The Gabelli Utility Trust (GUT) N-CSR8 Mar 24Certified annual shareholder report (management investment company)Financial data

Company Profile

N-2

N-2 - USD ($)	3 Months Ended								12 Months Ended
N-2 - USD ($)	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cover [Abstract]
Entity Central Index Key									0001080720
Amendment Flag									false
Document Type									N-CSR
Entity Registrant Name									The Gabelli Utility Trust
Other Transaction Expenses [Abstract]
Annual Expenses [Table Text Block]									Annual Expenses Percentages of Net Assets Management Fees (a) 1.32 Interest on Borrowed Funds (b) 0.49 Other Expense (c) 0.58 Total Annual Expenses 2.39 Dividends on Preferred Shares (d) 1.20 Total Annual Expenses and Dividends on Preferred 3.59
Management Fees [Percent]									1.32%
Interest Expenses on Borrowings [Percent]									0.49%
Other Annual Expenses [Abstract]
Other Annual Expense 3 [Percent]									0.58%
Total Annual Expenses [Percent]									2.39%
Waivers and Reimbursements of Fees [Percent]									1.20%
Net Expense over Assets [Percent]									3.59%
Expense Example [Table Text Block]									The following example illustrates the expenses you would pay on a $1,000 investment in common Shares, assuming a 5% annual portfolio total return.* 1 Year 3 Year 5 Year 10 Year Total Expenses Incurred $36 $110 $186 $385 * The example should not be considered a representation of future expenses. The example is based on Total Annual Expenses and Dividends on Preferred Shares shown in the table above and assumes that the amounts set forth in the table do not change and that all distributions are reinvested at net asset value. Actual expenses may be greater or less than those assumed. Moreover, the Fund’s actual rate of return may be greater or less than the hypothetical 5% return shown in the example. The above example includes Dividends on Preferred Shares and Interest on Borrowed Funds. If Dividends on Preferred Shares and Interest on Borrowed Funds were not included in the example calculation, the expenses would be as follows (based on the same assumptions as above). 1 Year 3 Year 5 Year 10 Year Total Expenses Incurred $ 19 $ 60 $ 103 $ 222
Expense Example, Year 01									$ 36
Expense Example, Years 1 to 3									110
Expense Example, Years 1 to 5									186
Expense Example, Years 1 to 10									$ 385
Purpose of Fee Table , Note [Text Block]									The following table shows the Fund’s expenses, which are borne directly or indirectly by holders of the Fund’s common shares, including preferred shares and notes offering expenses, as a percentage of net assets attributable to common shares. All expenses of the Fund will be borne, directly or indirectly, by the common shareholders. Amounts are for the current fiscal year.
Other Expenses, Note [Text Block]									“Other Expenses” are based on the amounts for the year ended December 31, 2023.
General Description of Registrant [Abstract]
Investment Objectives and Practices [Text Block]									Investment Objective and Strategies During the Fund’s most recent fiscal year, there were no material changes to the Fund’s investment objectives or policies that have not been approved by shareholders or in the principal risk factors associated with an investment in the Fund. Investment Objective The Fund’s primary investment objective is long term growth of capital and income. The Fund will invest at least 80% of its net assets (plus borrowings made for investment purposes), under normal market conditions, in common stocks and other securities of foreign and domestic companies involved in providing products, services, or equipment for (i) the generation or distribution of electricity, gas, and water and (ii) telecommunications services or infrastructure operations (collectively, the “Utility Industry”). A company will be considered to be in the Utility Industry if it derives at least 50% of its revenues or earnings from, or devotes at least 50% of its assets to, the indicated activities or utility-related activities. The remaining 20% of its assets may be invested in other securities including stocks, equity securities, debt obligations and money market instruments, as well as certain derivative instruments in the Utility Industry or other industries. Moreover, should extraordinary conditions affecting such sectors or securities markets as a whole warrant, the Fund may temporarily be primarily invested in money market instruments. When the Fund is invested in these instruments for temporary or defensive purposes it may not achieve its investment objective. The investment policy of the Fund relating to the type of securities in which at least 80% of the Fund’s net assets (plus borrowings made for investment purposes) must be invested may be changed by the Board without shareholder approval. Shareholders will, however, receive at least 60 days prior notice of any change in this policy. Although many companies in the Utility Industry traditionally pay above average dividends, the Fund intends to focus on those companies whose securities have the potential to increase in value. The Fund’s performance is expected to reflect conditions affecting public utility industries. These industries are sensitive to factors such as interest rates, local and national government regulations, the price and availability of fuel, environmental protection or energy conservation regulations, weather, the level of demand for services, and the risks associated with constructing and operating nuclear power facilities. These factors may change rapidly. The Fund emphasizes quality in selecting utility investments, and generally looks for companies that have proven dividend records and sound financial structures. Believing that the industry is under consolidation due to changes in regulation, the Fund intends to position itself to take advantage of trends in consolidation. Under normal circumstances the Fund will invest in securities of issuers located in countries other than the United States and may invest in such foreign securities without limitation. Among the foreign securities in which the Fund may invest are those issued by companies located in emerging markets. Investing in securities of foreign issuers, which generally are denominated in foreign currencies, may involve certain risk and opportunity considerations not typically associated with investing in domestic companies and could cause the Fund to be affected favorably or unfavorably by changes in currency exchange rates and revaluations of currencies. The Fund may invest in securities across all market capitalization ranges. No assurance can be given that the Fund’s investment objective will be achieved. Investment Methodology of the Fund In selecting securities for the Fund, Gabelli Funds, LLC (the “Investment Adviser”) normally will consider the following factors, among others: ● the Investment Adviser’s own evaluations of the private market value (as defined below), cash flow, earnings per share and other fundamental aspects of the underlying assets and business of the company; ● the potential for capital appreciation of the securities; ● the interest or dividend income generated by the securities; ● the prices of the securities relative to other comparable securities; ● whether the securities are entitled to the benefits of call protection or other protective covenants; ● the existence of any anti-dilution protections or guarantees of the security; and ● the diversification of the portfolio of the Fund as to issuers. The Investment Adviser’s investment philosophy with respect to equity securities is to identify assets that are selling in the public market at a discount to their private market value. The Investment Adviser defines private market value as the value informed purchasers are willing to pay to acquire assets with similar characteristics. The Investment Adviser also normally evaluates an issuer’s free cash flow and long-term earnings trends. Finally, the Investment Adviser looks for a catalyst, something indigenous to the company, its industry or country that will surface additional value. Certain Investment Practices Corporate Reorganizations. Temporary Defensive Investments. agencies and instrumentalities of the United States government, such as the Government National Mortgage Association, are supported by the “full faith and credit” of the United States government; others, such as those of the Export-Import Bank of the United States, are supported by the right of the issuer to borrow from the United States Treasury; others, such as those of the Federal National Mortgage Association, are supported by the discretionary authority of the United States government to purchase the agency’s obligations; and still others, such as those of the Student Loan Marketing Association, are supported only by the credit of the instrumentality. No assurance can be given that the United States government would provide financial support to United States government sponsored instrumentalities if it is not obligated to do so by law. During temporary defensive periods, the Fund may not achieve its investment objective. Non-Investment Grade Securities. Generally, such non-investment grade securities and unrated securities of comparable quality offer a higher current yield than is offered by higher rated securities, but also (i) will likely have some quality and protective characteristics that, in the judgment of the rating organizations, are outweighed by large uncertainties or major risk exposures to adverse conditions and (ii) are predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal in accordance with the terms of the obligation. The market values of certain of these securities also tend to be more sensitive to individual corporate developments and changes in economic conditions than higher quality securities. In addition, such securities generally present a higher degree of credit risk. The risk of loss due to default by these issuers is significantly greater because such non-investment grade securities and unrated securities of comparable quality generally are unsecured and frequently are subordinated to the prior payment of senior indebtedness. In light of these risks, the Investment Adviser, in evaluating the creditworthiness of an issue, whether rated or unrated, will take various factors into consideration, which may include, as applicable, the issuer’s operating history, financial resources and its sensitivity to economic conditions and trends, the market support for the facility financed by the issue, the perceived ability and integrity of the issuer’s management and regulatory matters. In addition, the market value of non-investment grade securities is more volatile than that of higher quality securities, and the markets in which such non-investment grade or unrated securities are traded are more limited than those in which higher rated securities are traded. The existence of limited markets may make it more difficult for the Fund to obtain accurate market quotations for purposes of valuing its portfolio and calculating its net asset value (“NAV”). Moreover, the lack of a liquid trading market may restrict the availability of securities for the Fund to purchase and may also have the effect of limiting the ability of the Fund to sell securities at their fair value in response to changes in the economy or the financial markets. Non-investment grade securities also present risks based on payment expectations. If an issuer calls the obligation for redemption (often a feature of fixed income securities), the Fund may have to replace the security with a lower yielding security, resulting in a decreased return for investors. Also, as the principal value of nonconvertible bonds and preferred stocks moves inversely with movements in interest rates, when interest rates rise, the value of the securities held by the Fund may decline proportionately more than a portfolio consisting of higher rated securities. Investments in zero coupon bonds may be more speculative and subject to greater fluctuations in value due to changes in interest rates than bonds that pay regular income streams. The Fund may be subject to a greater risk of rising interest rates due to the recent period of historically low interest rates. The Federal Reserve has recently begun to raise the federal funds rate as part of its efforts to address rising inflation. There is a risk that interest rates will continue to rise, which will likely drive down prices of bonds and other fixed-income securities. The magnitude of these price reductions in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s NAV. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by the Investment Adviser. As part of its investment in non-investment grade securities, the Fund may invest in securities of issuers in default. The Fund will make an investment in securities of issuers in default only when the Investment Adviser believes that such issuers will honor their obligations or emerge from bankruptcy protection under a plan pursuant to which the securities received by the Fund in exchange for its defaulted securities will have a value in excess of the Fund’s investment. By investing in securities of issuers in default, the Fund bears the risk that these issuers will not continue to honor their obligations or emerge from bankruptcy protection or that the value of the securities will not otherwise appreciate. In addition to using recognized rating agencies and other sources, the Investment Adviser also performs its own analysis of issues in seeking investments that it believes to be underrated (and thus higher yielding) in light of the financial condition of the issuer. Its analysis of securities of issuers may include, among other things, current and anticipated cash flow and borrowing requirements, value of assets in relation to historical cost, strength of management, responsiveness to business conditions, credit standing, and current anticipated results of operations. In selecting investments for the Fund, the Investment Adviser may also consider general business conditions, anticipated changes in interest rates, and the outlook for specific industries. Subsequent to its purchase by the Fund, an issuer of securities may cease to be rated or its rating may be reduced. In addition, it is possible that statistical rating agencies may change their ratings of a particular issuer to reflect subsequent events. Moreover, such ratings do not assess the risk of a decline in market value. None of these events will require the sale of the securities by the Fund, although the Investment Adviser will consider these events in determining whether the Fund should continue to hold the securities. The market for non-investment grade and comparable unrated securities has experienced several periods of significantly adverse price and liquidity, particularly at or around times of economic recessions. Past market recessions have adversely affected the value of such securities as well as the ability of certain issuers of such securities to repay principal and pay interest thereon or to refinance such securities. The market for those securities may react in a similar fashion in the future. Options. the-counter (“OTC”) markets as a means of achieving additional return or of hedging the value of the Fund’s portfolio. The Fund may write covered call options on common stocks that it owns or has an immediate right to acquire through conversion or exchange of other securities in an amount not to exceed 25% of its total assets or invest up to 10% of its total assets in the purchase of put options on common stocks that the Fund owns or may acquire through the conversion or exchange of other securities that it owns. A call option is a contract that gives the holder of the option the right to buy from the writer (seller) of the call option, in return for a premium paid, the security underlying the option at a specified exercise price at any time during the term of the option. The writer of the call option has the obligation upon exercise of the option to deliver the underlying security upon payment of the exercise price during the option period. A put option is a contract that gives the holder of the option the right to sell to the writer (seller), in return for the premium, the underlying security at a specified price during the term of the option. The writer of the put, who receives the premium, has the obligation to buy the underlying security upon exercise, at the exercise price during the option period. If the Fund has written an option, it may terminate its obligation by effecting a closing purchase transaction. This is accomplished by purchasing an option of the same series as the option previously written. There can be no assurance that a closing purchase transaction can be effected when the Fund so desires. An exchange-traded option may be closed out only on an exchange which provides a secondary market for an option of the same series. Although the Fund will generally purchase or write only those options for which there appears to be an active secondary market, there is no assurance that a liquid secondary market on an exchange will exist for any particular option. A call option is “covered” if the Fund owns the underlying instrument covered by the call or has an absolute and immediate right to acquire that instrument without additional cash consideration upon conversion or exchange of another instrument held in its portfolio (or for additional cash consideration held in a segregated account by its custodian). A call option is also covered if the Fund holds a call on the same instrument as the call written where the exercise price of the call held is (i) equal to or less than the exercise price of the call written or (ii) greater than the exercise price of the call written if the difference is maintained by the Fund in cash, U.S. government obligations or other high-grade short term obligations in a segregated account with its custodian. A put option is “covered” if the Fund maintains cash or other high-grade short term obligations with a value equal to the exercise price in a segregated account with its custodian, or else holds a put on the same instrument as the put written where the exercise price of the put held is equal to or greater than the exercise price of the put written. If the Fund has written an option, it may terminate its obligation by effecting a closing purchase transaction. This is accomplished by purchasing an option of the same series as the option previously written. However, once the Fund has been assigned an exercise notice, it will be unable to effect a closing purchase transaction. Similarly, if the Fund is the holder of an option, it may liquidate its position by effecting a closing sale transaction. This is accomplished by selling an option with the same terms as the option previously purchased. There can be no assurance that either a closing purchase or sale transaction can be effected when the Fund so desires. The Fund will realize a profit from a closing transaction if the price of the transaction is less than the premium it received from writing the option or is more than the premium it paid to purchase the option; the Fund will realize a loss from a closing transaction if the price of the transaction is more than the premium it received from writing the option or is less than the premium it paid to purchase the option. Since call option prices generally reflect increases in the price of the underlying security, any loss resulting from the repurchase of a call option may also be wholly or partially offset by unrealized appreciation of the underlying security. Other principal factors affecting the market value of a put or a call option include supply and demand, interest rates, the current market price and price volatility of the underlying security and the time remaining until the expiration date. Gains and