The Cushing MLP & Infrastructure Total Return Fund (SRV)
Company Profile
| N-2 - USD ($) | 3 Months Ended | 12 Months Ended | ||||||||||||
| Nov. 30, 2023 | Aug. 31, 2023 | May 31, 2023 | Feb. 28, 2023 | Nov. 30, 2022 | Aug. 31, 2022 | May 31, 2022 | Feb. 28, 2022 | Nov. 30, 2021 | Aug. 31, 2021 | May 31, 2021 | Feb. 28, 2021 | Nov. 30, 2023 | ||
| Cover [Abstract] | ||||||||||||||
| Entity Central Index Key | 0001400897 | |||||||||||||
| Amendment Flag | false | |||||||||||||
| Entity Inv Company Type | N-2 | |||||||||||||
| Document Type | N-CSR | |||||||||||||
| Entity Registrant Name | NXG Cushing Midstream Energy Fund | |||||||||||||
| Fee Table [Abstract] | ||||||||||||||
| Shareholder Transaction Expenses [Table Text Block] | Shareholder transaction expenses Sales load ( as a percentage of estimated offering price — % (1) Offering expenses borne by the Fund (as a percentage of estimated offering price) — % (1) Dividend reinvestment plan fees (per transaction sales fee) $ 15.00 (2) (1) If Common Shares to which this Report relates are sold to or through underwriters, the Prospectus Supplement will set forth any applicable sales load and the estimated offering expenses borne by the Fund. (2) | |||||||||||||
| Sales Load [Percent] | [1] | |||||||||||||
| Dividend Reinvestment and Cash Purchase Fees | [2] | $ 15 | ||||||||||||
| Other Transaction Expenses [Abstract] | ||||||||||||||
| Other Transaction Expenses [Percent] | [1] | |||||||||||||
| Annual Expenses [Table Text Block] | Annual Expenses Percentage of Net Assets (3) Management fees (4)(5) 1.52 % Interest payments on borrowed funds (6) 1.46 % Other expenses (7) 0.76 % Total annual expenses before waiver 3.74 % Fee waiver (5) (0.31 ) Total annual expenses after fee waiver 3.43 % (3) Based upon net assets attributable to common shares as of November 30, 2023. (4) The Fund pays the Investment Adviser an annual fee, payable monthly, in an amount equal to 1.25% of the Fund’s average weekly Managed Assets. The fee shown above is based upon outstanding leverage of 19% of the Fund’s Managed Assets (or 23% of the Fund’s net assets attributable to common shares). If leverage of more than 19% of the Fund’s Managed Assets (or 23% of the Fund’s net assets attributable to common shares) is used, the management fees, as a percentage of net assets attributable to common shares would be higher than as shown above. (5) The Investment Adviser has contractually agreed to waive a portion of the management fee in the amount equal to 0.25% of the Fund’s Managed Assets through February 1, 2025. (6) Based upon the Fund’s outstanding borrowings as of November 30, 2023 of $19,315,000 million and the interest rate as of November 30, 2023, of 6.46%. (7) “Other expenses” are estimated based upon those incurred during the fiscal period ended November 30, 2023. Other expenses do not include expense related to realized or unrealized investment gains or losses. See “Additional Information (Unaudited)—Management of the Fund—Fund Expenses.” | |||||||||||||
| Management Fees [Percent] | [3],[4],[5] | 1.52% | ||||||||||||
| Interest Expenses on Borrowings [Percent] | [3],[6] | 1.46% | ||||||||||||
| Other Annual Expenses [Abstract] | ||||||||||||||
| Other Annual Expenses [Percent] | [3],[7] | 0.76% | ||||||||||||
| Total Annual Expenses [Percent] | [3] | 3.74% | ||||||||||||
| Waivers and Reimbursements of Fees [Percent] | (0.31%) | |||||||||||||
| Net Expense over Assets [Percent] | [3] | 3.43% | ||||||||||||
| Expense Example [Table Text Block] | EXAMPLE As required by relevant SEC regulations, the following example illustrates the expenses that you would pay on a $1,000 investment in Common Shares, assuming (1) Total annualized expenses of 3.43% of net assets attributable to Common Shares in year 1, and total annualized expenses of 3.74% of net assets attributable to Common Shares in years 2 through 10, and (2) a 5% annual return * 1 Year 3 Years 5 Years 10 Years Total expenses incurred $ 35 $ 105 $ 177 $ 370 * The example should not be considered a representation of future expenses or returns. Actual expenses may be greater or less than those shown. | |||||||||||||
| Expense Example, Year 01 | [8] | $ 35 | ||||||||||||
| Expense Example, Years 1 to 3 | [8] | 105 | ||||||||||||
| Expense Example, Years 1 to 5 | [8] | 177 | ||||||||||||
| Expense Example, Years 1 to 10 | [8] | $ 370 | ||||||||||||
| Purpose of Fee Table , Note [Text Block] | The following table contains information about the costs and expenses that Common Shareholders will bear directly or indirectly. The table is based on the capital structure of the Fund as of November 30, 2023 (except as noted below). The purpose of the table and the example below is to help you understand the fees and expenses that you, as a holder of Common Shares, would bear directly or indirectly. | |||||||||||||
| Basis of Transaction Fees, Note [Text Block] | as a percentage of estimated offering price | |||||||||||||
| Other Expenses, Note [Text Block] | “Other expenses” are estimated based upon those incurred during the fiscal period ended November 30, 2023. Other expenses do not include expense related to realized or unrealized investment gains or losses. See “Additional Information (Unaudited)—Management of the Fund—Fund Expenses.” | |||||||||||||
| Management Fee not based on Net Assets, Note [Text Block] | If leverage of more than 19% of the Fund’s Managed Assets (or 23% of the Fund’s net assets attributable to common shares) is used, the management fees, as a percentage of net assets attributable to common shares would be higher than as shown above. | |||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Investment Objectives and Practices [Text Block] | INVESTMENT OBJECTIVE AND POLICIES Investment Objective The Fund’s investment objective is to obtain a high after-tax total return from a combination of capital appreciation and current income. There can be no assurance that the Fund’s investment objective will be achieved. Principal Investment Policies The Fund seeks to achieve its investment objective by investing, under normal market conditions, at least 80% of Managed Assets (as defined in this report) in a portfolio of midstream energy investments (the “80% policy”). For purposes of the Fund’s 80% policy, midstream energy investments are investments that offer economic exposure to securities of midstream energy companies, which are companies that provide midstream energy services, including the gathering, transporting, processing, fractionation, storing, refining and distribution of natural resources, such as natural gas, natural gas liquids, crude oil refined petroleum products, biofuels, carbon sequestration, solar, and wind. The Fund considers a company to be a midstream energy company if at least 50% of its assets, income, sales or profits are committed to or derived from midstream energy services. The Fund invests in equity and debt securities of midstream energy companies, and invests in U.S. and non-U.S. securities and in issuers of any market capitalization size. As an alternative to holding investments directly, the Fund may obtain investment exposure through derivatives transactions intended to replicate, modify or replace the economic attributes associated with investment in securities in which the Fund is permitted to invest directly. To the extent that the Fund invests in synthetic investments with economic characteristics similar to investments in midstream energy companies, the market value (or, if market value is unavailable, the fair value) of such investments will be counted for purposes of the Fund’s policy of investing at least 80% of its Managed Assets in a portfolio of midstream energy investments. For a discussion of derivative instruments in which the Fund may invest, see “Additional Information (Unaudited)—Additional Investment Practices—Strategic Transactions.” The Fund has previously qualified, and intends to continue to qualify, to be treated as a regulated investment company (“RIC”) under the Internal Revenue Code of 1986, as amended (the “Code”). The Fund pursues its investment objective by generally investing in MLPs up to the maximum extent permitted of a RIC under the Code. Accordingly, the Fund will, as of the end of each fiscal quarter, invest no more than 25% of Managed Assets in securities of MLPs and other entities that are “qualified publicly traded partnerships” under the Code. The Fund generally seeks to invest no more than 10% of Managed Assets in any one issue and no more than 15% of Managed Assets in any one issuer, in each case, determined at the time of investment. For purposes of this limit, with respect to an investment in an MLP, an “issuer” includes both an issuer and