risk Related to Fixed Income Securities, including Non-Investment Grade Securities. debt typically pays a higher yield, such investments involve substantial risk of loss. Junk bonds are considered predominantly speculative with respect to the issuer’s ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for junk bonds tend to be very volatile and those securities are less liquid than investment grade debt securities. Moreover, junk bonds pose a greater risk that exercise of any of their redemption or call provisions in a declining market may result in their replacement by lower-yielding bonds. In addition, bonds in the lowest two investment grade categories, despite being of higher credit rating than junk bonds, have speculative characteristics with respect to the issuer’s ability to pay interest and principal and their susceptibility to default or decline in market value. The Fund’s investments in securities of stressed, distressed or bankrupt issuers, including securities or obligations that are in default, generally trade significantly below par and are considered speculative. There is even a potential risk of loss by the Fund of its entire investment in such securities. There are a number of significant risks inherent in the bankruptcy process. A bankruptcy filing by an issuer may adversely and permanently affect the market position and operations of the issuer. If an issuer of securities held by the Fund declares bankruptcy or otherwise fails to pay principal or interest on such securities, the Fund would experience a decrease in income and a decline in the market value of its investments. Interest Rate Risk. Credit Risk. Extension Risk. Debt Security Risk. Market Discount from Net Asset Value Risk. Real Estate Investment Trust (REIT) Risk. Leverage Risk. Derivatives Risk. Defensive Position Risk. Changes in Policies Risk. Preferred Stock Risk. Investment in preferred stocks carries risks, including credit risk, deferral risk, redemption risk, limited voting rights, risk of subordination and lack of liquidity. Fully taxable or hybrid preferred securities typically contain provisions that allow an issuer, at its discretion, to defer distributions for up to 20 consecutive quarters. Distributions on preferred stock must be declared by the board of trustees and may be subject to deferral, and thus they may not be automatically payable. Income payments on preferred stocks may be cumulative, causing dividends and distributions to accrue even if not declared by the company’s board or otherwise made payable, or they may be non-cumulative, so that skipped dividends and distributions do not continue to accrue. There is no assurance that dividends on preferred stocks in which the Fund invests will be declared or otherwise made payable. The Fund may invest in non-cumulative preferred stock, although the Fund’s Investment Committee would consider, among other factors, their non-cumulative nature in making any decision to purchase or sell such securities. Shares of preferred stock have a liquidation value that generally equals the original purchase price at the date of issuance. The market values of preferred stock may be affected by favorable and unfavorable changes impacting the issuers’ industries or sectors, including companies in the utilities and financial services sectors, which are prominent issuers of preferred stock. They may also be affected by actual and anticipated changes or ambiguities in the tax status of the security and by actual and anticipated changes or ambiguities in tax laws, such as changes in corporate and individual income tax rates, and in the dividends received deduction for corporate taxpayers or the lower rates applicable to certain dividends. Because the claim on an issuer’s earnings represented by preferred stock may become onerous when interest rates fall below the rate payable on the stock or for other reasons, the issuer may redeem preferred stock, generally after an initial period of call protection in which the stock is not redeemable. Thus, in declining interest rate environments in particular, the Fund’s holdings of higher dividend paying preferred stocks may be reduced and the Fund may be unable to acquire securities paying comparable rates with the redemption proceeds. In the event of a redemption, the Fund may not be able to reinvest the proceeds at comparable rates of return. Convertible Securities Risk. security, the Fund’s Investment Committee considers numerous factors, including the economic and political outlook, the value of the security relative to other investment alternatives, trends in the determinants of the issuer’s profits, and the issuer’s management capability and practices. The value of a convertible security, including, for example, a warrant, is a function of its “investment value” (determined by its yield in comparison with the yields of other securities of comparable maturity and quality that do not have a conversion privilege) and its “conversion value” (the security’s worth, at market value, if converted into the underlying common stock). The investment value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors may also have an effect on the convertible security’s investment value. The conversion value of a convertible security is determined by the market price of the underlying common stock. If the conversion value is low relative to the investment value, the price of the convertible security is governed principally by its investment value. Generally, the conversion value decreases as the