losses on investments in options depend, in part, on the ability of the Investment Adviser to predict correctly the effect of these factors. The use of options cannot serve as a complete hedge since the price movement of securities underlying the options will not necessarily follow the price movements of the portfolio securities subject to the hedge. An option position may be closed out only on an exchange that provides a secondary market for an option with the same terms or in a private transaction. Although the Fund will generally purchase or write only those options for which there appears to be an active secondary market, there is no assurance that a liquid secondary market on an exchange will exist for any particular option. In such event, it might not be possible to effect closing transactions in particular options, so that the Fund would have to exercise its options in order to realize any profit and would incur brokerage commissions upon the exercise of call options and upon the subsequent disposition of underlying securities for the exercise of put options. If the Fund, as a covered call option writer, is unable to effect a closing purchase transaction in a secondary market, it will not be able to sell the underlying security until the option expires or it delivers the underlying security upon exercise or otherwise covers the position. In addition to options on securities, the Fund may also purchase and sell call and put options on securities indices. A stock index reflects in a single number the market value of many different stocks. Relative values are assigned to the stocks included in an index and the index fluctuates with changes in the market values of the stocks. The options give the holder the right to receive a cash settlement during the term of the option based on the difference between the exercise price and the value of the index. By writing a put or call option on a securities index, the Fund is obligated, in return for the premium received, to make delivery of this amount. The Fund may offset its position in the stock index options prior to expiration by entering into a closing transaction on an exchange or it may let the option expire unexercised. The Fund may also buy or sell put and call options on foreign currencies. A put option on a foreign currency gives the purchaser of the option the right to sell a foreign currency at the exercise price until the option expires. A call option on a foreign currency gives the purchaser of the option the right to purchase the currency at the exercise price until the option expires. Currency options traded on U.S. or other exchanges may be subject to position limits which may limit the ability of the Fund to reduce foreign currency risk using such options. OTC options differ from exchange-traded options in that they are two-party contracts with price and other terms negotiated between buyer and seller and generally do not have as much market liquidity as exchange-traded options. OTC options are considered illiquid securities. Use of options on securities indices entails the risk that trading in the options may be interrupted if trading in certain securities included in the index is interrupted. The Fund will not purchase these options unless the Investment Adviser is satisfied with the development, depth and liquidity of the market and the Investment Adviser believes the options can be closed out. Price movements in the portfolio of the Fund may not correlate precisely with the movements in the level of an index and, therefore, the use of options on indices cannot serve as a complete hedge and will depend, in part, on the ability of the Investment Adviser to predict correctly movements in the direction of the stock market generally or of a particular industry. Because options on securities indices require settlement in cash, the Fund may be forced to liquidate portfolio securities to meet settlement obligations. Although the Investment Adviser will attempt to take appropriate measures to minimize the risks relating to the Fund’s writing of put and call options, there can be no assurance that the Fund will succeed in any option writing program it undertakes. Futures Contracts and Options on Futures. An option on a futures contract gives the purchaser the right, in return for the premium paid, to assume a position in a futures contract at a specified exercise price at any time prior to the expiration of the option. Upon exercise of an option, the delivery of the futures position by the writer of the option to the holder of the option will be accompanied by delivery of the accumulated balance in the writer’s futures margin account attributable to that contract, which represents the amount by which the market price of the futures contract exceeds, in the case of a call option, or is less than, in the case of a put option, the exercise price of the option on the futures contract. The potential loss related to the purchase of an option on a futures contract is limited to the premium paid for the option (plus transaction costs). Because the value of the option purchased is fixed at the point of sale, there are no daily cash payments by the purchaser to reflect changes in the value of the underlying contract; however, the value of the option does change daily and that change would be reflected in the net assets of the Fund. Futures and options on futures entail certain risks, including but not limited to the following: no assurance that futures contracts or options on futures can be offset at favorable prices, possible reduction of the yield of the Fund due to the use of hedging, possible reduction in value of both the securities hedged and the hedging instrument, possible lack of liquidity due to daily limits on price fluctuations, imperfect correlation between the contracts and the securities being hedged and losses from investing in futures transactions that are potentially unlimited. The Investment Adviser has claimed an exclusion, granted to operators of registered investment companies like the Fund, from registration as a commodity pool operator (“CPO”) with respect to the Fund under the Commodity Exchange Act (the “CEA”), and, therefore, is not subject to registration or regulation with respect to the Fund under the CEA. As a result, the Fund is limited in its ability to use commodity futures (which include futures on broad-based securities indices and interest rate futures) or options on commodity futures, engage in certain swaps transactions or make certain other investments (whether directly or indirectly through investments in other investment vehicles) for purposes other than “bona fide hedging,” as defined in the rules of the Commodity Futures Trading Commission. With respect to transactions other than for bona fide hedging purposes, either: (1) the aggregate initial margin and premiums required to establish the Fund’s positions in such investments may not exceed 5% of the liquidation value of its portfolio (after accounting for unrealized profits and unrealized losses on any such investments); or (2) the aggregate net notional value of such instruments, determined at the time the most recent position was established, may not exceed 100% of the liquidation value of its portfolio (after accounting for unrealized profits and unrealized losses on any such positions). In addition to meeting one of the foregoing trading limitations, the Fund may not market itself as a commodity pool or otherwise as a vehicle for trading in the futures, options or swaps markets. If the Investment Adviser were required to register as a CPO with respect to the Fund, compliance with additional registration and regulatory requirements would increase Fund expenses. Other potentially adverse regulatory initiatives could also develop. Interest Rate Futures Contracts and Options Thereon. Similarly, the Fund may purchase interest rate futures contracts when it is expected that interest rates may decline. The purchase of futures contracts for this purpose constitutes a hedge against increases in the price of debt securities (caused by declining interest rates) which the Fund intends to acquire. Since fluctuations in the value of appropriately selected futures contracts should approximate that of the debt securities that will be purchased, the Fund can take advantage of the anticipated rise in the cost of the debt securities without actually buying them. Subsequently, the Fund can make its intended purchase of the debt securities in the cash market and concurrently liquidate its futures position. The purchase of a call option on a futures contract is similar in some respects to the purchase of a call option on an individual security. Depending on the pricing of the option compared to either the price of the futures contract upon which it is based or the price of the underlying debt securities, it may or may not be less risky than ownership of the futures contract or underlying debt securities. As with the purchase of futures contracts, when the Fund is not fully invested it may purchase a call option on a futures contract to hedge against a market advance due to declining interest rates. The purchase of a put option on a futures contract is similar to the purchase of protective put options on portfolio securities. The Fund will purchase a put option on a futures contract to hedge the Fund’s portfolio against the risk of rising interest rates and a consequent reduction in the value of portfolio securities. The writing of a call option on a futures contract constitutes a partial hedge against declining prices of the securities that are deliverable upon exercise of the futures contract. If the futures price at expiration of the option is below the exercise price, the Fund will retain the full amount of the option premium, which provides a partial hedge against any decline that may have occurred in the Fund’s portfolio holdings. The writing of a put option on a futures contract constitutes a partial hedge against increasing prices of the securities that are deliverable upon exercise of the futures contract. If the futures price at expiration of the option is higher than the exercise price, the Fund will retain the full amount of the option premium, which provides a partial hedge against any increase in the price of debt securities that the Fund intends to purchase. If a put or call option the Fund has written is exercised, the Fund will incur a loss which will be reduced by the amount of the premium it received. Depending on the degree of correlation between changes in the value of its portfolio securities and changes in the value of its futures positions, losses of the Fund from options on futures it has written may to some extent be reduced or increased by changes in the value of its portfolio securities. Swap Contracts. Securities Index Futures Contracts and Options Thereon. portfolio that might otherwise result. If such decline occurs, the loss in value of portfolio securities may be offset, in whole or part, by gains on the futures position. When the Fund is not fully invested in the securities market and anticipates a significant market advance, it may purchase securities index futures contracts in order to gain rapid market exposure that may, in part or entirely, offset increases in the cost of securities that it intends to purchase. As such purchases are made, the corresponding positions in securities index futures contracts will be closed out. The Fund may write put and call options on securities index futures contracts for hedging purposes. Currency Futures and Options Thereon. The purchase of options on currency futures will allow the Fund, for the price of the premium and related transaction costs it must pay for the option, to decide whether or not to buy (in the case of a call option) or to sell (in the case of a put option) a futures contract at a specified price at any time during the period before the option expires. If the Investment Adviser, in purchasing an option, has been correct in its judgment concerning the direction in which the price of a foreign currency would move as against the U.S. dollar, the Fund may exercise the option and thereby take a futures position to hedge against the risk it had correctly anticipated or close out the option position at a gain that will offset, to some extent, currency exchange losses otherwise suffered by the Fund. If exchange rates move in a way the Fund did not anticipate, however, the Fund will have incurred the expense of the option without obtaining the expected benefit; any such movement in exchange rates may also thereby reduce, rather than enhance, the Fund’s profits on its underlying securities transactions. Forward Currency Exchange Contracts. At or before the maturity of a forward sale contract, the Fund may either sell a portfolio security and make delivery of the currency, or retain the security and offset its contractual obligations to deliver the currency by purchasing a second contract pursuant to which the Fund will obtain, on the same maturity date, the same amount of the currency which it is obligated to deliver. If the Fund retains the portfolio security and engages in an offsetting transaction, the Fund, at the time of execution of the offsetting transaction, will incur a gain or a loss to the extent that movement has occurred in forward contract prices. Should forward prices decline during the period between entering into a forward contract by the Fund for the sale of a currency and the date it enters into an offsetting contract for the purchase of the currency, the Fund will realize a gain to the extent the price of the currency it has agreed to purchase is less than the price of the currency it has agreed to sell. Should forward prices increase, the Fund will suffer a loss to the extent the price of the currency it has agreed to purchase exceeds the price of the currency it has agreed to sell. Closing out forward purchase contracts involves similar offsetting transactions. The cost to the Fund of engaging in currency transactions varies with factors such as the currency involved, the length of the contract period and the market conditions then prevailing. Because forward transactions in currency exchange are usually conducted on a principal basis, no fees or commissions are involved. The use of foreign currency contracts does not eliminate fluctuations in the underlying prices of the securities, but it does establish a rate of exchange that can be achieved in the future. In addition, although forward currency contracts limit the risk of loss due to a decline in the value of the hedged currency, they also limit any potential gain that might result if the value of the currency increases. If a decline in any currency is generally anticipated by the Investment Adviser, the Fund may not be able to contract to sell the currency at a price above the level to which the currency is anticipated to decline. When Issued, Delayed Delivery Securities and Forward Commitments. Securities purchased under a forward commitment are subject to market fluctuation, and no interest (or dividends) accrues to the Fund prior to the settlement date. Short Sales Against the Box. To secure its obligations to deliver the securities sold short, the Fund will deposit in escrow in a separate account with its custodian an equal a
Risk Factors [Table Text Block]									Risk Factors and Special Considerations Investors should consider the following risk factors and special considerations associated with investing in the Fund: Utility Industry Risks Under normal market conditions, the Fund will invest at least 80% of its net assets (plus borrowings made for investment purposes) in foreign and domestic companies involved in the Utility Industry and, as a result, the value of the common shares will be more susceptible to factors affecting those particular types of companies, including governmental regulation, inflation, cost increases in fuel and other operating expenses, technological innovations that may render existing products and equipment obsolete and increasing interest rates resulting in high interest costs on borrowings needed for capital construction programs, including costs associated with compliance with environmental and other regulations. Sector Risk. Government Regulation. any given regulatory agency may make major shifts in policy from time to time. There is no assurance that regulatory authorities will, in the future, permit companies to implement rate increases or that such increases will be adequate to permit the payment of dividends on such issuer’s common shares. Additionally, existing and possible future regulatory legislation may make it even more difficult for companies in the Utility Industry to obtain adequate relief from rate regulation. Regulatory considerations limit the percentage of the shares of a public utility held by a fund or by an adviser and its affiliates on behalf of all their clients. Various types of ownership restrictions are imposed by the Federal Communications Commission (“FCC”) on investment in media companies and cellular licensees. These rules limit the number of broadcast stations both locally and nationally that a single entity is permitted to own, operate, or control and prohibit ownership of certain competitive communications providers in the same location. The FCC also applies limited ownership restrictions on cellular licensees serving rural areas. Attributable interests that may result from the role of the Investment Adviser and its principals in connection with other funds, managed accounts and companies may limit the Fund’s ability to invest in certain mass media and cellular companies. These limitations may unfavorably restrict the ability of the Fund to make certain investments. Deregulation. Financing. Equipment and Supplies. availability of fuel (such as oil, coal, nuclear or natural gas) also may adversely affect the profitability of utility companies. Electric utilities may be burdened by unexpected increases in operating costs. They may also be negatively affected when long term interest rates rise. Long term borrowings are used to finance most utility investments, and rising interest rates lead to higher financing costs and reduced earnings. There are also the considerable costs associated with environmental compliance, nuclear waste clean-up, cap and trade or other programs designed to reduce carbon dioxide and other greenhouse emissions, and safety regulation. Increasingly, regulators are calling upon electric utilities to bear these added costs, and there is a risk that these costs will not be fully recovered through an increase in revenues. Among gas companies, there has been a move to diversify into oil and gas exploration and development, making investment returns more sensitive to energy prices. In the case of the water utility sector, the industry is highly fragmented, and most water supply companies find themselves in mature markets, although upgrading of fresh water and waste water systems is an expanding business. Long Term Objective: Not a Complete Investment Program The Fund is intended for investors seeking long term capital growth and income. The Fund is not meant to provide a vehicle for those who wish to exploit short term swings in the stock market. An investment in shares of the Fund should not be considered a complete investment program. Each shareholder should take into account the Fund’s investment objective as well as the shareholder’s other investments when considering an investment in the Fund. Market Value and Net Asset Value The Fund is a diversified, closed-end management investment company. Shares of closed-end funds are bought and sold in the securities markets and may trade at either a premium to or discount from NAV. Listed shares of closed-end investment companies often trade at discounts from NAV. This characteristic of shares of a closed-end fund is a risk separate and distinct