its controlling general partner, managing member or sponsor, and an “issue” is a class of an issuer’s securities or a derivative security that tracks that class of securities. The Fund seeks attractive investment opportunities by investing in initial public offerings (“IPOs”) and secondary market issuances, private investment in public equity (“PIPE”) transactions and privately negotiated transactions, including pre-acquisition and pre-IPO equity issuances and investments in private companies. Generally, no more than 50% of the Fund’s portfolio will be in PIPE or other private or restricted securities at the time of investment. “Restricted securities” are securities that are unregistered, held by control persons of the issuer or are subject to contractual restrictions on resale. The Fund will typically acquire restricted securities in directly negotiated transactions. The Fund’s investments in restricted securities may include privately issued securities of both public and private issuers. The Fund invests up to 20% of its Managed Assets in investments other than midstream energy investments, including equity securities of issuers other than midstream energy companies. The Fund’s investments in non-U.S. securities include securities of issuers in emerging markets. The Fund’s investments in non-U.S. securities also includes non-U.S. securities represented by American Depositary Receipts (“ADRs”), which are certificates evidencing ownership of shares of a non-U.S. issuer that are issued by depositary banks and generally trade on an established market in the United States or elsewhere. The Fund invests, without limitation, in debt securities rated, at the time of investment, at least (i) B3 by Moody’s Investors Service, Inc. (“Moody’s”), (ii) B- by Standard & Poor’s Ratings Services (“S&P”) or Fitch Ratings (“Fitch”), or (iii) a comparable rating by another rating agency, and invests no more than 5% of its Managed Assets in debt securities rated below B3 by Moody’s, B- by S&P or Fitch or a comparable rating by another rating agency. Therefore, the Fund may invest in below investment grade debt securities. A debt security is considered below investment grade if it is rated below Baa3- by Moody’s or below BBB- by S&P or Fitch or a comparable rating by another rating agency. Below investment grade debt securities are often referred to as “high yield” securities or “junk bonds.” Below investment grade debt securities are regarded as having predominantly speculative characteristics with respect to capacity to pay interest and to repay principal. Debt securities in which the Fund invests may be of any maturity. The credit quality policies noted above apply only at the time a security is purchased, and the Fund is not required to dispose of a security in the event that a rating agency downgrades its assessment of the credit characteristics of a particular issue. In determining whether to retain or sell such a security, the Investment Adviser may consider such factors as the Investment Adviser’s assessment of the credit quality of the issuer of such security, the price at which such security could be sold and the rating, if any, assigned to such security by other rating agencies. Rating agencies are private services that provide ratings of the credit quality of debt obligations. Ratings assigned by a rating agency are not absolute standards of credit quality and do not evaluate market risks or the liquidity of securities. Rating agencies may fail to make timely changes in credit ratings; and an issuer’s current financial condition may be better or worse than a rating indicates. To the extent that the issuer of a security pays a rating agency for the analysis of its security, an inherent conflict of interest may exist that could affect the reliability of the rating. See “Appendix A: Description of Securities Ratings” in the Fund’s Statement of Additional Information (the “SAI”). As used in this report (except as noted below), “Managed Assets” means the total assets of the Fund, minus all accrued expenses incurred in the normal course of operations other than liabilities or obligations attributable to investment leverage, including, without limitation, investment leverage obtained through (i) indebtedness of any type (including, without limitation, borrowing through a credit facility or the issuance of debt securities), (ii) the issuance of shares of preferred stock (“preferred shares”) or other similar preference securities and/or (iii) the reinvestment of collateral received for securities loaned in accordance with the Fund’s investment objective and policies. Solely for purposes of the Fund’s 80% policy, “Managed Assets” means net assets, plus the amount of any borrowings for investment purposes. As an alternative to holding investments directly, the Fund may obtain investment exposure through derivatives transactions intended to replicate, modify or replace the economic attributes associated with investment in securities in which the Fund is permitted to invest directly. To the extent that the Fund invests in synthetic investments with economic characteristics similar to investments in midstream energy companies, the market value (or, if market value is unavailable, the fair value) of such investments will be counted for purposes of the Fund’s policy of investing at least 80% of its Managed Assets in a portfolio of midstream energy investments. For a discussion of derivative instruments in which the Fund may invest, see “Additional Information (Unaudited)—Investment Objective and Policies—Additional Investment Practices—Strategic Transactions.” The Fund’s investment objective and percentage parameters, including its 80% policy, are not fundamental policies of the Fund and may be changed without shareholder approval. Shareholders, however, will be notified in writing of any change at least 60 days prior to effecting any such change. Midstream Energy Companies Midstream energy companies’ operations are often referred to in the context of the following business segments: ● Pipeline Investments ● Processing Investments ● Exploration and Production Investments (“E&P Investments”) ● Propane Investments ● Coal Investments ● Marine Shipping Investments transportation of these products utilizing the midstream energy investments’ vessels. Transportation services are typically provided pursuant to a charter or contract, the terms of which vary depending on, for example, the length of use of a particular vessel, the amount of cargo transported, the number of voyages made, the parties operating a vessel or other factors. MLPs The Fund has previously qualified, and intends to continue to qualify, to be treated as a RIC under the Code. The Fund intends to pursue its investment objective by generally investing in MLPs up to the maximum extent permitted of a RIC under the Code. Accordingly, the Fund will, as of the end of each fiscal quarter, invest no more than 25% of Managed Assets in securities of MLPs and other entities that are “qualified publicly traded partnerships” under the Code. MLPs are formed as limited partnerships or limited liability companies and taxed as partnerships for U.S. federal income tax purposes. The securities issued by many MLPs are listed and traded on a U.S. exchange. An MLP typically issues general partner and limited partner interests, or managing member and member interests. The general partner or managing member manages and often controls, has an ownership stake in, and may receive incentive distribution payments from, the MLP. If publicly-traded, to be treated as a partnership for U.S. federal income tax purposes, an MLP must derive at least 90% of its gross income for each taxable year from qualifying sources as described in Section 7704 of the Code. These qualifying sources include natural resources-based activities such as the exploration, development, mining, production, processing, refining, transportation, storage and certain marketing of mineral or natural resources. The general partner or managing member may be structured as a private or publicly-traded corporation or other entity. The general partner or managing member typically controls the operations and management of the entity and has an up to 2% general partner or managing member interest in the entity plus, in many cases, ownership of some percentage of the outstanding limited partner or member interests. The limited partners or members, through their ownership of limited partner or member interests, provide capital to the entity, are intended to have no role in the operation and management of the entity and receive cash distributions. Due to their structure as partnerships for U.S. federal income tax purposes and the expected