convertible security approaches maturity. To the extent the market price of the underlying common stock approaches or exceeds the conversion price, the price of the convertible security will be increasingly influenced by its conversion value. A convertible security generally will sell at a premium over its conversion value by the extent to which investors place value on the right to acquire the underlying common stock while holding a fixed income security. A convertible security may be subject to redemption at the option of the issuer at a price established in the convertible security’s governing instrument. If a convertible security held by the Fund is called for redemption, the Fund will be required to permit the issuer to redeem the security, convert it into the underlying common stock or sell it to a third party. Any of these actions could have an adverse effect on the Fund’s ability to achieve its investment objective. Issuer Specific Changes Risk. Non-Principal Risks In addition to the principal risks set forth above, the following additional risks may apply to an investment in the Fund. Anti-Takeover Provisions Risk. Common Stock Risk. Exchange Traded Funds Risk. Foreign Currency Risk. exchange. Certain currencies are more volatile than those of other countries and Fund investments related to those countries may be more affected. Generally, if a foreign currency depreciates against the dollar (i.e., if the dollar strengthens), the value of the existing investment in the securities denominated in that currency will decline. When a given currency appreciates against the dollar (i.e., if the dollar weakens), the value of the existing investment in securities denominated in that currency will rise. Certain foreign countries may impose restrictions on the ability of foreign securities issuers to make payments of principal and interest to investors located outside of the country, due to a blockage of foreign currency exchanges or otherwise. Foreign Securities Risk. Illiquid Securities Risk. Portfolio Turnover Risk. Small and Medium Cap Company Risk. | ||||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | |||||||
| Capital Stock [Table Text Block] | Note 5: Capital Share Transactions The Fund completed an offering to issue up to 100% of the Fund’s shares outstanding at 97% of the volume weighted average market price per share for the three consecutive trading days ending on the Expiration Date on August 9, 2024. At the expiration of the offer on August 9, 2024, a total of 11,860,987 rights or approximately 68% of the Fund’s outstanding common shares were validly exercised. The Fund completed an offering to issue up to 100% of the Fund’s shares outstanding at 95% of the volume weighted average market price per share for the three consecutive trading days ending on the trading day after the Expiration Date on October 22, 2021. At the expiration of the offer on October 22, 2021, a total of 8,042,590 rights or approximately 84.77% of the Fund’s outstanding common shares were validly exercised. The Fund completed an offering to issue up to 100% of the Fund’s shares outstanding at 95% of the volume weighted average market price per share for the three consecutive trading days ending on the trading day after the Expiration Date on January 29, 2021. At the expiration of the offer on January 29, 2021, a total of 3,922,867 rights or approximately 70.49% of the Fund’s outstanding common shares were validly exercised. Repurchases may be made when the Fund’s shares are trading at less than net asset value and in accordance with procedures approved by the Fund’s Previous Trustees. For the period September 1, 2023 through August 31, 2024 there were no common shares repurchased. | ||||||
| Closed-End Investment Company Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Closed-End Investment Company Risk. | ||||||
| Special Purpose Acquisition Companies Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Special Purpose Acquisition Companies Risk. within certain industries or regions, which may increase the volatility of their prices. In addition, these securities, which are typically traded in the over-the-counter market, may be considered illiquid, be subject to restrictions on resale, and/or may trade at a discount. The Fund may invest a maximum of 20% of its assets in SPACS. | ||||||
| Business Development Company (BDC) Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Business Development Company (BDC) Risk. | ||||||
| Management Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Management Risk. | ||||||
| Market Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Market Risk. Local, state, regional, national or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, recessions, or other events could have a significant impact on the Fund and its investments and could result in decreases to the Fund’s net asset value. Political, geopolitical, natural and other events, including war, terrorism, trade disputes, government shutdowns, market closures, natural and environmental disasters, epidemics, pandemics and other public health crises and related events and governments’ reactions to such events have led, and in the future may lead, to economic uncertainty, decreased economic activity, increased market volatility and other disruptive effects on U.S. and global economies and markets. Such events may have significant adverse direct or indirect effects on the Fund and its investments. For example, a widespread health crisis such as a global pandemic could