from the risk that its NAV may decrease. The Fund cannot predict whether its listed shares will trade at, below or above NAV. The risk of holding shares of a closed-end fund that might trade at a discount is more pronounced for shareholders who wish to sell their shares in a relatively short period of time after acquiring them because, for those investors, realization of a gain or loss on their investments is likely to be more dependent upon the existence of a premium or discount than upon portfolio performance. The Fund’s shares are not subject to redemption. Shortly after the inception of the Fund, the market price of the Fund exceeded the NAV and the premium continues today. Shareholders desiring liquidity may, subject to applicable securities laws, trade their Fund shares on the New York Stock Exchange (“NYSE”) or other markets on which such shares may trade at the then-current market value, which may differ from the then-current NAV. Shareholders will incur brokerage or other transaction costs to sell shares. Non-Investment Grade Securities The Fund may invest up to 25% of its total assets in fixed income securities rated below investment grade by recognized statistical rating agencies or unrated securities of comparable quality. These securities, which may be preferred stock or debt, are predominantly speculative and involve major risk exposure to adverse conditions. Debt securities that are not rated or that are rated lower than “BBB” by S&P or lower than “Baa” by Moody’s are referred to in the financial press as “junk bonds.” Such securities are subject to greater risks than investment grade securities, which reflect their speculative character, including the following: ● greater volatility; ● greater credit risk; ● potentially greater sensitivity to general economic or industry conditions; ● potential lack of attractive resale opportunities (illiquidity); and ● additional expenses to seek recovery from issuers who default. Fixed income securities purchased by the Fund may be rated as low as C by Moody’s or D by S&P or may be unrated securities considered to be of equivalent quality. Securities that are rated C by Moody’s are the lowest rated class and can be regarded as having extremely poor prospects of ever obtaining investment-grade standing. Debt rated D by S&P is in default or is expected to default upon maturity of payment date. The market value of non-investment grade securities may be more volatile than the market value of higher rated securities and generally tends to reflect the market’s perception of the creditworthiness of the issuer and short term market developments to a greater extent than more highly rated securities, which primarily reflect fluctuations in general levels of interest rates. Generally, such non-investment grade securities and unrated securities of comparable quality offer a higher current yield than is offered by higher rated securities, but also (i) will likely have some quality and protective characteristics that, in the judgment of the rating organizations, are outweighed by large uncertainties or major risk exposures to adverse conditions and (ii) are predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal in accordance with the terms of the obligation. The market values of certain of these securities also tend to be more sensitive to individual corporate developments and changes in economic conditions than higher quality securities. In addition, such securities generally present a higher degree of credit risk. The risk of loss due to default by these issuers is significantly greater because such non-investment grade securities and unrated securities of comparable quality generally are unsecured and frequently are subordinated to the prior payment of senior indebtedness. In light of these risks, the Investment Adviser, in evaluating the creditworthiness of an issue, whether rated or unrated, will take various factors into consideration, which may include, as applicable, the issuer’s operating history, financial resources and its sensitivity to economic conditions and trends, the market support for the facility financed by the issue, the perceived ability and integrity of the issuer’s management, and regulatory matters. Non-investment grade securities also present risks based on payment expectations. If an issuer calls the obligation for redemption (often a feature of fixed income securities), the Fund may have to replace the security with a lower yielding security, resulting in a decreased return for investors. Also, as the principal value of nonconvertible bonds and preferred stocks moves inversely with movements in interest rates, in the event of rising interest rates the value of the securities held by the Fund may decline proportionately more than a portfolio consisting of higher rated securities. Investments in zero coupon bonds may be more speculative and subject to greater fluctuations in value due to changes in interest rates than bonds that pay regular income streams. Ratings are relative and subjective, and are not absolute standards of quality. Securities ratings are based largely on the issuer’s historical financial condition and the rating agencies’ analysis at the time of rating. Consequently, the rating assigned to any particular security is not necessarily a reflection of the issuer’s current financial condition. As part of its investment in non-investment grade securities, the Fund may invest in securities of issuers in default. The Fund will make an investment in securities of issuers in default only when the Investment Adviser believes that such issuers will honor their obligations or emerge from bankruptcy protection under a plan pursuant to which the securities received by the Fund in exchange for its defaulted securities will have a value in excess of the Fund’s investment. By investing in securities of issuers in default, the Fund bears the risk that these issuers will not continue to honor their obligations or emerge from bankruptcy protection or that the value of the securities will not otherwise appreciate. Equity Risk Investing in the Fund involves equity risk, which is the risk that the securities held by the Fund will fall in market value due to adverse market and economic conditions, perceptions regarding the industries in which the issuers of securities held by the Fund participate and the particular circumstances and performance of particular companies whose securities the Fund holds. An investment in the Fund represents an indirect economic stake in the securities owned by the Fund, which are for the most part traded on securities exchanges or in the OTC markets. The market value of these securities, like other market investments, may move up or down, sometimes rapidly and unpredictably. The NAV of the Fund may at any point in time be worth less than the amount at the time the shareholder invested in the Fund, even after taking into account any reinvestment of distributions. Foreign Securities The Fund may invest its assets in foreign securities without limitation, including securities of issuers whose primary operations or principal trading market is in an “emerging market.” Investments in the securities of foreign issuers involve certain considerations and risks not ordinarily associated with investments in securities of domestic issuers and such securities may be more volatile than those of issuers in the United States. Foreign companies are not generally subject to uniform accounting, auditing and financial standards and requirements comparable to those applicable to United States companies. Foreign securities exchanges, brokers and listed companies may be subject to less government supervision and regulation than exists in the United States. Dividend and interest income may be subject to withholding and other foreign taxes, which may adversely affect the net return on such investments. There may be difficulty in obtaining or enforcing a court judgment abroad. In addition, it may be difficult to effect repatriation of capital invested in certain countries. Also, with respect to certain countries, there are risks of expropriation, confiscatory taxation, political or social instability or diplomatic developments that could affect assets of the Fund held in foreign countries. Dividend income that the Fund receives from foreign securities may not be eligible for the special tax treatment applicable to qualified dividend income. Moreover, certain equity investments in foreign issuers classified as passive foreign investment companies may be subject to additional taxation risk. There may be less publicly available information about a foreign company than a United States company. Foreign securities markets may have substantially less volume than United States securities markets and some foreign company securities are less liquid than securities of otherwise comparable United States companies. A portfolio of foreign securities may also be adversely affected by fluctuations in the rates of exchange between the currencies of different nations and by exchange control regulations. Foreign markets also have different clearance and settlement procedures that could cause the Fund to encounter difficulties in purchasing and selling securities on such markets and may result in the Fund missing attractive investment opportunities or experiencing loss. In addition, a portfolio that includes foreign securities can expect to have a higher expense ratio because of the increased transaction costs on non-United States securities markets and the increased costs of maintaining the custody of foreign securities. The Fund also may purchase sponsored American Depositary Receipts (“ADRs”) or United States dollar denominated securities of foreign issuers. ADRs are receipts issued by United States banks or trust companies in respect of securities of foreign issuers held on deposit for use in the United States securities markets. While ADRs may not necessarily be denominated in the same currency as the securities into which they may be converted, many of the risks associated with foreign securities may also apply to ADRs. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts, or to pass through to them any voting rights with respect to the deposited securities. Emerging Markets An “emerging market” country is any country that is considered to be an emerging or developing country by the International Bank for Reconstruction and Development. Investing in securities of companies in emerging markets may entail special risks relating to potential political and economic instability and the risks of expropriation, nationalization, confiscation or the imposition of restrictions on foreign investment, the lack of hedging instruments and restrictions on repatriation of capital invested. Emerging securities markets are substantially smaller, less developed, less liquid and more volatile than the major securities markets. The limited size of emerging securities markets and limited trading value compared to the volume of trading in U.S. securities could cause prices to be erratic for reasons apart from factors that affect the quality of the securities. For example, limited market size may cause prices to be unduly influenced by traders who control large positions. Adverse publicity and investors’ perceptions, whether or not based on fundamental analysis, may decrease the value and liquidity of portfolio securities, especially in these markets. Other risks include high concentration of market capitalization and trading volume in a small number of issuers representing a limited number of industries, as well as a high concentration of investors and financial intermediaries; overdependence on exports, including gold and natural resources exports, making these economies vulnerable to changes in commodity prices; overburdened infrastructure and obsolete or unseasoned financial systems; environmental problems; potential for sanctions; less developed legal systems, and deficiencies in regulatory oversight, market infrastructure, shareholder protections; differences in regulatory, accounting, auditing and financial reporting and recordkeeping standards; and less reliable securities custodial services and settlement practices. Small- and Mid-Cap Stock Risk The Fund may invest in companies with small or medium capitalizations. Smaller and medium company stocks can be more volatile than, and perform differently from, larger company stocks. There may be less trading in a smaller or medium company’s stock, which means that buy and sell transactions in that stock could have a larger impact on the stock’s price than is the case with larger company stocks. Smaller and medium company stocks may be particularly sensitive to changes in interest rates, borrowing costs and earnings. Smaller and medium companies may have fewer business lines; changes in any one line of business, therefore, may have a greater impact on a smaller and medium company’s stock price than is the case for a larger company. As a result, the purchase or sale of more than a limited number of shares of a small and medium company may affect its market price. The Fund may need a considerable amount of time to purchase or sell its positions in these securities. In addition, smaller or medium company stocks may not be well known to the investing public. Special Risks of Derivative Transactions The Fund may participate in derivative transactions. Such transactions entail certain execution, market, liquidity, hedging and tax risks. Participation in the options, futures or swaps markets and in currency exchange transactions involves investment risks and transaction costs to which the Fund would not be subject absent the use of these strategies. If the Investment Adviser’s prediction of movements in the direction of the securities, foreign currency and interest rate markets are inaccurate, the consequences to the Fund may leave the Fund in a worse position than if such strategies were not used. Risks inherent in the use of options, foreign currency, swaps contracts, futures contracts and options on futures contracts, swap contracts, securities indices and foreign currencies include: ● dependence on the Investment Adviser’s ability to predict correctly movements in the direction of interest rates, securities prices and currency markets; ● imperfect correlation between the price of options and futures contracts and options thereon and move-ments in the prices of the securities or currencies being hedged; ● the fact that skills needed to use these strategies are different from those needed to select portfolio securities; ● the possible absence of a liquid secondary market for any particular instrument at any time; ● the possible need to defer closing out certain hedged positions to avoid adverse tax consequences; ● the possible inability of the Fund to purchase or sell a security at a time that otherwise would be favorable for it to do so; and ● the creditworthiness of counterparties. Options, futures contracts, swaps contracts, and options thereon and forward contracts on securities and currencies may be traded on foreign exchanges. Such transactions may not be regulated as effectively as similar transactions in the United States, may not involve a clearing mechanism and related guarantees, and are subject to the risk of governmental actions affecting trading in, or the prices of, foreign securities. The value of such positions also could be adversely affected by (i) other complex foreign political, legal and economic factors, (ii) lesser availability than in the United States of data on which to make trading decisions, (iii) delays in the ability of the Fund to act upon economic events occurring in the foreign markets during non-business hours in the United States, (iv) the imposition of different exercise and settlement terms and procedures and margin requirements than in the United States and (v) less trading volume. Exchanges on which options, futures, swaps and options on futures or swaps are traded may impose limits on the positions that the Fund may take in certain circumstances. Many OTC derivatives are valued on the basis of dealers’ pricing of these instruments. However, the price at which dealers value a particular derivative and the price which the same dealers would actually be willing to pay for such derivative should the Fund wish or be forced to sell such position may be materially different. Such differences can result in an overstatement of the Fund’s NAV and may materially adversely affect the Fund in situations in which the Fund is required to sell derivative instruments. Exchange-traded derivatives and OTC derivative transactions submitted for clearing through a central counterparty have become subject to minimum initial and variation margin requirements set by the relevant clearinghouse, as well as possible margin requirements mandated by the SEC or the Commodity Futures Trading Commission. These regulators also have broad discretion to impose margin requirements on non-cleared OTC derivatives. These margin requirements will increase the overall costs for the Fund. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. Derivatives may give rise to a form of leverage and may expose the Fund to greater risk and increase its costs. Under Rule 18f-4 under the 1940 Act, among other things, the Fund must either use derivatives in a limited manner or comply with an outer limit on fund leverage risk based on value-at-risk. See “—Derivatives Transactions Subject to Rule18f-4 Under the 1940 Act” below. Derivatives Transactions Subject to Rule 18f-4 Under the 1940 Act Under Rule 18f-4, “Derivatives Transactions” include the following: (i) any swap, security-based swap (including a contract for differences), futures contract, forward contract, option (excluding purchased options), any combination of the foregoing, or any similar instrument, under which the Fund is or may be required to make any payment or delivery of cash or other assets during the life of the instrument or at maturity or early termination, whether as margin or settlement payment or otherwise; (ii) any short sale borrowing; (iii) reverse repurchase agreements and similar financing transactions, if the Fund elects to treat these transactions as Derivatives Transactions under Rule 18f-4; and (iv) when-issued or forward-settling securities (e.g., firm and standby commitments, including to-be-announced commitments, and dollar rolls) and non-standard settlement cycle securities, unless the Fund intends to physically settle the transaction and the transaction will settle within 35 days of its trade date. Unless the Fund is relying on the Limited Derivatives User Exception (as defined below), the Fund must comply with Rule 18f-4 with respect to its Derivatives Transactions. Rule 18f-4, among other things, requires the Fund to (i) appoint a Derivatives Risk Manager; (ii) maintain a Derivatives Risk Management Program designed to identify, assess, and reasonably manage the risks associated with Derivatives Transactions; (iii) comply with certain value-at-risk (VaR)-based leverage limits (VaR is an estimate of an instrument’s or portfolio’s potential losses over a given time horizon and at a specified confidence level); and (iv) comply with certain Board reporting and recordkeeping requirements. Rule 18f-4 provides an exception from the requirements to appoint a Derivatives Risk Manager, adopt a Derivatives Risk Management Program, comply with certain VaR-based leverage limits, and comply with certain Board oversight and reporting requirements if the Fund’s “derivatives exposure” (as defined in Rule 18f-4) is limited to 10% of its net assets (as calculated in accordance with Rule 18f-4) and the Fund adopts and implements written policies and procedures reasonably designed to manage its derivatives risks (the “Limited Derivatives User Exception”). Pursuant to Rule 18f-4, if the Fund enters into reverse repurchase agreements or similar financing transactions, the Fund will (i) aggregate the amount of indebtedness associated with all of its reverse repurchase agreements or similar financing transactions with the amount of any other “senior securities” representing indebtedness (e.g., bank borrowings, if applicable) when calculating the Fund’s asset coverage ratio or (ii) treat all such transactions as Derivatives Transactions. The requirements of Rule 18f-4 may limit the Fund’s ability to engage in Derivatives Transactions as part of its investment strategies. These requirements may also increase the cost of the Fund’s investments and cost of doing business, which could adversely affect the value of the Fund’s investments and/or the performance of the Fund. Futures Transactions Futures and options on futures entail certain risks, including but not limited to the following: ● no assurance that futures contracts or options on futures can be offset at favorable prices; ● possible reduction of the yield of the Fund due to the use of hedging; ● possible reduction in value of both the securities hedged and the hedging instrument; ● possible lack of liquidity due to daily limits or price fluctuations; ● imperfect correlation between the contracts and the securities being hedged; and ● losses from investing in futures transactions that are potentially unlimited. The Fund’s ability to establish and close out positions in futures contracts and options thereon will be subject to the development and maintenance of liquid markets. Although the Fund generally will purchase or sell only those futures contracts and options thereon for which there appears to be a liquid market, there is no assurance that a liquid market on an exchange will exist for any particular futures contract or option thereon at any particular time. In the event no liquid market exists for a particular futures contract or option thereon in which the Fund maintains a position, it will not be possible to effect a closing transaction in that contract or to do so at a satisfactory price and the Fund would have to either make or take delivery under the futures contract or, in the case of a written option, wait to sell the underlying securities until the option expires or is exercised or, in the case of a purchased option, exercise the option. In the case of a futures contract or an option thereon which the Fund has written and which the Fund is unable to close, the Fund would be required to maintain margin deposits on the futures contract or option thereon and to make variation margin payments until the contract is closed. Successful use of futures contracts and options thereon and forward contracts by the Fund is subject to the ability of the Investment Adviser to predict correctly movements in the direction of interest and foreign currency rates. If the Investment Adviser’s expectations are not met, the Fund will be in a worse position than if a hedging strategy had not been pursued. For example, if the Fund has hedged against the possibility of an increase in interest rates that would adversely affect the price of securities in its portfolio and the price of such securities increases instead, the Fund will lose part or all of the benefit of the increased value of its securities because it will have offsetting losses in its futures positions. In addition, in such situations, if the Fund has insufficient cash to meet daily variation margin requirements, it may have to sell securities to meet the requirements. These sales may be, but will not necessarily be, at increased prices that reflect the rising market. The Fund may have to sell securities at a time when it is disadvantageous to do so. Swap Agreements Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Whether the Fund’s use of swap agreements will be successful in furthering its investment objective will depend on the Investment Adviser’s ability to correctly predict whether certain types of investments are likely to produce greater returns than other investments. Because they are two party contracts and because they may have terms of greater than seven days, some swap agreements may be considered by the Fund to be illiquid. Restrictions imposed by the tax rules applicable to regulated investment companies may limit the Fund’s ability to use swap agreements. The swap market currently is largely unregulated. It is possible that developments in the swap market, including potential significant government regulation as a result of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (the “Dodd-Frank Act”) or otherwise, could adversely affect the Fund’s ability to enter into or terminate swap agreements or to realize amounts to be received under these agreements. Swap transactions may involve substantial leverage. Forward Currency Exchange Contracts The use of forward currency exchange contracts may involve certain risks, including the failure of the counterparty to perform its obligations under the contract and that the use of forward contracts may not serve as a complete hedge because of an imperfect correlation between movements in the prices of the contracts and the prices of the currencies hedged or used for cover. Dependence on Key Personnel Mr. Mario J. Gabelli is a portfolio manager of the Fund. The Investment Adviser is dependent upon the expertise of Mr. Gabelli in providing advisory services with respect to the Fund’s investments. If the Investment Adviser were to lose the services of Mr. Gabelli, its ability to service the Fund could be adversely affected. There can be no assurance that a suitable replacement could be found for Mr. Gabelli in the event of his death, resignation, retirement or inability to act on behalf of the Investment Adviser. Coronavirus (“COVID-19”) and Global Health Event Risk An outbreak of a highly contagious novel coronavirus known as “COVID 19” that was first declared in December 2019 developed into a global pandemic that had a devastating impact on the global economy, including the U.S. economy, and resulted in a global economic recession. Many states issued orders requiring the closure of non essential businesses and/or requiring residents to stay at home. The COVID 19 pandemic and preventative measures taken to contain or mitigate its spread caused business shutdowns, cancellations of events and travel, significant reductions in demand for certain goods and services, reductions in business activity and financial transactions, supply chain interruptions and overall economic and financial market instability both globally and in the United States. The U.S. economy and most other major global economies may continue to experience a substantial economic downturn or recession, and our business and operations, as well as the business and operations of our portfolio companies, could be materially adversely affected by a prolonged economic downturn or recession in the United States and other major markets. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time. These events could have a significant impact on the Fund’s performance, NAV, income, operating results and ability to pay distributions, as well as the performance, income, operating results and viability of issuers in which it invests. Market Disruption and Geopolitica
Effects of Leverage [Text Block]									Effects of Leverage The following information is furnished in response to requirements of the SEC. It is designed to, among other things, illustrate the effects of leverage through the use of senior securities, as that term is defined under Section 18 of the 1940 Act, on Common Share total return, assuming investment portfolio total returns (consisting of income and changes in the value of investments held in a Fund’s portfolio) of -10%, -5%, 0%, 5% and 10%. The table below reflects the Fund’s continued use of preferred shares and notes, as of December 31, 2023 as a percentage of total managed assets (including assets attributable to such leverage), the estimated annual effective preferred shares dividend rate and interest expense rate payable by the Fund on notes (based on market conditions as of December 31, 2023), and the annual return that the Fund’s portfolio must experience (net of expenses) in order to cover such costs. The information below does not reflect the Fund’s use of certain other forms of economic leverage achieved through the use of other instruments or transactions not considered to be senior securities under the 1940 Act, such as derivative instruments. The assumed investment portfolio returns in the table below are hypothetical figures and are not necessarily indicative of the investment portfolio returns experienced or expected to be experienced by the Fund. Your actual returns may be greater or less than those appearing below. Preferred Shares and Principal Value of Notes as a Percentage of Total Managed Assets (Including Assets Attributable to Preferred Shares and Notes) 24 % Estimated Annual Effective Preferred Share Dividend and Interest on Note Rate 5.34 % Annual Return Fund Portfolio Must Experience (net of expenses) to Cover Estimated Annual Effective Preferred Share Dividend and Interest on Note Rate 1.31 % Common Share Total Return for (10.00)% Assumed Portfolio Total Return (15.18 )% Common Share Total Return for (5.00)% Assumed Portfolio Total Return (8.60 )% Common Share Total Return for 0.00% Assumed Portfolio Total Return (2.02 )% Common Share Total Return for 5.00% Assumed Portfolio Total Return 4.56 % Common Share Total Return for 10.00% Assumed Portfolio Total Return 11.15 % Common shares total return is composed of two elements — the distributions paid by a Fund to holders of common shares (the amount of which is largely determined by the net investment income of the Fund after paying dividend payments on any preferred shares issued by the Fund and expenses on any forms of leverage outstanding, such as notes) and gains or losses on the value of the securities and other instruments the Fund owns. As required by SEC rules, the table assumes that a Fund is more likely to suffer capital losses than to enjoy capital appreciation. For example, to assume a total return of 0%, a Fund must assume that the income it receives on its investments is entirely offset by losses in the value of those investments. This table reflects hypothetical performance of the Fund’s portfolio and not the actual performance of the Fund’s common shares, the value of which is determined by market forces and other factors. Should the Fund elect to add additional leverage to its portfolio, any benefits of such additional leverage cannot be fully achieved until the proceeds resulting from the use of such leverage have been received by the Fund and invested in accordance with the Fund’s investment objectives and policies. As noted above, the Fund’s willingness to use additional leverage, and the extent to which leverage is used at any time, will depend on many factors, including, among other things, the Fund’s assessment of the yield curve environment, interest rate trends, market conditions and other factors.
Share Price [Table Text Block]									Share Price Data Common Share Corresponding Corresponding Quarter Ended High Low High Low High Low March 31, 2022 $8.34 $6.90 $4.25 $4.09 96.24% 68.70% June 30, 2022 $7.35 $6.41 $4.33 $3.74 69.75% 71.39% September 30, 2022 $7.98 $6.57 $4.08 $3.58 95.59% 83.52% December 31, 2022 $7.48 $6.68 $3.71 $3.35 101.62% 99.40% March 31, 2023 $7.81 $6.76 $3.74 $3.47 108.82% 94.81% June 30, 2023 $7.34 $6.62 $3.59 $3.21 104.46% 106.23% September 30, 2023 $7.08 $5.24 $3.28 $2.82 115.85% 85.82% December 31, 2023 $6.26 $4.84 $2.96 $2.70 111.49% 79.26%
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Capital Stock [Table Text Block]									6. Capital. Transactions in shares of beneficial interest were as follows: Year Ended Year Ended December 31, December 31, Shares Amount Shares Amount Net increase in net assets from common shares issued in rights offering — — 9,133,529 $ 50,234,410 Net increase in net assets from common shares issued upon reinvestment of distributions 1,199,062 $ 7,571,314 1,011,565 6,983,503 Net increase 1,199,062 $ 7,571,314 10,145,094 $ 57,217,913 The Fund’s Declaration of Trust, as amended, authorizes the issuance of an unlimited number of shares of $0.001 par value Preferred Shares. The Preferred Shares are senior to the common shares and result in the financial leveraging of the common shares. Such leveraging tends to magnify both the risks and opportunities to common shareholders. Dividends on the Preferred Shares are cumulative. The Fund is required by the 1940 Act and by the Statement of Additional Information to meet certain asset coverage tests with respect to the Preferred Shares. If the Fund fails to meet these requirements and does not correct such failure, the Fund may be required to redeem, in part or in full, Series B and Series C Preferred Shares at redemption prices of $25,000 and $25, respectively, per share plus an amount equal to the accumulated and unpaid dividends whether or not declared on such shares in order to meet these requirements. Additionally, failure to meet the foregoing asset coverage requirements could restrict the Fund’s ability to pay dividends to common shareholders and could lead to sales of portfolio securities at inopportune times. The income received on the Fund’s assets may vary in a manner unrelated to the fixed and variable rates, which could have either a beneficial or detrimental impact on investment income and gains available to common shareholders. The Fund may redeem at any time, in whole or in part, the Series B Preferred and Series C Preferred at their respective liquidation preferences of $25,000 and $25. In addition, the Board has authorized the repurchase of the Series C Preferred in the open market at prices less than the $25 liquidation value per share. During the years ended December 31, 2023 and 2022, the Fund repurchased and retired 13,876 and 12,774 shares of the Series C Preferred Shares in the open market at an investment of $313,603 and $303,012 and at average discounts of approximately 9.6% and 5.2%, respectively, from its liquidation preference; during the year ended December 31, 2022, the Fund did not repurchase any shares of Series B Preferred. On October 16, 2023, the Fund completed an exchange offer (the Offer) under which owners of the Series B Preferred could exchange their Series B Preferred for newly issued promissory notes (the Notes) at the exchange ratio of $912 per $1,000 of liquidation preference of Series B Preferred validly tendered and not withdrawn pursuant to the Offer, and issued $20,477,094 principal amount of Note for the 898 Series B Preferred validly tendered and not withdrawn. The Notes bear an annual interest rate of 5.25%, and interest is paid monthly. The aggregate unpaid principal amount of the Notes, all accrued and unpaid interest, and all other amounts payable under the terms of the Notes will be due and payable on December 31, 2024. The carrying value of the Note Payable approximates fair value. The Note Payable is classified as Level 2 in the fair value hierarchy. On January 31, 2022, the Fund redeemed all Series A Preferred at the Redemption Price of $25.13671875 per share, which consisted of the liquidation preference of $25.00 plus $0.13671875 per share representing accumulated but unpaid dividends and distributions to the redemption date of January 31, 2022. For Series B Preferred Shares, the dividend rates are typically set by an auction process that is generally held every seven days, and are typically expected to vary with short term interest rates. Since February 2008, the number of Series B Preferred Shares subject to bid orders by potential holders has been less than the number of shares of Series B sell orders. Holders that have submitted sell orders have not been able to sell any or all of the Series B Preferred Shares for which they have submitted sell orders. Therefore the weekly auctions that failed resulted in the dividend rate being the maximum rate. The current maximum rate for Series B Preferred Shares is 200 basis points greater than the seven day ICE LIBOR rate on the date of such auction. Since December 31, 2021, the seven day ICE LIBOR rate has ceased to be published and is no longer representative. Because the Series B Preferred Shares have no other effective alternative rate setting provision, a last resort fallback of fixing this LIBOR based reference rate at its last published rate applies. The last published seven day ICE LIBOR rate was 0.076%, which results in a maximum rate for Series B Preferred Shares of 2.076% for all failed auctions after December 31, 2021. In the absence of successful future auctions that establish dividend rates based on prevailing short term interest rates, this result could lead to divergent and unexpected economic results for the Fund and holders of the Series B Preferred Shares since the rates payable on the Series B Preferred Shares are no longer likely to be representative of prevailing market rates. Existing Series B Preferred shareholders may submit an order to hold, bid, or sell such shares on each auction date, or trade their shares in the secondary market. The Fund has the authority to purchase its Series B auction market preferred shares through negotiated private transactions. The Fund is not obligated to purchase any dollar amount or number of auction market preferred shares, and the timing and amount of any auction market preferred shares purchased will depend on market conditions, share price, capital availability, and other factors. The Fund is not soliciting holders to sell these shares nor recommending that holders offer them to the Fund. Any offers can be accepted or rejected in the Fund’s discretion. The following table summarizes Cumulative Preferred Shares information: Series Issue Date Authorized Number of Net 2023 Dividend Dividend Accrued B Auction Market July 31, 2003 1,000 2 $ 24,590,026 0.069% to 2.076% 0.069 % $ 0 C 5.375% May 31, 2016 2,000,000 1,973,350 $ 48,142,029 Fixed Rate 5.375 % $ 36,829 The holders of Preferred Shares generally are entitled to one vote per share held on each matter submitted to a vote of shareholders of the Fund and will vote together with holders of common stock as a single class. The holders of Preferred Shares voting together as a single class also have the right currently to elect two Trustees and under certain circumstances are entitled to elect a majority of the Board of Trustees. In addition, the affirmative vote of a majority of the votes entitled to be cast by holders of all outstanding shares of the preferred shares, voting as a single class, will be required to approve any plan of reorganization adversely affecting the preferred shares, and the approval of two-thirds of each class, voting separately, of the Fund’s outstanding voting stock must approve the conversion of the Fund from a closed-end to an open-end investment company. The approval of a majority (as defined in the 1940 Act) of the outstanding preferred shares and a majority (as defined in the 1940 Act) of the Fund’s outstanding voting securities are required to approve certain other actions, including changes in the Fund’s investment objectives or fundamental investment policies. On March 10, 2022, the Fund distributed one transferable right for each of the 63,934,698 common shares outstanding on that date. Seven rights were required to purchase one additional common share at the subscription price of $5.50 per share. On April 20, 2022, the Fund issued 9,133,529 common shares receiving net proceeds of $49,849,194, after the deduction of offering expenses of $385,216. The NAV of the Fund increased by $0.16 per share on the day the additional shares were issued due to the additional shares being issued above NAV. The Fund has an effective shelf registration authorizing an additional $300 million of common or preferred shares.