character of their income, MLPs generally do not pay federal income taxes. Thus, unlike investors in corporate securities, direct MLP investors are generally not subject to double taxation (i.e., corporate level tax and tax on corporate distributions). MLPs in which the Fund invests may be able to offset a significant portion of their income with tax deductions, such as accelerated depreciation. As a result, such MLPs may make cash distributions to their limited partners in excess of the amount of their taxable income allocable to their limited partners. The portion, if any, of the cash distributions received by the Fund with respect to its investment in the equity securities of an MLP that exceeds the Fund’s allocable share of the MLP’s net taxable income will not be treated as taxable income to the Fund, but rather will be treated as a tax deferred return of capital to the extent of the Fund’s basis in such MLP equity securities. MLPs are typically structured such that common units and general partner interests have first priority to receive the minimum quarterly distribution (“MQD”). Common and general partner interests also accrue arrearages in distributions to the extent the MQD is not paid. Once common units and general partner interests have been paid, subordinated units generally receive distributions; however, subordinated units generally do not accrue arrearages. The subordinated units are normally owned by the owners or affiliates of the general partner and convert on a one for one basis into common units, generally in three to five years after the MLP’s initial public offering or after certain distribution levels have been exceeded. Distributable cash in excess of the MQD is distributed to both common and subordinated units generally on a pro rata basis. The general partner is also normally eligible to receive incentive distributions if the general partner operates the business in a manner which results in payment of per unit distributions that exceed threshold levels above the MQD. As the general partner increases cash distributions to the limited partners, the general partner receives an increasingly higher percentage of the incremental cash distributions. A common arrangement provides that the general partner can reach a tier where it receives 50% of every incremental dollar distributed by the MLP. These incentive distributions encourage the general partner to increase the partnership’s cash flow and raise the quarterly cash distribution by pursuing steady cash flow investment opportunities, streamlining costs and acquiring assets. Such results benefit all security holders of the MLP. Equity securities issued by MLPs typically consist of common and subordinated units (which represent the limited partner or member interests) and a general partner or managing member interest. ● Common Units ● Subordinated Units ● General Partner or Managing Member Interests partners or members to remove the general partner or managing member without cause is typically very limited. In addition, some MLPs permit the holder of incentive distribution rights to reset, under specified circumstances, the incentive distribution levels and receive compensation in exchange for the distribution rights given up in the reset. ● I-Shares For purposes of the Fund’s limit on investment in any single issuer, with respect to an investment in an MLP, an “issuer” includes both an issuer and its controlling general partner, managing member or sponsor, and an “issue” is a class of an issuer’s securities or a derivative security that tracks that class of securities. Preferred Stock Preferred stock generally has a preference as to distributions and upon liquidation over an issuer’s common stock but ranks junior to other income securities in an issuer’s capital structure. Preferred stock generally pays distributions in cash (or additional shares of preferred stock) at a defined rate but, unlike interest payments on other income securities, preferred stock distributions are payable only if declared by the issuer’s board of directors. distributions on preferred stock may be cumulative, meaning that, in the event the issuer fails to make one or more distribution payments on the preferred stock, no distributions may be paid on the issuer’s common stock until all unpaid preferred stock distributions have been paid. Preferred stock also may provide that, in the event the issuer fails to make a specified number of distribution payments, the holders of the preferred stock will have the right to elect a specified number of directors to the issuer’s board. Preferred stock also may be subject to optional or mandatory redemption provisions. Convertible Securities A convertible security is a bond, debenture, note, preferred stock or other security that may be converted into or exchanged for a prescribed amount of common stock or other equity security of the same or a different issuer within a particular period of time at a specified price or formula. A convertible security entitles the holder to receive interest paid or accrued on debt or the distribution paid on preferred stock until the convertible security matures or is redeemed, converted or exchanged. Before conversion, convertible securities have characteristics similar to nonconvertible income securities in that they ordinarily provide a stable stream of income with generally higher yields than those of common stocks of the same or similar issuers, but lower yields than comparable nonconvertible securities. The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security’s investment value. Convertible securities rank senior to common stock in a corporation’s capital structure but are usually subordinated to comparable nonconvertible securities. Convertible securities may be subject to redemption at the option of the issuer at a price established in the convertible security’s governing instrument. ADDITIONAL INVESTMENT POLICIES In addition to holding the portfolio investments described above, the Fund may, but is not required to, use the following investment practices: Strategic Transactions. The Fund may, but is not required to, use various investment strategies as described below (“Strategic Transactions”). Strategic Transactions may be used for a variety of purposes including hedging, risk management, portfolio management or to earn income. Any or all of the investment techniques described herein may be used at any time and there is no particular strategy that dictates the use of one technique rather than another, as the use of any Strategic Transaction by the Fund is a function of numerous variables including market conditions. The Fund complies with applicable regulatory requirements when implementing Strategic Transactions, including the Derivatives Rule. Although the Investment Adviser seeks to use Strategic Transactions to further the Fund’s investment objective, no assurance can be given that the use of Strategic Transactions will achieve this result. General Risks of Derivatives Strategic Transactions may involve the purchase and sale of derivative instruments. A derivative is a financial instrument the value of which depends upon (or derives from) the value of another asset, security, interest rate, or index. Derivatives may relate to a wide variety of underlying instruments, including equity and debt securities, indexes, interest rates, currencies and other assets. Certain derivative instruments which the Fund may use and the risks of those instruments are described in further detail below. The Fund may in the future also utilize derivatives techniques, instruments and strategies that may be newly developed or permitted as a result of regulatory changes, consistent with the Fund’s investment objective and policies. Such newly developed techniques, instruments and strategies may involve risks different than or in addition to those described herein. No assurance can be given that any derivatives strategy employed by the Fund will be successful. The risks associated with the use of derivatives are different from, and possibly greater than, the risks associated with investing directly in the instruments underlying such derivatives. Derivatives are highly specialized instruments that require investment techniques and risk analyses different from other portfolio investments. The use of derivative instruments requires an understanding not only of the underlying instrument but also of the derivative itself. Certain risk factors generally applicable to derivative transactions are described below. ● Derivatives are subject to the risk that the market value of the derivative itself or the market value of underlying instruments will change in a way adverse to the Fund’s interests. The