cause substantial market volatility, exchange trading suspensions and closures, impact the ability to complete redemptions, and affect Fund performance. A health crisis may exacerbate other pre-existing political, social and economic risks. In addition, the increasing interconnectedness of markets around the world may result in many markets being affected by events or conditions in a single country or region or events affecting a single or small number of issuers. COVID-19 resulted in travel restrictions, closed international borders, enhanced health screenings at ports of entry and elsewhere, disruption of and delays in healthcare service preparation and delivery, prolonged quarantines, cancellations, business and school closings, supply chain disruptions, and lower consumer demand, as well as general concern and uncertainty. The impact of COVID-19, and other infectious illness outbreaks that may arise in the future, could adversely affect the economies of many nations or the entire global economy, individual issuers and capital markets in ways that cannot necessarily be foreseen. In addition, the impact of infectious illnesses in emerging market countries may be greater due to generally less established healthcare systems. | ||||||
| Risk Related to Fixed Income Securities, including Non-Investment Grade Securities [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Risk Related to Fixed Income Securities, including Non-Investment Grade Securities. debt typically pays a higher yield, such investments involve substantial risk of loss. Junk bonds are considered predominantly speculative with respect to the issuer’s ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for junk bonds tend to be very volatile and those securities are less liquid than investment grade debt securities. Moreover, junk bonds pose a greater risk that exercise of any of their redemption or call provisions in a declining market may result in their replacement by lower-yielding bonds. In addition, bonds in the lowest two investment grade categories, despite being of higher credit rating than junk bonds, have speculative characteristics with respect to the issuer’s ability to pay interest and principal and their susceptibility to default or decline in market value. The Fund’s investments in securities of stressed, distressed or bankrupt issuers, including securities or obligations that are in default, generally trade significantly below par and are considered speculative. There is even a potential risk of loss by the Fund of its entire investment in such securities. There are a number of significant risks inherent in the bankruptcy process. A bankruptcy filing by an issuer may adversely and permanently affect the market position and operations of the issuer. If an issuer of securities held by the Fund declares bankruptcy or otherwise fails to pay principal or interest on such securities, the Fund would experience a decrease in income and a decline in the market value of its investments. | ||||||
| Credit Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Credit Risk. | ||||||
| Extension Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Extension Risk. | ||||||
| Debt Security Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Debt Security Risk. | ||||||
| Market Discount from Net Asset Value Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Market Discount from Net Asset Value Risk. | ||||||
| Real Estate Investment Trust (REIT) Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Real Estate Investment Trust (REIT) Risk. | ||||||
| Leverage Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Leverage Risk. | ||||||
| Derivatives Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Derivatives Risk. | ||||||
| Defensive Position Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Defensive Position Risk. | ||||||
| Changes in Policies Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Changes in Policies Risk. | ||||||
| Preferred Stock Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Preferred Stock Risk. Investment in preferred stocks carries risks, including credit risk, deferral risk, redemption risk, limited voting rights, risk of subordination and lack of liquidity. Fully taxable or hybrid preferred securities typically contain provisions that allow an issuer, at its discretion, to defer distributions for up to 20 consecutive quarters. Distributions on preferred stock must be declared by the board of trustees and may be subject to deferral, and thus they may not be automatically payable. Income payments on preferred stocks may be cumulative, causing dividends and distributions to accrue even if not declared by the company’s board or otherwise made payable, or they may be non-cumulative, so that skipped dividends and distributions do not continue to accrue. There is no assurance that dividends on preferred stocks in which the Fund invests will be declared or otherwise made payable. The Fund may invest in non-cumulative preferred stock, although the Fund’s Investment Committee would consider, among other factors, their non-cumulative nature in making any decision to purchase or sell such securities. Shares of preferred stock have a liquidation value that generally equals the original purchase price at the date of issuance. The market values of preferred stock may be affected by favorable and unfavorable changes impacting the issuers’ industries or sectors, including companies in the utilities and financial services sectors, which are prominent issuers of preferred