Document Period End Date									Dec. 31, 2023
Common Stocks [Member]
General Description of Registrant [Abstract]
Return at Minus Ten [Percent]									(15.18%)
Return at Minus Five [Percent]									(8.60%)
Return at Zero [Percent]									(2.02%)
Return at Plus Five [Percent]									4.56%
Return at Plus Ten [Percent]									11.15%
Lowest Price or Bid	$ 4.84	$ 5.24	$ 6.62	$ 6.76	$ 6.68	$ 6.57	$ 6.41	$ 6.90
Highest Price or Bid	6.26	7.08	7.34	7.81	7.48	7.98	7.35	8.34
Lowest Price or Bid, NAV	2.70	2.82	3.21	3.47	3.35	3.58	3.74	4.09
Highest Price or Bid, NAV	$ 2.96	$ 3.28	$ 3.59	$ 3.74	$ 3.71	$ 4.08	$ 4.33	$ 4.25
Highest Price or Bid, Premium (Discount) to NAV [Percent]	111.49%	115.85%	104.46%	108.82%	101.62%	95.59%	69.75%	96.24%
Lowest Price or Bid, Premium (Discount) to NAV [Percent]	79.26%	85.82%	106.23%	94.81%	99.40%	83.52%	71.39%	68.70%
NAV Per Share	$ 2.94								$ 2.94
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Outstanding Security, Not Held [Shares]									75,142,210
Series A Cumulative Preferred Stock [Member]
Financial Highlights [Abstract]
Senior Securities Amount											$ 28,832,000	$ 28,832,000	$ 28,832,000	$ 28,832
Senior Securities Coverage per Unit											$ 93.41	$ 80.82	$ 92.43	$ 85.97	$ 82.94	$ 83.35	$ 131.74	$ 151.49
Preferred Stock Liquidating Preference											25	25	25	25	25	25	25	25
Senior Securities Average Market Value per Unit											$ 26.93	$ 26.78	$ 26.19	$ 25.43	$ 25.68	$ 25.88	$ 25.55	$ 25.14
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Outstanding Security, Not Held [Shares]											1,153,000	1,153,000	1,153,000	1,153,000	1,153,000	1,153,000	1,153,000	1,153,000
Series B Cumulative Preferred Stock [Member]
Financial Highlights [Abstract]
Senior Securities Amount	$ 50,000				$ 22,500,000				$ 50,000	$ 22,500,000	$ 22,500,000	$ 22,500,000	$ 22,500,000	$ 22,500	$ 22,500	$ 22,500	$ 22,500	$ 22,500
Senior Securities Coverage per Unit	$ 103,983				$ 118,589				$ 103,983	$ 118,589	$ 93,413	$ 80,821	$ 92,425	$ 85,967	$ 82,936	$ 83,347	$ 131,744	$ 151,486
Preferred Stock Liquidating Preference	$ 25,000				$ 25,000				25,000	25,000	25,000	25,000	25,000	25,000	25,000	25,000	25,000	25,000
Senior Securities Average Market Value per Unit									$ 25,000	$ 25,000	$ 25,000	$ 25,000	$ 25,000	$ 25,000	$ 25,000	$ 25,000	$ 25,000	$ 25,000
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Outstanding Security, Title [Text Block]									B Auction Market
Outstanding Security, Authorized [Shares]									1,000
Outstanding Security, Held [Shares]									2
Outstanding Security, Not Held [Shares]									0	1,000	1,000	1,000	1,000	1,000	1,000	1,000	1,000	1,000
Series C Cumulative Preferred Stock [Member]
Financial Highlights [Abstract]
Senior Securities Amount	$ 49,334,000				$ 49,681,000				$ 49,334,000	$ 49,681,000	$ 50,000,000	$ 50,000,000	$ 50,000,000	$ 50,000,000	$ 50,000,000	$ 50,000,000
Senior Securities Coverage per Unit	$ 103.98				$ 118.59				$ 103.98	$ 118.59	$ 93.41	$ 80.82	$ 92.43	$ 85.97	$ 82.94	$ 83.35
Preferred Stock Liquidating Preference	$ 25				$ 25				25	25	25	25	25	25	25	25
Senior Securities Average Market Value per Unit									$ 23.99	$ 25	$ 26.02	$ 25.96	$ 25.90	$ 25.01	$ 25.32	$ 25.28
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Outstanding Security, Title [Text Block]									C 5.375%
Outstanding Security, Authorized [Shares]									2,000,000
Outstanding Security, Held [Shares]									1,973,350
Outstanding Security, Not Held [Shares]									1,973,000	1,987,000	2,000,000	2,000,000	2,000,000	2,000,000	2,000,000	2,000,000
Cumulative Preferred Stocks [Member]
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Security Voting Rights [Text Block]									The holders of Preferred Shares generally are entitled to one vote per share held on each matter submitted to a vote of shareholders of the Fund and will vote together with holders of common stock as a single class. The holders of Preferred Shares voting together as a single class also have the right currently to elect two Trustees and under certain circumstances are entitled to elect a majority of the Board of Trustees. In addition, the affirmative vote of a majority of the votes entitled to be cast by holders of all outstanding shares of the preferred shares, voting as a single class, will be required to approve any plan of reorganization adversely affecting the preferred shares, and the approval of two-thirds of each class, voting separately, of the Fund’s outstanding voting stock must approve the conversion of the Fund from a closed-end to an open-end investment company. The approval of a majority (as defined in the 1940 Act) of the outstanding preferred shares and a majority (as defined in the 1940 Act) of the Fund’s outstanding voting securities are required to approve certain other actions, including changes in the Fund’s investment objectives or fundamental investment policies. On March 10, 2022, the Fund distributed one transferable right for each of the 63,934,698 common shares outstanding on that date. Seven rights were required to purchase one additional common share at the subscription price of $5.50 per share. On April 20, 2022, the Fund issued 9,133,529 common shares receiving net proceeds of $49,849,194, after the deduction of offering expenses of $385,216. The NAV of the Fund increased by $0.16 per share on the day the additional shares were issued due to the additional shares being issued above NAV. The Fund has an effective shelf registration authorizing an additional $300 million of common or preferred shares.
Preferred Stock Restrictions, Other [Text Block]									The Fund’s Declaration of Trust, as amended, authorizes the issuance of an unlimited number of shares of $0.001 par value Preferred Shares. The Preferred Shares are senior to the common shares and result in the financial leveraging of the common shares. Such leveraging tends to magnify both the risks and opportunities to common shareholders. Dividends on the Preferred Shares are cumulative. The Fund is required by the 1940 Act and by the Statement of Additional Information to meet certain asset coverage tests with respect to the Preferred Shares. If the Fund fails to meet these requirements and does not correct such failure, the Fund may be required to redeem, in part or in full, Series B and Series C Preferred Shares at redemption prices of $25,000 and $25, respectively, per share plus an amount equal to the accumulated and unpaid dividends whether or not declared on such shares in order to meet these requirements. Additionally, failure to meet the foregoing asset coverage requirements could restrict the Fund’s ability to pay dividends to common shareholders and could lead to sales of portfolio securities at inopportune times. The income received on the Fund’s assets may vary in a manner unrelated to the fixed and variable rates, which could have either a beneficial or detrimental impact on investment income and gains available to common shareholders. The Fund may redeem at any time, in whole or in part, the Series B Preferred and Series C Preferred at their respective liquidation preferences of $25,000 and $25. In addition, the Board has authorized the repurchase of the Series C Preferred in the open market at prices less than the $25 liquidation value per share. During the years ended December 31, 2023 and 2022, the Fund repurchased and retired 13,876 and 12,774 shares of the Series C Preferred Shares in the open market at an investment of $313,603 and $303,012 and at average discounts of approximately 9.6% and 5.2%, respectively, from its liquidation preference; during the year ended December 31, 2022, the Fund did not repurchase any shares of Series B Preferred. On October 16, 2023, the Fund completed an exchange offer (the Offer) under which owners of the Series B Preferred could exchange their Series B Preferred for newly issued promissory notes (the Notes) at the exchange ratio of $912 per $1,000 of liquidation preference of Series B Preferred validly tendered and not withdrawn pursuant to the Offer, and issued $20,477,094 principal amount of Note for the 898 Series B Preferred validly tendered and not withdrawn. The Notes bear an annual interest rate of 5.25%, and interest is paid monthly. The aggregate unpaid principal amount of the Notes, all accrued and unpaid interest, and all other amounts payable under the terms of the Notes will be due and payable on December 31, 2024. The carrying value of the Note Payable approximates fair value. The Note Payable is classified as Level 2 in the fair value hierarchy. On January 31, 2022, the Fund redeemed all Series A Preferred at the Redemption Price of $25.13671875 per share, which consisted of the liquidation preference of $25.00 plus $0.13671875 per share representing accumulated but unpaid dividends and distributions to the redemption date of January 31, 2022. For Series B Preferred Shares, the dividend rates are typically set by an auction process that is generally held every seven days, and are typically expected to vary with short term interest rates. Since February 2008, the number of Series B Preferred Shares subject to bid orders by potential holders has been less than the number of shares of Series B sell orders. Holders that have submitted sell orders have not been able to sell any or all of the Series B Preferred Shares for which they have submitted sell orders. Therefore the weekly auctions that failed resulted in the dividend rate being the maximum rate. The current maximum rate for Series B Preferred Shares is 200 basis points greater than the seven day ICE LIBOR rate on the date of such auction. Since December 31, 2021, the seven day ICE LIBOR rate has ceased to be published and is no longer representative. Because the Series B Preferred Shares have no other effective alternative rate setting provision, a last resort fallback of fixing this LIBOR based reference rate at its last published rate applies. The last published seven day ICE LIBOR rate was 0.076%, which results in a maximum rate for Series B Preferred Shares of 2.076% for all failed auctions after December 31, 2021. In the absence of successful future auctions that establish dividend rates based on prevailing short term interest rates, this result could lead to divergent and unexpected economic results for the Fund and holders of the Series B Preferred Shares since the rates payable on the Series B Preferred Shares are no longer likely to be representative of prevailing market rates. Existing Series B Preferred shareholders may submit an order to hold, bid, or sell such shares on each auction date, or trade their shares in the secondary market. The Fund has the authority to purchase its Series B auction market preferred shares through negotiated private transactions. The Fund is not obligated to purchase any dollar amount or number of auction market preferred shares, and the timing and amount of any auction market preferred shares purchased will depend on market conditions, share price, capital availability, and other factors. The Fund is not soliciting holders to sell these shares nor recommending that holders offer them to the Fund. Any offers can be accepted or rejected in the Fund’s discretion.
Outstanding Securities [Table Text Block]									The following table summarizes Cumulative Preferred Shares information: Series Issue Date Authorized Number of Net 2023 Dividend Dividend Accrued B Auction Market July 31, 2003 1,000 2 $ 24,590,026 0.069% to 2.076% 0.069 % $ 0 C 5.375% May 31, 2016 2,000,000 1,973,350 $ 48,142,029 Fixed Rate 5.375 % $ 36,829
Utility Industry Risks [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Utility Industry Risks Under normal market conditions, the Fund will invest at least 80% of its net assets (plus borrowings made for investment purposes) in foreign and domestic companies involved in the Utility Industry and, as a result, the value of the common shares will be more susceptible to factors affecting those particular types of companies, including governmental regulation, inflation, cost increases in fuel and other operating expenses, technological innovations that may render existing products and equipment obsolete and increasing interest rates resulting in high interest costs on borrowings needed for capital construction programs, including costs associated with compliance with environmental and other regulations.
Sector Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Sector Risk.
Government Regulation [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Government Regulation. any given regulatory agency may make major shifts in policy from time to time. There is no assurance that regulatory authorities will, in the future, permit companies to implement rate increases or that such increases will be adequate to permit the payment of dividends on such issuer’s common shares. Additionally, existing and possible future regulatory legislation may make it even more difficult for companies in the Utility Industry to obtain adequate relief from rate regulation. Regulatory considerations limit the percentage of the shares of a public utility held by a fund or by an adviser and its affiliates on behalf of all their clients. Various types of ownership restrictions are imposed by the Federal Communications Commission (“FCC”) on investment in media companies and cellular licensees. These rules limit the number of broadcast stations both locally and nationally that a single entity is permitted to own, operate, or control and prohibit ownership of certain competitive communications providers in the same location. The FCC also applies limited ownership restrictions on cellular licensees serving rural areas. Attributable interests that may result from the role of the Investment Adviser and its principals in connection with other funds, managed accounts and companies may limit the Fund’s ability to invest in certain mass media and cellular companies. These limitations may unfavorably restrict the ability of the Fund to make certain investments.
Deregulation [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Deregulation.
Financing [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Financing.
Equipment And Supplies [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Equipment and Supplies. availability of fuel (such as oil, coal, nuclear or natural gas) also may adversely affect the profitability of utility companies. Electric utilities may be burdened by unexpected increases in operating costs. They may also be negatively affected when long term interest rates rise. Long term borrowings are used to finance most utility investments, and rising interest rates lead to higher financing costs and reduced earnings. There are also the considerable costs associated with environmental compliance, nuclear waste clean-up, cap and trade or other programs designed to reduce carbon dioxide and other greenhouse emissions, and safety regulation. Increasingly, regulators are calling upon electric utilities to bear these added costs, and there is a risk that these costs will not be fully recovered through an increase in revenues. Among gas companies, there has been a move to diversify into oil and gas exploration and development, making investment returns more sensitive to energy prices. In the case of the water utility sector, the industry is highly fragmented, and most water supply companies find themselves in mature markets, although upgrading of fresh water and waste water systems is an expanding business.
Long Term Objective Not A Complete Investment Program [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Long Term Objective: Not a Complete Investment Program The Fund is intended for investors seeking long term capital growth and income. The Fund is not meant to provide a vehicle for those who wish to exploit short term swings in the stock market. An investment in shares of the Fund should not be considered a complete investment program. Each shareholder should take into account the Fund’s investment objective as well as the shareholder’s other investments when considering an investment in the Fund.
Market Value And Net Asset Value [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Market Value and Net Asset Value The Fund is a diversified, closed-end management investment company. Shares of closed-end funds are bought and sold in the securities markets and may trade at either a premium to or discount from NAV. Listed shares of closed-end investment companies often trade at discounts from NAV. This characteristic of shares of a closed-end fund is a risk separate and distinct from the risk that its NAV may decrease. The Fund cannot predict whether its listed shares will trade at, below or above NAV. The risk of holding shares of a closed-end fund that might trade at a discount is more pronounced for shareholders who wish to sell their shares in a relatively short period of time after acquiring them because, for those investors, realization of a gain or loss on their investments is likely to be more dependent upon the existence of a premium or discount than upon portfolio performance. The Fund’s shares are not subject to redemption. Shortly after the inception of the Fund, the market price of the Fund exceeded the NAV and the premium continues today. Shareholders desiring liquidity may, subject to applicable securities laws, trade their Fund shares on the New York Stock Exchange (“NYSE”) or other markets on which such shares may trade at the then-current market value, which may differ from the then-current NAV. Shareholders will incur brokerage or other transaction costs to sell shares.
Non Investment Grade Securities [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Non-Investment Grade Securities The Fund may invest up to 25% of its total assets in fixed income securities rated below investment grade by recognized statistical rating agencies or unrated securities of comparable quality. These securities, which may be preferred stock or debt, are predominantly speculative and involve major risk exposure to adverse conditions. Debt securities that are not rated or that are rated lower than “BBB” by S&P or lower than “Baa” by Moody’s are referred to in the financial press as “junk bonds.” Such securities are subject to greater risks than investment grade securities, which reflect their speculative character, including the following: ● greater volatility; ● greater credit risk; ● potentially greater sensitivity to general economic or industry conditions; ● potential lack of attractive resale opportunities (illiquidity); and ● additional expenses to seek recovery from issuers who default. Fixed income securities purchased by the Fund may be rated as low as C by Moody’s or D by S&P or may be unrated securities considered to be of equivalent quality. Securities that are rated C by Moody’s are the lowest rated class and can be regarded as having extremely poor prospects of ever obtaining investment-grade standing. Debt rated D by S&P is in default or is expected to default upon maturity of payment date. The market value of non-investment grade securities may be more volatile than the market value of higher rated securities and generally tends to reflect the market’s perception of the creditworthiness of the issuer and short term market developments to a greater extent than more highly rated securities, which primarily reflect fluctuations in general levels of interest rates. Generally, such non-investment grade securities and unrated securities of comparable quality offer a higher current yield than is offered by higher rated securities, but also (i) will likely have some quality and protective characteristics that, in the judgment of the rating organizations, are outweighed by large uncertainties or major risk exposures to adverse conditions and (ii) are predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal in accordance with the terms of the obligation. The market values of certain of these securities also tend to be more sensitive to individual corporate developments and changes in economic conditions than higher quality securities. In addition, such securities generally present a higher degree of credit risk. The risk of loss due to default by these issuers is significantly greater because such non-investment grade securities and unrated securities of comparable quality generally are unsecured and frequently are subordinated to the prior payment of senior indebtedness. In light of these risks, the Investment Adviser, in evaluating the creditworthiness of an issue, whether rated or unrated, will take various factors into consideration, which may include, as applicable, the issuer’s operating history, financial resources and its sensitivity to economic conditions and trends, the market support for the facility financed by the issue, the perceived ability and integrity of the issuer’s management, and regulatory matters. Non-investment grade securities also present risks based on payment expectations. If an issuer calls the obligation for redemption (often a feature of fixed income securities), the Fund may have to replace the security with a lower yielding security, resulting in a decreased return for investors. Also, as the principal value of nonconvertible bonds and preferred stocks moves inversely with movements in interest rates, in the event of rising interest rates the value of the securities held by the Fund may decline proportionately more than a portfolio consisting of higher rated securities. Investments in zero coupon bonds may be more speculative and subject to greater fluctuations in value due to changes in interest rates than bonds that pay regular income streams. Ratings are relative and subjective, and are not absolute standards of quality. Securities ratings are based largely on the issuer’s historical financial condition and the rating agencies’ analysis at the time of rating. Consequently, the rating assigned to any particular security is not necessarily a reflection of the issuer’s current financial condition. As part of its investment in non-investment grade securities, the Fund may invest in securities of issuers in default. The Fund will make an investment in securities of issuers in default only when the Investment Adviser believes that such issuers will honor their obligations or emerge from bankruptcy protection under a plan pursuant to which the securities received by the Fund in exchange for its defaulted securities will have a value in excess of the Fund’s investment. By investing in securities of issuers in default, the Fund bears the risk that these issuers will not continue to honor their obligations or emerge from bankruptcy protection or that the value of the securities will not otherwise appreciate.