Fund bears the risk that the Investment Adviser may incorrectly forecast future market trends and other financial or economic factors or the value of the underlying security, index, interest rate or currency when establishing a derivatives position for the Fund. ● Derivatives may be subject to pricing or “basis” risk, which exists when a derivative becomes extraordinarily expensive (or inexpensive) relative to historical prices or corresponding instruments. Under such market conditions, it may not be economically feasible to initiate a transaction or liquidate a position at an advantageous time or price. ● Many derivatives are complex and often valued subjectively. Improper valuations can result in increased payment requirements to counterparties or a loss of value to the Fund. ● Using derivatives as a hedge against a portfolio investment presents the risk that the derivative will have imperfect correlation with the portfolio investment, which could result in the Fund incurring substantial losses. This correlation risk may be greater in the case of derivatives based on an index or other basket of securities, as the portfolio securities being hedged may not duplicate the components of the underlying index or the basket may not be of exactly the same type of obligation as those underlying the derivative. The use of derivatives for “cross hedging” purposes (using a derivative based on one instrument as a hedge on a different instrument) may also involve greater correlation risks. ● While using derivatives for hedging purposes can reduce the Fund’s risk of loss, it may also limit the Fund’s opportunity for gains or result in losses by offsetting or limiting the Fund’s ability to participate in favorable price movements in portfolio investments. ● Derivatives transactions for non-hedging purposes involve greater risks and may result in losses which would not be offset by increases in the value of portfolio securities or declines in the cost of securities to be acquired. In the event that the Fund enters into a derivatives transaction as an alternative to purchasing or selling the underlying instrument or in order to obtain desired exposure to an index or market, the Fund will be exposed to the same risks as are incurred in purchasing or selling the underlying instruments directly. ● The use of certain derivatives transactions involves the risk of loss resulting from the insolvency or bankruptcy of the other party to the contract (the “counterparty”) or the failure by the counterparty to make required payments or otherwise comply with the terms of the contract. In the event of default by a counterparty, the Fund may have contractual remedies pursuant to the agreements related to the transaction. ● Liquidity risk exists when a particular derivative is difficult to purchase or sell. If a derivative transaction is particularly large or if the relevant market is illiquid, the Fund may be unable to initiate a transaction or liquidate a position at an advantageous time or price. ● Certain derivatives transactions, including over-the-counter (“OTC”) options, swaps, forward contracts, certain options on foreign currencies and other OTC derivatives, are not entered into or traded on exchanges or in markets regulated by the U.S. Commodity Futures Trading Commission (“CFTC”) or the SEC. Instead, such OTC derivatives are entered into directly by the counterparties and may be traded only through financial institutions acting as market makers. OTC derivatives transactions can only be entered into with a willing counterparty. Where no such counterparty is available, the Fund will be unable to enter into a desired transaction. There also may be greater risk that no liquid secondary market in the trading of OTC derivatives will exist, in which case the Fund may be required to hold such instruments until exercise, expiration or maturity. Many of the protections afforded to exchange participants will not be available to participants in OTC derivatives transactions. OTC derivatives transactions are not subject to the guarantee of an exchange or clearinghouse and as a result the Fund would bear greater risk of default by the counterparties to such transactions. ● The Fund may be required to make physical delivery of portfolio securities underlying a derivative in order to close out a derivatives position or to sell portfolio securities at a time or price at which it may be disadvantageous to do so in order to obtain cash to close out or to maintain a derivatives position. ● As a result of the structure of certain derivatives, adverse changes in the value of the underlying instrument can result in a losses substantially greater than the amount invested in the derivative itself. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. ● Certain derivatives, including certain OTC options and swap agreements, may be considered illiquid. ● Certain derivative transactions may give rise to a form of leverage. Leverage associated with derivative transactions may cause the Fund to sell portfolio securities when it may not be advantageous to do so to satisfy its obligations or may cause the Fund to be more volatile than if the Fund had not been leveraged. ● Derivatives transactions conducted outside the United States may not be conducted in the same manner as those entered into on U.S. exchanges, and may be subject to different margin, exercise, settlement or expiration procedures. Many of the risks of OTC derivatives transactions are also applicable to derivatives transactions conducted outside the United States. Derivatives transactions conducted outside the United States are subject to the risk of governmental action affecting the trading in, or the prices of, foreign securities, currencies and other instruments The value of such positions could be adversely affected by foreign political and economic factors; lesser availability of data on which to make trading decisions; delays the Fund’s ability to act upon economic events occurring in foreign markets; and less liquidity than U.S. markets. ● Currency derivatives are subject to additional risks. Currency derivatives transactions may be negatively affected by government exchange controls, blockages, and manipulations. Currency exchange rates may be influenced by factors extrinsic to a country’s economy. There is no systematic reporting of last sale information with respect to foreign currencies. As a result, the available information on which trading in currency derivatives will be based may not be as complete as comparable data for other transactions. Events could occur in the foreign currency market which will not be reflected in currency derivatives until the following day, making it more difficult for the Fund to respond to such events in a timely manner. ● Legislation regarding regulation of the financial sector, including the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”), which was signed into law in July 2010, will change the way in which certain derivative instruments are regulated and/or traded. Such regulation may impact the availability, liquidity and cost of derivative instruments. While many provisions of the Dodd-Frank Act must be implemented through future rulemaking, and any regulatory or legislative activity may not necessarily have a direct, immediate effect upon the Fund, it is possible that, upon implementation of these measures or any future measures, they could potentially limit or completely restrict the ability of the Fund to use certain derivative instruments as a part of its investment strategy, increase the costs of using these instruments or make them less effective. Limits or restrictions applicable to the counterparties with which the Fund engages in derivatives transactions could also prevent the Fund from using these instruments or affect the pricing or other factors relating to these instruments, or may change the availability of certain investments. The Financial CHOICE Act, which was passed by the U.S. House of Representatives in June 2017, would, if enacted, roll back parts of the Dodd-Frank Act. There can be no assurance that such legislation or regulation will not have a material adverse effect on the Fund or will not impair the ability of the Fund to utilize certain derivatives transactions or achieve its investment objective. ● The Investment Adviser has claimed an exclusion from the definition of the term “commodity pool operator” under the Commodity Exchange Act pursuant to CFTC Rule 4.5. Accordingly, the Investment Adviser is currently not subject to registration or regulation as a commodity pool operator under the Commodity Exchange Act with respect to the Fund. If the Investment Adviser was unable to claim the exclusion with respect