stock. They may also be affected by actual and anticipated changes or ambiguities in the tax status of the security and by actual and anticipated changes or ambiguities in tax laws, such as changes in corporate and individual income tax rates, and in the dividends received deduction for corporate taxpayers or the lower rates applicable to certain dividends. Because the claim on an issuer’s earnings represented by preferred stock may become onerous when interest rates fall below the rate payable on the stock or for other reasons, the issuer may redeem preferred stock, generally after an initial period of call protection in which the stock is not redeemable. Thus, in declining interest rate environments in particular, the Fund’s holdings of higher dividend paying preferred stocks may be reduced and the Fund may be unable to acquire securities paying comparable rates with the redemption proceeds. In the event of a redemption, the Fund may not be able to reinvest the proceeds at comparable rates of return. | ||||||
| Convertible Securities Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Convertible Securities Risk. security, the Fund’s Investment Committee considers numerous factors, including the economic and political outlook, the value of the security relative to other investment alternatives, trends in the determinants of the issuer’s profits, and the issuer’s management capability and practices. The value of a convertible security, including, for example, a warrant, is a function of its “investment value” (determined by its yield in comparison with the yields of other securities of comparable maturity and quality that do not have a conversion privilege) and its “conversion value” (the security’s worth, at market value, if converted into the underlying common stock). The investment value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors may also have an effect on the convertible security’s investment value. The conversion value of a convertible security is determined by the market price of the underlying common stock. If the conversion value is low relative to the investment value, the price of the convertible security is governed principally by its investment value. Generally, the conversion value decreases as the convertible security approaches maturity. To the extent the market price of the underlying common stock approaches or exceeds the conversion price, the price of the convertible security will be increasingly influenced by its conversion value. A convertible security generally will sell at a premium over its conversion value by the extent to which investors place value on the right to acquire the underlying common stock while holding a fixed income security. A convertible security may be subject to redemption at the option of the issuer at a price established in the convertible security’s governing instrument. If a convertible security held by the Fund is called for redemption, the Fund will be required to permit the issuer to redeem the security, convert it into the underlying common stock or sell it to a third party. Any of these actions could have an adverse effect on the Fund’s ability to achieve its investment objective. | ||||||
| Issuer Specific Changes Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Issuer Specific Changes Risk. | ||||||
| Anti-Takeover Provisions Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Anti-Takeover Provisions Risk. | ||||||
| Common Stock Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Common Stock Risk. | ||||||
| Exchange Traded Funds Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Exchange Traded Funds Risk. | ||||||
| Foreign Currency Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Foreign Currency Risk. exchange. Certain currencies are more volatile than those of other countries and Fund investments related to those countries may be more affected. Generally, if a foreign currency depreciates against the dollar (i.e., if the dollar strengthens), the value of the existing investment in the securities denominated in that currency will decline. When a given currency appreciates against the dollar (i.e., if the dollar weakens), the value of the existing investment in securities denominated in that currency will rise. Certain foreign countries may impose restrictions on the ability of foreign securities issuers to make payments of principal and interest to investors located outside of the country, due to a blockage of foreign currency exchanges or otherwise. | ||||||
| Foreign Securities Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Foreign Securities Risk. | ||||||
| Illiquid Securities Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Illiquid Securities Risk. | ||||||
| Portfolio Turnover Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Portfolio Turnover Risk. | ||||||
| Small and Medium Cap Company Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Small and Medium Cap Company Risk. | ||||||
| Interest Rate Risk [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Risk [Text Block] | Interest Rate Risk. | ||||||
| Common Shares [Member] | |||||||
| General Description of Registrant [Abstract] | |||||||
| Share Price | $ 6.67 | $ 6.76 | $ 7.15 | $ 6.67 | $ 9.92 | $ 8.10 | |
| NAV Per Share | $ 7.20 | $ 7.43 | $ 7.87 | $ 7.20 | $ 9.31 | $ 8.65 | $ 9.49 |
| Latest Premium (Discount) to NAV [Percent] | (7.36%) | ||||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | |||||||
| Outstanding Security, Not Held [Shares] | 29,391,450 | 17,530,463 | 17,530,463 |