Equity Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Equity Risk Investing in the Fund involves equity risk, which is the risk that the securities held by the Fund will fall in market value due to adverse market and economic conditions, perceptions regarding the industries in which the issuers of securities held by the Fund participate and the particular circumstances and performance of particular companies whose securities the Fund holds. An investment in the Fund represents an indirect economic stake in the securities owned by the Fund, which are for the most part traded on securities exchanges or in the OTC markets. The market value of these securities, like other market investments, may move up or down, sometimes rapidly and unpredictably. The NAV of the Fund may at any point in time be worth less than the amount at the time the shareholder invested in the Fund, even after taking into account any reinvestment of distributions.
Foreign Securities [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Foreign Securities The Fund may invest its assets in foreign securities without limitation, including securities of issuers whose primary operations or principal trading market is in an “emerging market.” Investments in the securities of foreign issuers involve certain considerations and risks not ordinarily associated with investments in securities of domestic issuers and such securities may be more volatile than those of issuers in the United States. Foreign companies are not generally subject to uniform accounting, auditing and financial standards and requirements comparable to those applicable to United States companies. Foreign securities exchanges, brokers and listed companies may be subject to less government supervision and regulation than exists in the United States. Dividend and interest income may be subject to withholding and other foreign taxes, which may adversely affect the net return on such investments. There may be difficulty in obtaining or enforcing a court judgment abroad. In addition, it may be difficult to effect repatriation of capital invested in certain countries. Also, with respect to certain countries, there are risks of expropriation, confiscatory taxation, political or social instability or diplomatic developments that could affect assets of the Fund held in foreign countries. Dividend income that the Fund receives from foreign securities may not be eligible for the special tax treatment applicable to qualified dividend income. Moreover, certain equity investments in foreign issuers classified as passive foreign investment companies may be subject to additional taxation risk. There may be less publicly available information about a foreign company than a United States company. Foreign securities markets may have substantially less volume than United States securities markets and some foreign company securities are less liquid than securities of otherwise comparable United States companies. A portfolio of foreign securities may also be adversely affected by fluctuations in the rates of exchange between the currencies of different nations and by exchange control regulations. Foreign markets also have different clearance and settlement procedures that could cause the Fund to encounter difficulties in purchasing and selling securities on such markets and may result in the Fund missing attractive investment opportunities or experiencing loss. In addition, a portfolio that includes foreign securities can expect to have a higher expense ratio because of the increased transaction costs on non-United States securities markets and the increased costs of maintaining the custody of foreign securities. The Fund also may purchase sponsored American Depositary Receipts (“ADRs”) or United States dollar denominated securities of foreign issuers. ADRs are receipts issued by United States banks or trust companies in respect of securities of foreign issuers held on deposit for use in the United States securities markets. While ADRs may not necessarily be denominated in the same currency as the securities into which they may be converted, many of the risks associated with foreign securities may also apply to ADRs. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts, or to pass through to them any voting rights with respect to the deposited securities.
Emerging Markets [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Emerging Markets An “emerging market” country is any country that is considered to be an emerging or developing country by the International Bank for Reconstruction and Development. Investing in securities of companies in emerging markets may entail special risks relating to potential political and economic instability and the risks of expropriation, nationalization, confiscation or the imposition of restrictions on foreign investment, the lack of hedging instruments and restrictions on repatriation of capital invested. Emerging securities markets are substantially smaller, less developed, less liquid and more volatile than the major securities markets. The limited size of emerging securities markets and limited trading value compared to the volume of trading in U.S. securities could cause prices to be erratic for reasons apart from factors that affect the quality of the securities. For example, limited market size may cause prices to be unduly influenced by traders who control large positions. Adverse publicity and investors’ perceptions, whether or not based on fundamental analysis, may decrease the value and liquidity of portfolio securities, especially in these markets. Other risks include high concentration of market capitalization and trading volume in a small number of issuers representing a limited number of industries, as well as a high concentration of investors and financial intermediaries; overdependence on exports, including gold and natural resources exports, making these economies vulnerable to changes in commodity prices; overburdened infrastructure and obsolete or unseasoned financial systems; environmental problems; potential for sanctions; less developed legal systems, and deficiencies in regulatory oversight, market infrastructure, shareholder protections; differences in regulatory, accounting, auditing and financial reporting and recordkeeping standards; and less reliable securities custodial services and settlement practices.
Small And Mid Cap Stock Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Small- and Mid-Cap Stock Risk The Fund may invest in companies with small or medium capitalizations. Smaller and medium company stocks can be more volatile than, and perform differently from, larger company stocks. There may be less trading in a smaller or medium company’s stock, which means that buy and sell transactions in that stock could have a larger impact on the stock’s price than is the case with larger company stocks. Smaller and medium company stocks may be particularly sensitive to changes in interest rates, borrowing costs and earnings. Smaller and medium companies may have fewer business lines; changes in any one line of business, therefore, may have a greater impact on a smaller and medium company’s stock price than is the case for a larger company. As a result, the purchase or sale of more than a limited number of shares of a small and medium company may affect its market price. The Fund may need a considerable amount of time to purchase or sell its positions in these securities. In addition, smaller or medium company stocks may not be well known to the investing public.
Special Risks Of Derivative Transactions [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Special Risks of Derivative Transactions The Fund may participate in derivative transactions. Such transactions entail certain execution, market, liquidity, hedging and tax risks. Participation in the options, futures or swaps markets and in currency exchange transactions involves investment risks and transaction costs to which the Fund would not be subject absent the use of these strategies. If the Investment Adviser’s prediction of movements in the direction of the securities, foreign currency and interest rate markets are inaccurate, the consequences to the Fund may leave the Fund in a worse position than if such strategies were not used. Risks inherent in the use of options, foreign currency, swaps contracts, futures contracts and options on futures contracts, swap contracts, securities indices and foreign currencies include: ● dependence on the Investment Adviser’s ability to predict correctly movements in the direction of interest rates, securities prices and currency markets; ● imperfect correlation between the price of options and futures contracts and options thereon and move-ments in the prices of the securities or currencies being hedged; ● the fact that skills needed to use these strategies are different from those needed to select portfolio securities; ● the possible absence of a liquid secondary market for any particular instrument at any time; ● the possible need to defer closing out certain hedged positions to avoid adverse tax consequences; ● the possible inability of the Fund to purchase or sell a security at a time that otherwise would be favorable for it to do so; and ● the creditworthiness of counterparties. Options, futures contracts, swaps contracts, and options thereon and forward contracts on securities and currencies may be traded on foreign exchanges. Such transactions may not be regulated as effectively as similar transactions in the United States, may not involve a clearing mechanism and related guarantees, and are subject to the risk of governmental actions affecting trading in, or the prices of, foreign securities. The value of such positions also could be adversely affected by (i) other complex foreign political, legal and economic factors, (ii) lesser availability than in the United States of data on which to make trading decisions, (iii) delays in the ability of the Fund to act upon economic events occurring in the foreign markets during non-business hours in the United States, (iv) the imposition of different exercise and settlement terms and procedures and margin requirements than in the United States and (v) less trading volume. Exchanges on which options, futures, swaps and options on futures or swaps are traded may impose limits on the positions that the Fund may take in certain circumstances. Many OTC derivatives are valued on the basis of dealers’ pricing of these instruments. However, the price at which dealers value a particular derivative and the price which the same dealers would actually be willing to pay for such derivative should the Fund wish or be forced to sell such position may be materially different. Such differences can result in an overstatement of the Fund’s NAV and may materially adversely affect the Fund in situations in which the Fund is required to sell derivative instruments. Exchange-traded derivatives and OTC derivative transactions submitted for clearing through a central counterparty have become subject to minimum initial and variation margin requirements set by the relevant clearinghouse, as well as possible margin requirements mandated by the SEC or the Commodity Futures Trading Commission. These regulators also have broad discretion to impose margin requirements on non-cleared OTC derivatives. These margin requirements will increase the overall costs for the Fund. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. Derivatives may give rise to a form of leverage and may expose the Fund to greater risk and increase its costs. Under Rule 18f-4 under the 1940 Act, among other things, the Fund must either use derivatives in a limited manner or comply with an outer limit on fund leverage risk based on value-at-risk. See “—Derivatives Transactions Subject to Rule18f-4 Under the 1940 Act” below. Derivatives Transactions Subject to Rule 18f-4 Under the 1940 Act Under Rule 18f-4, “Derivatives Transactions” include the following: (i) any swap, security-based swap (including a contract for differences), futures contract, forward contract, option (excluding purchased options), any combination of the foregoing, or any similar instrument, under which the Fund is or may be required to make any payment or delivery of cash or other assets during the life of the instrument or at maturity or early termination, whether as margin or settlement payment or otherwise; (ii) any short sale borrowing; (iii) reverse repurchase agreements and similar financing transactions, if the Fund elects to treat these transactions as Derivatives Transactions under Rule 18f-4; and (iv) when-issued or forward-settling securities (e.g., firm and standby commitments, including to-be-announced commitments, and dollar rolls) and non-standard settlement cycle securities, unless the Fund intends to physically settle the transaction and the transaction will settle within 35 days of its trade date. Unless the Fund is relying on the Limited Derivatives User Exception (as defined below), the Fund must comply with Rule 18f-4 with respect to its Derivatives Transactions. Rule 18f-4, among other things, requires the Fund to (i) appoint a Derivatives Risk Manager; (ii) maintain a Derivatives Risk Management Program designed to identify, assess, and reasonably manage the risks associated with Derivatives Transactions; (iii) comply with certain value-at-risk (VaR)-based leverage limits (VaR is an estimate of an instrument’s or portfolio’s potential losses over a given time horizon and at a specified confidence level); and (iv) comply with certain Board reporting and recordkeeping requirements. Rule 18f-4 provides an exception from the requirements to appoint a Derivatives Risk Manager, adopt a Derivatives Risk Management Program, comply with certain VaR-based leverage limits, and comply with certain Board oversight and reporting requirements if the Fund’s “derivatives exposure” (as defined in Rule 18f-4) is limited to 10% of its net assets (as calculated in accordance with Rule 18f-4) and the Fund adopts and implements written policies and procedures reasonably designed to manage its derivatives risks (the “Limited Derivatives User Exception”). Pursuant to Rule 18f-4, if the Fund enters into reverse repurchase agreements or similar financing transactions, the Fund will (i) aggregate the amount of indebtedness associated with all of its reverse repurchase agreements or similar financing transactions with the amount of any other “senior securities” representing indebtedness (e.g., bank borrowings, if applicable) when calculating the Fund’s asset coverage ratio or (ii) treat all such transactions as Derivatives Transactions. The requirements of Rule 18f-4 may limit the Fund’s ability to engage in Derivatives Transactions as part of its investment strategies. These requirements may also increase the cost of the Fund’s investments and cost of doing business, which could adversely affect the value of the Fund’s investments and/or the performance of the Fund.
Futures Transactions [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Futures Transactions Futures and options on futures entail certain risks, including but not limited to the following: ● no assurance that futures contracts or options on futures can be offset at favorable prices; ● possible reduction of the yield of the Fund due to the use of hedging; ● possible reduction in value of both the securities hedged and the hedging instrument; ● possible lack of liquidity due to daily limits or price fluctuations; ● imperfect correlation between the contracts and the securities being hedged; and ● losses from investing in futures transactions that are potentially unlimited. The Fund’s ability to establish and close out positions in futures contracts and options thereon will be subject to the development and maintenance of liquid markets. Although the Fund generally will purchase or sell only those futures contracts and options thereon for which there appears to be a liquid market, there is no assurance that a liquid market on an exchange will exist for any particular futures contract or option thereon at any particular time. In the event no liquid market exists for a particular futures contract or option thereon in which the Fund maintains a position, it will not be possible to effect a closing transaction in that contract or to do so at a satisfactory price and the Fund would have to either make or take delivery under the futures contract or, in the case of a written option, wait to sell the underlying securities until the option expires or is exercised or, in the case of a purchased option, exercise the option. In the case of a futures contract or an option thereon which the Fund has written and which the Fund is unable to close, the Fund would be required to maintain margin deposits on the futures contract or option thereon and to make variation margin payments until the contract is closed. Successful use of futures contracts and options thereon and forward contracts by the Fund is subject to the ability of the Investment Adviser to predict correctly movements in the direction of interest and foreign currency rates. If the Investment Adviser’s expectations are not met, the Fund will be in a worse position than if a hedging strategy had not been pursued. For example, if the Fund has hedged against the possibility of an increase in interest rates that would adversely affect the price of securities in its portfolio and the price of such securities increases instead, the Fund will lose part or all of the benefit of the increased value of its securities because it will have offsetting losses in its futures positions. In addition, in such situations, if the Fund has insufficient cash to meet daily variation margin requirements, it may have to sell securities to meet the requirements. These sales may be, but will not necessarily be, at increased prices that reflect the rising market. The Fund may have to sell securities at a time when it is disadvantageous to do so.
Swap Agreements [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Swap Agreements Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Whether the Fund’s use of swap agreements will be successful in furthering its investment objective will depend on the Investment Adviser’s ability to correctly predict whether certain types of investments are likely to produce greater returns than other investments. Because they are two party contracts and because they may have terms of greater than seven days, some swap agreements may be considered by the Fund to be illiquid. Restrictions imposed by the tax rules applicable to regulated investment companies may limit the Fund’s ability to use swap agreements. The swap market currently is largely unregulated. It is possible that developments in the swap market, including potential significant government regulation as a result of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (the “Dodd-Frank Act”) or otherwise, could adversely affect the Fund’s ability to enter into or terminate swap agreements or to realize amounts to be received under these agreements. Swap transactions may involve substantial leverage.
Forward Currency Exchange Contracts [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Forward Currency Exchange Contracts The use of forward currency exchange contracts may involve certain risks, including the failure of the counterparty to perform its obligations under the contract and that the use of forward contracts may not serve as a complete hedge because of an imperfect correlation between movements in the prices of the contracts and the prices of the currencies hedged or used for cover.