to the Fund, the Investment Adviser would become subject to registration and regulation as a commodity pool operator, which would subject the Investment Adviser and the Fund to additional registration and regulatory requirements and increased operating expenses. The Fund intends to limit its investments such that the Investment Adviser may continue to claim the exclusion with respect to the Fund, which may limit the Fund’s ability to use certain Strategic Transactions, including futures, options on futures and swaps. Options An option is a contract that gives the holder of the option the right, but not the obligation, to buy from (in the case of a call option) or sell to (in the case of a put option) the seller of the option (the “option writer”) the underlying security at a specified fixed price (the “exercise price”) prior to a specified date (the “expiration date”). The buyer of the option pays to the option writer the option premium, which represents the purchase price of the option. Exchange-traded options are issued by a regulated intermediary such as the Options Clearing Corporation (“OCC”), which guarantees the performance of the obligations of the parties to such option. OTC options are purchased from or sold to counterparties through direct bilateral agreement between the counterparties. Certain options, such as options on individual securities, are settled through physical delivery of the underlying security, whereas other options, such as index options, are settled in cash in an amount based on the value of the underlying instrument multiplied by a specified multiplier. Writing Options The Fund may write call options that are “covered.” A call option on a security is covered if (a) the Fund owns the security underlying the call or has an absolute and immediate right to acquire that security without additional cash consideration upon conversion or exchange of other securities held by the Fund; or (b) the Fund has purchased a call on the underlying security, the exercise price of which is equal to or less than the exercise price of the call written. Selling call options involves the risk that the Fund may be required to sell the underlying security at a disadvantageous price, below the market price of such security, at the time the option is exercised. As the writer of a covered call option, the Fund gives up the opportunity during the option’s life to profit from increases in the market value of the security covering the call option above the sum of the premium and the strike price of the call, but the Fund retains the risk of loss should the price of the underlying security decline. The Fund may also write uncovered call options (i.e., where the Fund does not own the underlying security or index). Similar to a naked short sale, writing an uncovered call creates the risk of an unlimited loss, in that the price of the underlying security could theoretically increase without limit, thus increasing the cost of buying those securities to cover the call option if it is exercised before it expires. There can be no assurance that the securities necessary to cover the call opti | |||||||||||||
| Risk Factors [Table Text Block] | RISKS Investment and Market Risk An investment in common shares of the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest. An investment in the common shares of the Fund represents an indirect investment in the securities owned by the Fund. The value of those securities may fluctuate, sometimes rapidly and unpredictably, particularly under current economic, financial, labor, and health conditions. The value of the securities owned by the Fund may decline due to general market conditions that are not specifically related to a particular issuer, such as real or perceived economic conditions, changes in interest or currency rates or changes in investor sentiment or market outlook generally. At any point in time, your common shares may be worth less than your original investment, including the reinvestment of Fund dividends and distributions. Common Stock Risk The Fund will have exposure to common stocks. Although common stocks have historically generated higher average total returns than fixed-income securities over the long-term, common stocks also have experienced significantly more volatility in those returns and may significantly under-perform relative to fixed income securities during certain periods. An adverse event, such as an unfavorable earnings report, may depress the value of a particular common stock held by the Fund. Also, the price of common stocks is sensitive to general movements in the stock market and a drop in the stock market may depress the price of common stocks to which the Fund has exposure. Common stock prices fluctuate for several reasons, including changes in investors’ perceptions of the financial condition of an issuer or the general condition of the relevant stock market, or when political or economic events affecting the issuers occur. In addition, common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase. At times, stock markets can be volatile and stock prices can change substantially. While broad market measures of common stocks have historically generated higher average returns than income securities, common stocks have also experienced significantly more volatility in those returns. Common stock in which the Fund invests is structurally subordinated to preferred stock, bonds and other debt instruments in a company’s capital structure in terms of priority to corporate income and are therefore inherently more risky than preferred stock or debt instruments of such issuers. Concentration Risk The Fund’s investments will be concentrated in issuers in the industry or group of industries that make up the natural resources sector. The Fund has adopted a fundamental investment restriction to invest at least 25% of its total assets in natural resources companies. In addition, in accordance with the Fund’s 80% policy, the Fund invests at least 80% of its net assets plus borrowings for investment purposes in midstream energy investments. Midstream energy companies are a specific type of natural resources company. Because the Fund will be concentrated, it may be subject to more risks than if it were more broadly diversified over numerous industries and sectors of the economy. General changes in market sentiment towards companies in the natural resources sector, or midstream energy companies specifically, may adversely affect the Fund, and the performance of the natural resources sector, or midstream energy companies specifically, may lag behind the broader market as a whole. Also, the Fund’s concentration in the natural resources sector, and midstream energy companies specifically, may subject the Fund to a variety of risks associated with that sector. See “Additional Information (Unaudited)—Risks—Midstream Energy Company Risks.” Midstream Energy Company Risks Midstream energy companies are subject to certain risks, including, but not limited to, the following: Commodity Price Risk . Midstream energy companies may be affected by fluctuations in the prices of commodities, including, for example, natural gas, natural gas liquids and crude oil, in the short- and long-term. Natural resources commodity prices have been very volatile in the past and such volatility is expected to continue. Fluctuations in commodity prices can result from changes in general economic conditions or political circumstances (especially of key energy-consuming countries); market conditions; weather patterns; domestic production levels; volume of imports; energy conservation; domestic and foreign governmental regulation; international politics; policies of the Organization of Petroleum Exporting Countries (“OPEC”); taxation; tariffs; and the availability and costs of local, intrastate and interstate transportation methods. Midstream energy companies engaged in crude oil and natural gas exploration, development or production, natural gas gathering and processing, crude oil refining and transportation and coal mining or sales may be directly affected by their respective natural resources commodity prices. The volatility of, and interrelationships between, commodity prices can also indirectly affect certain other midstream energy companies due to the potential impact on the volume of commodities transported, processed, stored or distributed. Some midstream energy companies that own the underlying energy commodity may be unable to effectively mitigate or manage direct margin exposure to commodity price levels. The natural resources sector as a whole may also be impacted by the perception that the performance of natural resources sector companies is directly linked to commodity prices. The prices of companies’ securities can be adversely affected by market perceptions that their performance and distributions or distributions are directly tied to commodity prices. High commodity prices may drive further energy conservation efforts and a slowing economy may adversely impact energy consumption which may adversely affect the performance of midstream energy companies. Prices of oil and other energy commodities have experienced significant volatility during recent years, including as a result of the pandemic spread of infectious respiratory illness caused by a novel coronavirus known as “COVID-19,” during which demand for energy commodities fell sharply and energy commodity prices reached historic lows, and may continue to experience relatively high volatility for a prolonged period. Companies engaged in crude oil and natural gas exploration, development or production, natural gas gathering and processing, crude oil refining and transportation and coal mining or sales may be directly affected by their respective natural resources commodity prices. The volatility of commodity prices may also indirectly affect certain companies engaged in the transportation, processing, storage or distribution of such commodities. Some companies that own the underlying commodities may be unable to effectively mitigate or manage direct margin exposure to commodity price levels. The natural resources sector as a whole may also be impacted by the perception that the performance of natural resources sector companies is directly linked to commodity prices. As a result, many companies in which the Fund invests may have been and may continue to be adversely impacted by volatility of prices of energy commodities. Reductions in production of oil and other energy commodities may lag decreases in demand or declines in commodity prices, resulting in global oversupply in such commodities. Slower global growth may lower demand for oil and other energy commodities and increased exports by Iran with the end of sanctions may increase supply, exacerbating oversupply of such commodities and further reducing commodity prices. Continued volatility of commodity prices could further erode such companies’ growth prospects and negatively impact such companies’ ability to sustain attractive distribution levels. Cyclicality Risk. The operating results of companies in the broader natural resources sector are cyclical, with fluctuations in commodity prices and demand for commodities driven by a variety of factors. The highly cyclical nature of the natural resources sector may adversely affect the earnings or operating cash flows of the midstream energy companies in which the Fund invests. Supply Risk. The profitability of midstream energy companies, particularly those involved in processing, gathering and pipeline transportation, may be materially impacted by the volume of natural gas or other energy commodities available for transportation, processing, storage or distribution. A significant decrease in the production of natural gas, crude oil, coal or other energy commodities, due to the decline of production from existing resources, import supply disruption, depressed commodity prices or otherwise, would reduce the revenue, operating income and operating cash flows of midstream energy companies and, therefore, their ability to make distributions or pay dividends. The volume of production of energy commodities and the volume of energy commodities available for transportation, storage, processing or distribution could be affected by a variety of factors, including depletion of resources; depressed commodity prices; catastrophic events; labor relations; increased environmental or other governmental regulation; equipment malfunctions and maintenance difficulties; import volumes; international politics; policies of OPEC; and increased competition from alternative energy sources. Demand Risk. A sustained decline in demand for coal, natural gas, natural gas liquids, crude oil and refined petroleum products could adversely affect a midstream energy company’s revenues and cash flows. Factors that could lead to a sustained decrease in market demand include a recession or other adverse economic conditions, an increase in the market price of the underlying commodity that is not, or is not expected to be, merely a short-term increase, higher taxes or other regulatory actions that increase costs, or a shift in consumer demand for such products. Demand may also be adversely affected by consumer sentiment with respect to global warming and by state or federal legislation intended to promote the use of alternative energy sources. Depletion Risk . Companies engaged in the exploration, development, management or production of energy commodities face the risk that commodity reserves are depleted over time. Such companies seek to increase their reserves through expansion of their current businesses, acquisitions, further development of their existing sources of energy commodities, exploration of new sources of energy commodities or by entering into long-term contracts for additional reserves; however, there are risks associated with each of these potential strategies. If such companies fail to acquire additional reserves in a cost-effective manner and at a rate at least equal to the rate at which their existing reserves decline, their financial performance may suffer. Additionally, failure to replenish reserves could reduce the amount and affect the tax characterization of the distributions paid by such companies. Risks Related to Expansions and Acquisitions. Midstream energy companies employ a variety of means to increase cash flow, including increasing utilization of existing facilities, expanding operations through new construction or development activities, expanding operations through acquisitions, or securing additional long-term contracts. Thus, some midstream energy companies may be subject to construction risk, development risk, acquisition risk or other risks arising from their specific business strategies. Midstream energy companies that attempt to grow through acquisitions may not be able to effectively integrate acquired operations with their existing operations. In addition, acquisition or expansion projects may not perform as anticipated. A significant slowdown in merger and acquisition activity in the natural resources sector could reduce the growth rate of cash flows received by the Fund from midstream energy companies that grow through acquisitions. Competition Risk. The natural resources sector is highly competitive. The midstream energy companies in which the Fund invests face substantial competition from other companies, many of which will have greater financial, technological, human and other resources, in acquiring natural resources assets, obtaining and retaining customers and contracts and hiring and retaining qualified personnel. Larger companies may be able to pay more for assets and may have a greater ability to continue their operations during periods of low commodity prices. To the extent that the midstream energy companies in which the Fund invests are unable to compete effectively, their operating results, financial position, growth potential and cash flows may be adversely affected, which could in turn adversely affect the results of the Fund. Weather Risk. Extreme weather conditions could result in substantial damage to the facilities of certain midstream energy companies located in the affected areas and significant volatility in the supply of natural resources, commodity prices and the earnings of midstream energy companies and could therefore adversely affect their securities. Interest Rate Risk. The prices of the equity and debt securities of the midstream energy companies the Fund expects to hold in its portfolio are susceptible in the short-term to a decline when interest rates rise. Rising interest rates could limit the capital appreciation of securities of certain midstream energy companies as a result of the increased availability of alternative investments with comparable yields. Rising interest rates could adversely impact the financial performance of midstream energy companies by increasing their cost of capital. This may reduce their ability to execute acquisitions or expansion projects in a cost-effective manner. The risk of interest rates rising is more pronounced in the current market environment because of recent monetary policy measures and the low interest rate environment in recent years. Business Segment Specific Risk. Midstream energy companies are also subject to risks that are specific to the particular business segment of the natural resources sector in which they operate. Pipelines. Pipeline