Dependence On Key Personnel [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Dependence on Key Personnel Mr. Mario J. Gabelli is a portfolio manager of the Fund. The Investment Adviser is dependent upon the expertise of Mr. Gabelli in providing advisory services with respect to the Fund’s investments. If the Investment Adviser were to lose the services of Mr. Gabelli, its ability to service the Fund could be adversely affected. There can be no assurance that a suitable replacement could be found for Mr. Gabelli in the event of his death, resignation, retirement or inability to act on behalf of the Investment Adviser.
Coronavirus C O V I D 19 And Global Health Event Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Coronavirus (“COVID-19”) and Global Health Event Risk An outbreak of a highly contagious novel coronavirus known as “COVID 19” that was first declared in December 2019 developed into a global pandemic that had a devastating impact on the global economy, including the U.S. economy, and resulted in a global economic recession. Many states issued orders requiring the closure of non essential businesses and/or requiring residents to stay at home. The COVID 19 pandemic and preventative measures taken to contain or mitigate its spread caused business shutdowns, cancellations of events and travel, significant reductions in demand for certain goods and services, reductions in business activity and financial transactions, supply chain interruptions and overall economic and financial market instability both globally and in the United States. The U.S. economy and most other major global economies may continue to experience a substantial economic downturn or recession, and our business and operations, as well as the business and operations of our portfolio companies, could be materially adversely affected by a prolonged economic downturn or recession in the United States and other major markets. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time. These events could have a significant impact on the Fund’s performance, NAV, income, operating results and ability to pay distributions, as well as the performance, income, operating results and viability of issuers in which it invests.
Market Disruption And Geopolitical Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Market Disruption and Geopolitical Risk The consequences of the conflict between Russia and Ukraine, including international sanctions, further impact on inflation and increased disruption to supply chains may impact our portfolio companies, result in an economic downturn or recession either globally or locally in the U.S. or other economies, reduce business activity, spawn additional conflicts (whether in the form of traditional military action, reignited “cold” wars or in the form of virtual warfare such as cyberattacks) with similar and perhaps wider ranging impacts and consequences and have an adverse impact on the Fund’s returns and NAV. The occurrence of events similar to those in recent years, such as localized wars, instability, new and ongoing pandemics (such as COVID-19), epidemics or outbreaks of infectious diseases in certain parts of the world, natural/environmental disasters, terrorist attacks in the United States and around the world, social and political discord, debt crises sovereign debt downgrades, increasingly strained relations between the United States and a number of foreign countries, new and continued political unrest in various countries, the exit or potential exit of one or more countries from the European Union (“EU”) or the Economic and Monetary Union, continued changes in the balance of political power among and within the branches of the U.S. government, government shutdowns, among others, may result in market volatility, may have long term effects on the U.S. and worldwide financial markets, and may cause further economic uncertainties in the United States and worldwide. The current contentious domestic political environment, as well as political and diplomatic events within the United States and abroad, such as the U.S. government’s inability at times to agree on a long-term budget and deficit reduction plan, may in the future result in government shutdowns, which could have a material adverse effect on the Fund’s investments and operations. In addition, the Fund’s ability to raise additional capital in the future through the sale of securities could be materially affected by a government shutdown. Additional and/or prolonged U.S. government shutdowns may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree. In particular, the escalation of the conflict between Russia and Ukraine, including international sanctions, further impact on inflation and increased disruption to supply chains may impact our portfolio companies. Such unfavorable economic conditions also may also be expected to increase our funding costs, limit our access to the capital markets or result in a decision by lenders not to extend credit to us. The current political climate has intensified concerns about a potential trade war between China and the United States, as each country has recently imposed tariffs on the other country’s products. These actions may trigger a significant reduction in international trade, the oversupply of certain manufactured goods, substantial price reductions of goods and possible failure of individual companies and/or large segments of China’s export industry, which could have a negative impact on our performance. U.S. companies that source material and goods from China and those that make large amounts of sales in China would be particularly vulnerable to an escalation of trade tensions. Uncertainty regarding the outcome of the trade tensions and the potential for a trade war could cause the U.S. dollar to decline against safe haven currencies, such as the Japanese yen and the euro. Events such as these and their consequences are difficult to predict and it is unclear whether further tariffs may be imposed or other escalating actions may be taken in the future. Any of these effects could have a material adverse effect on our business, financial condition and results of operations. On January 31, 2020, the United Kingdom officially left the European Union (“Brexit”), subject to a transitional period that ended December 31, 2020. The United Kingdom and European Union have reached an agreement on the terms of their future trading relationship effective January 1, 2021, which principally relates to the trading of goods rather than services, including financial services. Further discussions are to be held between the United Kingdom and the European Union in relation to matters not covered by the trade agreement, such as financial services. The Fund faces risks associated with the potential uncertainty and consequences that may follow Brexit, including with respect to volatility in exchange rates and interest rates. Brexit could adversely affect European or worldwide political, regulatory, economic or market conditions and could contribute to instability in global political institutions, regulatory agencies and financial markets. Brexit has also led to legal uncertainty and could lead to politically divergent national laws and regulations as a new relationship between the United Kingdom and European Union is defined and the United Kingdom determines which European Union laws to replace or replicate. Any of these effects of Brexit could adversely affect any of the companies to which the Fund has exposure and any other assets that the Fund invests in. The political, economic and legal consequences of Brexit are not yet known. In the short term, financial markets may experience heightened volatility, particularly those in the United Kingdom and Europe, but possibly worldwide. The United Kingdom and Europe may be less stable than they have been in recent years, and investments in the United Kingdom and the European Union may be difficult to value or subject to greater or more frequent volatility. In the longer term, there is likely to be a period of significant political, regulatory and commercial uncertainty as the United Kingdom continues to negotiate the terms of its future trading relationship with the European Union. While the extreme volatility and disruption that U.S. and global markets experienced for an extended period of time beginning in 2007 and 2008 had, until the recent coronavirus (COVID-19) outbreak, generally subsided, uncertainty and periods of volatility still remain, and risks to a robust resumption of growth persist. Federal Reserve policy, including with respect to certain interest rates, may adversely affect the value, volatility and liquidity of dividend and interest paying securities. Market volatility, dramatic changes to interest rates and/or a return to unfavorable economic conditions may lower the Fund’s performance or impair the Fund’s ability to achieve its investment objective. Cybersecurity incidents affecting particular companies or industries may adversely affect the economies of particular countries, regions or parts of the work in which the Fund invests. The occurrence of any of these above events could have a significant adverse impact on the value and risk profile of the Fund’s portfolio. The Fund does not know how long the securities markets may be affected by similar events and cannot predict the effects of similar events in the future on the U.S. economy and securities markets. There can be no assurance that similar events and other market disruptions will not have other material and adverse implications.
Economic Events And Market Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Economic Events and Market Risk Periods of market volatility may continue to occur in the future, in response to various political, social and economic events both within and outside of the United States. These conditions have resulted in, and in many cases continue to result in, greater price volatility, less liquidity, widening credit spreads and a lack of price transparency, with many securities remaining illiquid and of uncertain value. Such market conditions may adversely affect the Fund, including by making valuation of some of the Fund’s securities uncertain and/or result in sudden and significant valuation increases or declines in the Fund’s holdings. If there is a significant decline in the value of the Fund’s portfolio, this may impact the asset coverage levels for the Fund’s outstanding leverage. Risks resulting from any future debt or other economic crisis could also have a detrimental impact on the global economic recovery, the financial condition of financial institutions and our business, financial condition and results of operation. Market and economic disruptions have affected, and may in the future affect, consumer confidence levels and spending, personal bankruptcy rates, levels of incurrence and default on consumer debt and home prices, among other factors. To the extent uncertainty regarding the U.S. or global economy negatively impacts consumer confidence and consumer credit factors, our business, financial condition and results of operations could be significantly and adversely affected. Downgrades to the credit ratings of major banks could result in increased borrowing costs for such banks and negatively affect the broader economy. Moreover, Federal Reserve policy, including with respect to certain interest rates, may also adversely affect the value, volatility and liquidity of dividend- and interest-paying securities. Market volatility, rising interest rates and/ or a return to unfavorable economic conditions could impair the Fund’s ability to achieve its investment objective.
Regulation And Government Intervention Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Regulation and Government Intervention Risk. Federal, state, and other governments, their regulatory agencies or self-regulatory organizations may take actions that affect the regulation of the issuers in which the Fund invests in ways that are unforeseeable. Legislation or regulation may also change the way in which the Fund is regulated. Such legislation or regulation could limit or preclude the Fund’s ability to achieve its investment objective. In light of popular, political and judicial focus on finance related consumer protection, financial institution practices are also subject to greater scrutiny and criticism generally. In the case of transactions between financial institutions and the general public, there may be a greater tendency toward strict interpretation of terms and legal rights in favor of the consuming public, particularly where there is a real or perceived disparity in risk allocation and/or where consumers are perceived as not having had an opportunity to exercise informed consent to the transaction. In the event of conflicting interests between retail investors holding common shares of a closed-end investment company such as the Fund and a large financial institution, a court may similarly seek to strictly interpret terms and legal rights in favor of retail investors. The Fund may be affected by governmental action in ways that are not foreseeable, and there is a possibility that such actions could have a significant adverse effect on the Fund and its ability to achieve its investment objective.
Inflation Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Inflation Risk Inflation risk is the risk that the value of assets or income from investments will be worth less in the future as inflation decreases the value of money. Inflation rates may change frequently and drastically as a result of various factors, including unexpected shifts in the domestic or global economy. As inflation increases, the real value of the Fund’s shares and distributions therefore may decline. In addition, during any periods of rising inflation, dividend rates of any debt securities issued by the Fund would likely increase, which would tend to further reduce returns to the Fund’s common shareholders.
Deflation Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Deflation Risk Deflation risk is the risk that prices throughout the economy decline over time, which may have an adverse effect on the market valuation of companies, their assets and their revenues. In addition, deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund’s portfolio.
Anti Takeover Provisions Of The Funds Governing Documents [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Anti-Takeover Provisions of the Fund’s Governing Documents The Fund’s Agreement and Declaration of Trust as amended and supplemented (including the statements of preferences thereto) and bylaws, as amended from time to time, include provisions that could limit the ability of other entities or persons to acquire control of the Fund or convert the Fund to an open-end fund.
Special Risks Related To Fund Investments In Preferred Securities [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Special Risks Related to Fund Investments in Preferred Securities There are special risks associated with the Fund’s investing in preferred securities, including: ● Deferral. ● Non-Cumulative Dividends. ● Subordination. ● Liquidity. ● Limited Voting Rights. the issuer’s board. Generally, once all the arrearages have been paid, the preferred security holders no longer have voting rights. ● Special Redemption Rights. ● Phantom Income.
Special Risks To Holders Of Notes [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Special Risks to Holders of Notes There may not be an established market for our notes. To the extent that our notes trade, they may trade at a price either higher or lower than their principal amount depending on interest rates, the rating (if any) on such notes and other factors.
Special Risks To Holder Of Notes [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Special Risks to Holders of Notes There may not be an established market for our notes. To the extent that our notes trade, they may trade at a price either higher or lower than their principal amount depending on interest rates, the rating (if any) on such notes and other factors.
Investment Companies [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Investment Companies The Fund may invest in the securities of other investment companies to the extent permitted by law. To the extent the Fund invests in the common equity of investment companies, the Fund will bear its ratable share of any such investment company’s expenses, including management fees. The Fund will also remain obligated to pay management fees to the Investment Adviser with respect to the assets invested in the securities of other investment companies. In these circumstances holders of the Fund’s common shares will be subject to duplicative investment expenses.
Counterparty Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Counterparty Risk The Fund will be subject to credit risk with respect to the counterparties to the derivative contracts purchased by the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery under the derivative contract in bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances.
Loans Of Portfolio Securities [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Loans of Portfolio Securities Consistent with applicable regulatory requirements and the Fund’s investment restrictions, the Fund may lend its portfolio securities to securities broker-dealers or financial institutions, provided that such loans are callable at any time by the Fund (subject to certain notice provisions) and are at all times secured by cash or cash equivalents, which are maintained in a segregated account pursuant to applicable regulations and that are at least equal to the market value, determined daily, of the loaned securities. The advantage of such loans is that the Fund continues to receive the income on the loaned securities while at the same time earning interest on the cash amounts deposited as collateral, which will be invested in short term liquid obligations. The Fund will not lend its portfolio securities if such loans are not permitted by the laws or regulations of any state in which its shares are qualified for sale. The Fund’s loans of portfolio securities will be collateralized in accordance with applicable regulatory requirements, which means that “cash equivalents” accepted as collateral will be limited to securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities or irrevocable letters of credit issued by a bank (other than the Fund’s bank lending agent, if any, or a borrower of the Fund’s portfolio securities or any affiliate of such bank or borrower) which qualifies as a custodian bank for an investment company under the 1940 Act.
Management Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Management Risk The Fund is subject to management risk because it is an actively managed portfolio. The Investment Adviser applies investment techniques and risk analyses in making investment decisions for the Fund, but there can be no guarantee that these will produce the desired results.
Status As Regulated Investment Company [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Status as a Regulated Investment Company The Fund has qualified, and intends to remain qualified, for federal income tax purposes as a regulated investment company under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). Qualification requires, among other things, compliance by the Fund with certain distribution requirements. Statutory limitations on distributions on the common shares if the Fund fails to satisfy the 1940 Act’s asset coverage requirements could jeopardize the Fund’s ability to meet such distribution requirements. The Fund presently intends, however, to purchase or redeem preferred shares to the extent necessary in order to maintain compliance with such asset coverage requirements.