companies are subject to the demand for natural gas, natural gas liquids, crude oil or refined products in the markets they serve, changes in the availability of products for gathering, transportation, processing or sale due to natural declines in reserves and production in the supply areas serviced by the companies’ facilities, sharp decreases in crude oil or natural gas prices that cause producers to curtail production or reduce capital spending for exploration activities, and environmental regulation. Demand for gasoline, which accounts for a substantial portion of refined product transportation, depends on price, prevailing economic conditions in the markets served, and demographic and seasonal factors. Companies that own interstate pipelines that transport natural gas, natural gas liquids, crude oil or refined petroleum products are subject to regulation by FERC with respect to the tariff rates they may charge for transportation services. An adverse determination by FERC with respect to the tariff rates of such a company could have a material adverse effect on its business, financial condition, results of operations and cash flows of those companies and their ability to pay cash distributions or dividends. In addition, FERC has a tax allowance policy, which permits such companies to include in their cost of service an income tax allowance to the extent that their owners have an actual or potential tax liability on the income generated by them. If FERC’s income tax allowance policy were to change in the future to disallow a material portion of the income tax allowance taken by such interstate pipeline companies, it would adversely impact the maximum tariff rates that such companies are permitted to charge for their transportation services, which would in turn adversely affect the results of operations and cash flows of those companies and their ability to pay cash distributions or dividends to their unit holders or shareholders. Gathering and Processing. Gathering and processing companies are subject to natural declines in the production of oil and natural gas fields, which utilize their gathering and processing facilities as a way to market their production, prolonged declines in the price of natural gas or crude oil, which curtails drilling activity and therefore production and declines in the prices of natural gas liquids and refined petroleum products, which cause lower processing margins. In addition, some gathering, and processing contracts subject the gathering or processing company to direct commodities price risk. Exploration and Production. Exploration, development and production companies are particularly vulnerable to declines in the demand for and prices of crude oil and natural gas. Reductions in prices for crude oil and natural gas can cause a given reservoir to become uneconomic for continued production earlier than it would if prices were higher, resulting in the plugging and abandonment of, and cessation of production from, that reservoir. In addition, lower commodity prices not only reduce revenues but also can result in substantial downward adjustments in reserve estimates. The accuracy of any reserve estimate is a function of the quality of available data, the accuracy of assumptions regarding future commodity prices and future exploration and development costs and engineering and geological interpretations and judgments. Different reserve engineers may make different estimates of reserve quantities and related revenue based on the same data. Actual oil and gas prices, development expenditures and operating expenses will vary from those assumed in reserve estimates, and these variances may be significant. Any significant variance from the assumptions used could result in the actual quantity of reserves and future net cash flow being materially different from those estimated in reserve reports. In addition, results of drilling, testing and production and changes in prices after the date of reserve estimates may result in downward revisions to such estimates. Substantial downward adjustments in reserve estimates could have a material adverse effect on a given exploration and production company’s financial position and results of operations. In addition, due to natural declines in reserves and production, exploration and production companies must economically find or acquire and develop additional reserves in order to maintain and grow their revenues and distributions. Propane. Propane companies are subject to earnings variability based upon weather patterns in the locations where they operate and increases in the wholesale price of propane which reduce profit margins. In addition, propane companies are facing increased competition due to the growing availability of natural gas, fuel oil and alternative energy sources for residential heating. Coal. Coal companies are subject to declines in the demand for and prices of coal. Demand variability can be based on weather conditions, the strength of the domestic economy, the level of coal stockpiles in their customer base, and the prices of competing sources of fuel for electric generation. They are also subject to supply variability based on geological conditions that reduce the productivity of mining operations, the availability of regulatory permits for mining activities and the availability of coal that meets the standards of the federal Clean Air Act of 1990, as amended (the “Clean Air Act”). Demand and prices for coal may also be affected by current and proposed regulatory limitations on emissions from coal-fired power plants and the facilities of other coal end users. Such limitations may reduce demand for the coal produced and transported by coal companies. Certain coal companies could face declining revenues if they are unable to acquire additional coal reserves or other mineral reserves that are economically recoverable. Marine Shipping . Marine shipping companies are subject to supply of and demand for, and level of consumption of, natural gas, liquefied natural gas, crude oil, refined petroleum products and liquefied petroleum gases in the supply areas and market areas they serve, which affect the demand for marine shipping services and therefore charter rates. Shipping companies’ vessels and cargoes are also subject to the risk of being damaged or lost due to marine disasters, extreme weather, mechanical failures, grounding, fire, explosions, collisions, human error, piracy, war and terrorism. Some vessels may also require replacement or significant capital improvements earlier than otherwise required due to changing regulatory standards. Shipping companies or their ships may be chartered in any country and the Fund’s investments in such issuers may be subject to risks similar to risks related to investments in non-U.S. securities. Cash Flow Risk. The Fund will derive substantially all of its cash flow from investments in equity securities of midstream energy companies. The amount of cash that the Fund has available to distribute to shareholders will depend on the ability of the midstream energy companies in which the Fund has an interest to make distributions or pay dividends to their investors and the tax character of those distributions or dividends. The Fund will likely have no influence over the actions of the companies in which it invests with respect to the payment of distributions or dividends. The amount of cash that any individual midstream energy company can distribute to its investors, including the Fund, will depend on the amount of cash it generates from operations, which will vary from quarter to quarter depending on factors affecting the natural resources sector generally and the particular business lines of the issuer. Available cash will also depend on the midstream energy company’s operating costs, capital expenditures, debt service requirements, acquisition costs (if any), fluctuations in working capital needs and other factors. With respect to the Fund’s investments in MLPs, the cash that an MLP will have available for distribution will also depend on the incentive distributions payable to its general partner or managing member in connection with distributions paid to its equity investors. Regulatory Risk . The profitability of midstream energy companies could be adversely affected by changes in the regulatory environment. Midstream energy companies are subject to significant foreign, federal, state and local regulation in virtually every aspect of their operations, including with respect to how facilities are constructed, maintained and operated, environmental and safety controls, and the prices they may charge for the products and services they provide. Such regulation can change over