Leverage Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Leverage Risk The Fund’s leveraged capital structure creates special risks not associated with unleveraged funds having similar investment objectives and policies. The Fund uses financial leverage for investment purposes by issuing preferred shares and notes. As of December 31, 2023, the amount of leverage represented approximately 24% of the Fund’s total net assets. All series of the Fund’s preferred shares have the same seniority with respect to distributions and liquidation preference. Preferred shares have seniority over common shares with respect to distributions and upon liquidation of the Fund. The Fund’s notes have higher priority in the Fund’s capital structure than the Fund’s common shares and preferred shares and, therefore, the Fund’s notes have seniority over such shares with respect to the payment of interest and upon the distribution of the Fund’s assets. The Fund’s use of leverage, which can be described as exposure to changes in price at a ratio greater than the amount of equity invested, either through the issuance of preferred shares, borrowings, including notes, or other forms of market exposure, magnifies both the favorable and unfavorable effects of price movements in the investments made by the Fund. The Fund’s leveraged capital structure creates special risks not associated with unleveraged funds having similar investment objectives and policies. The Fund cannot assure that the issuance of preferred shares or notes will result in a higher yield or return to the holders of the common shares. Also, as the Fund is utilizing leverage, a decline in NAV could affect the ability of the Fund to make common share distributions and such a failure to pay dividends or make distributions could result in the Fund ceasing to qualify as a regulated investment company under the Code. ● Special Risks of Preferred Shares to Holders of Common Shares. the Fund’s portfolio, the leverage will result in a lower rate of return to the holders of common shares than if the Fund had not issued preferred shares. Any decline in the NAV of the Fund’s investments would be borne entirely by the holders of common shares. Therefore, if the market value of the Fund’s portfolio declines, the leverage will result in a greater decrease in NAV to the holders of common shares than if the Fund were not leveraged. This greater NAV decrease will also tend to cause a greater decline in the market price for the common shares. The Fund might be in danger of failing to maintain the required asset coverage of the preferred shares or of losing its ratings on the preferred shares or, in an extreme case, the Fund’s current investment income might not be sufficient to meet the dividend requirements on the preferred shares. In order to counteract such an event, the Fund might need to liquidate investments in order to fund a redemption of some or all of the preferred shares. In addition, the Fund would pay (and the holders of common shares will bear) all costs and expenses relating to the issuance and ongoing maintenance of the preferred shares, including the advisory fees on the incremental assets attributable to such shares. Holders of preferred shares may have different interests than holders of common shares and may at times have disproportionate influence over the Fund’s affairs. Holders of preferred shares, voting separately as a single class, would have the right to elect two members of the Board at all times and in the event dividends become two full years in arrears would have the right to elect a majority of the Trustees until such arrearage is completely eliminated. In addition, preferred shareholders have class voting rights on certain matters, including changes in fundamental investment restrictions and conversion of the Fund to open-end status, and accordingly can veto any such changes. Restrictions imposed on the declarations and payment of dividends or other distributions to the holders of the Fund’s common shares and preferred shares, both by the 1940 Act and by requirements imposed by rating agencies, might impair the Fund’s ability to maintain its qualification as a regulated investment company for federal income tax purposes. While the Fund intends to redeem its preferred shares to the extent necessary to enable the Fund to distribute its income as required to maintain its qualification as a regulated investment company under the Code, there can be no assurance that such actions can be effected in time to meet the Code requirements. ● Special Risks of Notes to Holders of Common Shares. maintain the specified level of asset coverage of any notes outstanding, the holders of the notes will have the right to elect a majority of the Fund’s trustees. ● Portfolio Guidelines of Rating Agencies for Preferred Shares and/or Credit Facility. ● Impact on Common Shares. Assumed Return on Portfolio (Net of Expenses) (10.00 )% (5.00 )% 0.00 % 5.00 % 10.00 % Corresponding Return to Common Shareholder (15.18 )% (8.60 )% (2.02 )% 4.56 % 11.15 % Common share total return is composed of two elements — the common share distributions paid by the Fund (the amount of which is largely determined by the taxable income of the Fund (including realized gains or losses) after paying interest on any debt, including any notes, and/or dividends on any preferred shares) and unrealized gains or losses on the value of the securities the Fund owns. As required by SEC rules, the table assumes that the Fund is more likely to suffer capital losses than to enjoy total return. For example, to assume a total return of 0% the Fund must assume that the income it receives on its investments is entirely offset by expenses and losses in the value of those investments. The Fund’s shares are leveraged and the risks and special considerations related to leverage described in this prospectus apply. Such leveraging of the shares cannot be fully achieved until the proceeds resulting from the use of leverage have been invested in accordance with the Fund’s investment objectives and policies.
Special Risks To Holders Of Fixed Rate Preferred Shares [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Special Risks to Holders of Fixed Rate Preferred Shares ● Illiquidity Prior to Exchange Listing. ● Market Price Fluctuation.
Special Risks For Holders Of Subscription Rights [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Special Risks for Holders of Subscription Rights The issuance of subscription rights to purchase our common shares may substantially dilute the aggregate NAV of the common shares owned by shareholders who do not fully exercise their rights in the offering. Shareholders who do not exercise their rights to purchase common shares will own a smaller proportional interest in the Fund than they did before the offering. In the case of subscription rights for preferred shares, there is a risk that changes in yield or changes in the credit quality of the Fund may result in the underlying preferred shares purchasable upon exercise of the subscription rights being less attractive to investors at the conclusion of the subscription period. This may reduce or eliminate the value of the subscription rights for the preferred shares. Investors who receive subscription rights may find that there is no market to sell rights they do not wish to exercise. If investors exercise only a portion of the rights, the number of preferred shares or common shares issued may be reduced, and the preferred shares or common shares may trade at less favorable prices than larger offerings for similar securities.
Common Share Distribution Policy Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Common Share Distribution Policy Risk The Fund has adopted a policy, which may be changed at any time by the Board, of paying distributions on its common shares of $0.05 per share per month. In the event the Fund does not generate a total return from dividends and interest received and net realized capital gains in an amount equal to or in excess of its stated distribution in a given year, the Fund may return capital as part of such distribution, which may have the effect of decreasing the asset coverage per share with respect to the Fund’s preferred shares. Any return of capital should not be considered by investors as yield or total return on their investment in the Fund. Shareholders should not assume that a distribution from the Fund is comprised exclusively of net profits. For the fiscal year ended December 31, 2023, the Fund made distributions of $0.60 per common share, of which approximately $0.54 per share is deemed a return of capital. The Fund has made monthly distributions with respect to its common shares since October 1999. A portion of the distributions to holders of common shares during nineteen of the twenty-three fiscal years since the Fund’s inception has constituted a return of capital. The composition of each distribution is estimated based on the earnings of the Fund as of the record date for each distribution. The actual composition of each of the current year’s distributions will be based on the Fund’s investment activity through the end of the calendar year.
Investment Restrictions [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Investment Restrictions The Fund has adopted certain investment limitations designed to limit investment risk and maintain portfolio diversification. These limitations are fundamental and may not be changed without the approval of the holders of a majority, as defined in the 1940 Act, of the outstanding shares of common shares and preferred shares voting together as a single class. The Fund may become subject to guidelines that are more limiting than the investment restrictions set forth above in order to obtain and maintain ratings from Moody’s or Fitch Ratings Inc. on its preferred shares. See “Leverage Risk — Portfolio Guidelines of Rating Agencies for Preferred Shares and/or Credit Facility.”
Interest Rate Transactions [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Interest Rate Transactions The Fund may enter into interest rate swap or cap transactions in relation to all or a portion of the Fund’s Series B Auction Market Preferred Shares (the “Series B Preferred”) in order to manage the impact on its portfolio of changes in the dividend rate of such shares. At present, the Fund has not entered into an interest rate swap on a percentage of its outstanding Series B Preferred. Through these transactions the Fund may, for example, obtain the equivalent of a fixed rate for the Series B Preferred that is lower than the Fund would have to pay if it issued Fixed Rate Preferred Shares. The use of interest rate swaps and caps is a highly specialized activity that involves certain risks to the Fund including, among others, counterparty risk and early termination risk. The use of interest rate swaps and caps is a highly specialized activity that involves investment techniques and risks different from those associated with ordinary portfolio security transactions. In an interest rate swap, the Fund would agree to pay to the other party to the interest rate swap (which is known as the “counterparty”) periodically a fixed rate payment in exchange for the counterparty agreeing to pay to the Fund periodically a variable rate payment that is intended to approximate the Fund’s variable rate payment obligation on its Series B Preferred. In an interest rate cap, the Fund would pay a premium to the counterparty to the interest rate cap and, to the extent that a specified variable rate index exceeds a predetermined fixed rate, would receive from the counterparty payments of the difference based on the notional amount of such cap. Interest rate swap and cap transactions introduce additional risk because the Fund would remain obligated to pay preferred shares dividends or distributions when due in accordance with the statement of preferences of the Series B Preferred even if the counterparty defaulted. Depending on the general state of short term interest rates and the returns on the Fund’s portfolio securities at that point in time, such a default could negatively affect the Fund’s ability to make dividend or distribution payments on the Series B Preferred. In addition, at the time an interest rate swap or cap transaction reaches its scheduled termination date, there is a risk that the Fund will not be able to obtain a replacement transaction or that the terms of the replacement will not be as favorable as on the expiring transaction. If this occurs, it could have a negative impact on the Fund’s ability to make dividend or distribution payments on the Series B Preferred. To the extent there is a decline in interest rates, the value of the interest rate swap or cap could decline, resulting in a decline in the asset coverage for the Series B Preferred. A sudden and dramatic decline in interest rates may result in a significant decline in the asset coverage. Under the statement of preferences for each series of the preferred shares, if the Fund fails to maintain the required asset coverage on the outstanding preferred shares or fails to comply with other covenants, the Fund may be required to redeem some or all of these shares. The Fund generally may redeem the Series B Preferred, in whole or in part, at its option at any time (usually on a dividend or distribution payment date), other than during a non-call period. Such redemption would likely result in the Fund seeking to terminate early all or a portion of any swap or cap transactions. Early termination of a swap could result in a termination payment by the Fund to the counterparty, while early termination of a cap could result in a termination payment to the Fund. The Fund will usually enter into swaps or caps on a net basis; that is, the two payment streams will be netted out in a cash settlement on the payment date or dates specified in the instrument, with the Fund receiving or paying, as the case may be, only the net amount of the two payments. The Fund will monitor any such swap with a view to ensuring that the Fund remains in compliance with all applicable regulatory investment policy and tax requirements.
Legislation Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Legislation Risk At any time after the date of this report, legislation may be enacted that could negatively affect the assets of the Fund. Legislation or regulation may change the way in which the Fund itself is regulated. The Investment Adviser cannot predict the effects of any new governmental regulation that may be implemented and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s ability to achieve its investment objective.
Reliance On Service Providers Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Reliance on Service Providers Risk The Fund must rely upon the performance of service providers to perform certain functions, which may include functions that are integral to the Fund’s operations and financial performance. Failure by any service provider to carry out its obligations to the Fund in accordance with the terms of its appointment, to exercise due care and skill or to perform its obligations to the Fund at all as a result of insolvency, bankruptcy or other causes could have a material adverse effect on the Fund’s performance and returns to shareholders. The termination of the Fund’s relationship with any service provider, or any delay in appointing a replacement for such service provider, could materially disrupt the business of the Fund and could have a material adverse effect on the Fund’s performance and returns to shareholders.
Cyber Security Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Cyber Security Risk The Fund and its service providers are susceptible to cyber security risks that include, among other things, theft, unauthorized monitoring, release, misuse, loss, destruction or corruption of confidential and highly restricted data; denial of service attacks; unauthorized access to relevant systems, compromises to networks or devices that the Fund and its service providers use to service the Fund’s operations; or operational disruption or failures in the physical infrastructure or operating systems that support the Fund and its service providers. Cyber attacks against or security breakdowns of the Fund or its service providers may adversely impact the Fund and its shareholders, potentially resulting in, among other things, financial losses; the inability of Fund shareholders to transact business and the Fund to process transactions; inability to calculate the Fund’s NAV; violations of applicable privacy and other laws; regulatory fines, penalties, reputational damage, reimbursement or other compensation costs; and/or additional compliance costs. The Fund may incur additional costs for cyber security risk management and remediation purposes. In addition, cyber security risks may also impact issuers of securities in which the Fund invests, which may cause the Fund’s investment in such issuers to lose value. There can be no assurance that the Fund or its service providers will not suffer losses relating to cyber attacks or other information security breaches in the future.
Misconduct Of Employees And Of Service Providers Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Misconduct of Employees and of Service Providers Risk Misconduct or misrepresentations by employees of the Investment Adviser or the Fund’s service providers could cause significant losses to the Fund. Employee misconduct may include binding the Fund to transactions that exceed authorized limits or present unacceptable risks and unauthorized trading activities, concealing unsuccessful trading activities (which, in any case, may result in unknown and unmanaged risks or losses) or making misrepresentations regarding any of the foregoing. Losses could also result from actions by the Fund’s service providers, including, without limitation, failing to recognize trades and misappropriating assets. In addition, employees and service providers may improperly use or disclose confidential information, which could result in litigation or serious financial harm, including limiting the Fund’s business prospects or future marketing activities. Despite the Investment Adviser’s due diligence efforts, misconduct and intentional misrepresentations may be undetected or not fully comprehended, thereby potentially undermining the Investment Adviser’s due diligence efforts. As a result, no assurances can be given that the due diligence performed by the Investment Adviser will identify or prevent any such misconduct.
Senior Securities Leverage [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Senior Securities / leverage As of December 31, 2023, the Fund uses leverage through the issuance of preferred shares and notes.
Effects Of Leverage [Member]
General Description of Registrant [Abstract]
Risk [Text Block]									Effects of Leverage The following information is furnished in response to requirements of the SEC. It is designed to, among other things, illustrate the effects of leverage through the use of senior securities, as that term is defined under Section 18 of the 1940 Act, on Common Share total return, assuming investment portfolio total returns (consisting of income and changes in the value of investments held in a Fund’s portfolio) of -10%, -5%, 0%, 5% and 10%. The table below reflects the Fund’s continued use of preferred shares and notes, as of December 31, 2023 as a percentage of total managed assets (including assets attributable to such leverage), the estimated annual effective preferred shares dividend rate and interest expense rate payable by the Fund on notes (based on market conditions as of December 31, 2023), and the annual return that the Fund’s portfolio must experience (net of expenses) in order to cover such costs. The information below does not reflect the Fund’s use of certain other forms of economic leverage achieved through the use of other instruments or transactions not considered to be senior securities under the 1940 Act, such as derivative instruments. The assumed investment portfolio returns in the table below are hypothetical figures and are not necessarily indicative of the investment portfolio returns experienced or expected to be experienced by the Fund. Your actual returns may be greater or less than those appearing below. Preferred Shares and Principal Value of Notes as a Percentage of Total Managed Assets (Including Assets Attributable to Preferred Shares and Notes) 24 % Estimated Annual Effective Preferred Share Dividend and Interest on Note Rate 5.34 % Annual Return Fund Portfolio Must Experience (net of expenses) to Cover Estimated Annual Effective Preferred Share Dividend and Interest on Note Rate 1.31 % Common Share Total Return for (10.00)% Assumed Portfolio Total Return (15.18 )% Common Share Total Return for (5.00)% Assumed Portfolio Total Return (8.60 )% Common Share Total Return for 0.00% Assumed Portfolio Total Return (2.02 )% Common Share Total Return for 5.00% Assumed Portfolio Total Return 4.56 % Common Share Total Return for 10.00% Assumed Portfolio Total Return 11.15 % Common shares total return is composed of two elements — the distributions paid by a Fund to holders of common shares (the amount of which is largely determined by the net investment income of the Fund after paying dividend payments on any preferred shares issued by the Fund and expenses on any forms of leverage outstanding, such as notes) and gains or losses on the value of the securities and other instruments the Fund owns. As required by SEC rules, the table assumes that a Fund is more likely to suffer capital losses than to enjoy capital appreciation. For example, to assume a total return of 0%, a Fund must assume that the income it receives on its investments is entirely offset by losses in the value of those investments. This table reflects hypothetical performance of the Fund’s portfolio and not the actual performance of the Fund’s common shares, the value of which is determined by market forces and other factors. Should the Fund elect to add additional leverage to its portfolio, any benefits of such additional leverage cannot be fully achieved until the proceeds resulting from the use of such leverage have been received by the Fund and invested in accordance with the Fund’s investment objectives and policies. As noted above, the Fund’s willingness to use additional leverage, and the extent to which leverage is used at any time, will depend on many factors, including, among other things, the Fund’s assessment of the yield curve environment, interest rate trends, market conditions and other factors.
Dividends On Preferred Shares Not Included [Member]
Other Annual Expenses [Abstract]
Expense Example, Year 01									$ 19
Expense Example, Years 1 to 3									60
Expense Example, Years 1 to 5									103
Expense Example, Years 1 to 10									$ 222