time in both scope and intensity. For example, a particular by-product may be declared hazardous by a regulatory agency and unexpectedly increase production costs. Various governmental authorities have the power to enforce compliance with these regulations and the permits issued under them, and violators are subject to administrative, civil and criminal penalties, including civil fines, injunctions or both. Stricter laws, regulations or enforcement policies could be enacted in the future which would likely increase compliance costs and may adversely affect the financial performance of midstream energy companies. Midstream energy companies may be adversely affected by future regulatory requirements. While the nature of such regulations cannot be predicted at this time, they may impose additional costs or limit certain operations by midstream energy companies. Specifically, the operations of wells, gathering systems, pipelines, refineries and other facilities are subject to stringent and complex federal, state and local environmental laws and regulations. These include, for example: ● the federal Clean Air Act and comparable state laws and regulations that impose obligations related to air emissions. ● the federal Clean Water Act and comparable state laws and regulations that impose obligations related to discharges of pollutants into regulated bodies of water. ● the federal Resource Conservation and Recovery Act (“RCRA”) and comparable state laws and regulations that impose requirements for the handling and disposal of waste from facilities; and ● the federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 (“CERCLA”), also known as “Superfund,” and comparable state laws and regulations that regulate the cleanup of hazardous substances that may have been released at properties currently or previously owned or operated by midstream energy companies or at locations to which they have sent waste for disposal. Failure to comply with these laws and regulations may trigger a variety of administrative, civil and criminal enforcement measures, including the assessment of monetary penalties, the imposition of remedial requirements, and the issuance of orders enjoining future operations. Certain environmental statutes, including RCRA, CERCLA, the federal Oil Pollution Act and analogous state laws and regulations, impose strict, joint and several liability for costs required to clean up and restore sites where hazardous substances have been disposed or otherwise released. Moreover, it is not uncommon for neighboring landowners and other third parties to file claims for personal injury and property damage allegedly caused by the release of hazardous substances or other waste products into the environment. There is an inherent risk that midstream energy companies may incur environmental costs and liabilities due to the nature of their businesses and the substances they handle. For example, an accidental release from wells or gathering pipelines could subject them to substantial liabilities for environmental cleanup and restoration costs, claims made by neighboring landowners and other third parties for personal injury and property damage, and fines or penalties for related violations of environmental laws or regulations. Moreover, the possibility exists that stricter laws, regulations or enforcement policies could significantly increase the compliance costs of midstream energy companies, and the cost of any remediation that may become necessary. Midstream energy companies may not be able to recover these costs from insurance. Proposals for voluntary initiatives and mandatory controls are being discussed both in the United States and worldwide to reduce emissions of “greenhouse gases” such as carbon dioxide, a by-product of burning fossil fuels, and methane, the major constituent of natural gas, which many scientists and policymakers believe contribute to global climate change. These measures, if adopted, could result in increased costs to certain companies in which the Fund invests to operate and maintain natural resources facilities and administer and manage a greenhouse gas emissions program. In the wake of a Supreme Court decision holding that the EPA has some legal authority to deal with climate change under the Clean Air Act, the federal government announced on May 14, 2007 that the EPA and the Departments of Transportation, Energy, and Agriculture would jointly write regulations to cut gasoline use and control greenhouse gas emissions from cars and trucks. These measures if adopted could reduce demand for energy or raise prices, which may adversely affect the total return of certain of the Fund’s investments. Environmental Risk . There is an inherent risk that midstream energy companies may incur environmental costs and liabilities due to the nature of their businesses and the substances they handle. For example, an accidental release from wells or gathering pipelines could subject them to substantial liabilities for environmental cleanup and restoration costs, claims made by neighboring landowners and other third parties for personal injury and property damage, and fines or penalties for related violations of environmental laws or regulations. Moreover, the possibility exists that stricter laws, regulations or enforcement policies could significantly increase the compliance costs of midstream energy companies, and the cost of any remediation that may become necessary. Midstream energy companies may not be able to recover these costs from insurance. In the wake of a Supreme Court decision holding that the EPA has some legal authority to deal with climate change under the Clean Air Act, the EPA and the Department of Transportation jointly wrote regulations to cut gasoline use and control greenhouse gas emissions from cars and trucks. These measures, and other programs addressing greenhouse gas emissions, could reduce demand for energy or raise prices, which may adversely affect the total return of certain of the Fund’s investments. The types of regulations described above can change over time in both scope and intensity, may have adverse effects on midstream energy companies and may be implemented in unforeseen manners on an “emergency” basis in response to catastrophes or other events. Affiliated Party Risk . Certain midstream energy companies are dependent on their parents or sponsors for a majority of their revenues. Any failure by a midstream energy company’s parents or sponsors to satisfy their payments or obligations would impact the midstream energy company’s revenues and cash flows and ability to make distributions. Moreover, the terms of a midstream energy company’s transactions with its parent or sponsor are typically not arrived at on an arm’s-length basis and may not be as favorable to the midstream energy company as a transaction with a non-affiliate. Catastrophe Risk . The operations of midstream energy companies are subject to many hazards inherent in the exploration for, and development, production, gathering, transportation, processing, storage, refining, distribution, mining or marketing of, coal, natural gas, natural gas liquids, crude oil, refined petroleum products or other hydrocarbons, including: damage to production equipment, pipelines, storage tanks or related equipment and surrounding properties or other adverse impacts resulting from hurricanes, tornadoes, floods, fires, climate conditions, extreme weather events and other natural disasters and the responses thereto or acts of terrorism; inadvertent damage from construction or other equipment; leaks of natural gas, natural gas liquids, crude oil, refined petroleum products or other hydrocarbons; and fires and explosions. Since the September 11th terrorist attacks, the U.S. government has issued warnings that energy assets, specifically U.S. pipeline infrastructure, may be targeted in future terrorist attacks. These dangers give rise to risks of substantial losses as a result of loss or destruction of commodity reserves; damage to or destruction of property, facilities and equipment; pollution and environmental damage; and personal injury or loss of life. Any occurrence of such catastrophic events could bring about a limitation, suspension or discontinuation of the operations of midstream energy companies. Midstream energy companies may not be fully insured against all risks inherent in their business operations and therefore accidents and catastrophic events could adversely affect such companies’ operations, financial conditions and ability to pay distributions to shareholders. Legislation Risk . There have been proposals in Congress to eliminate certain tax incentives widely used by oil and gas companies and to impose new fees on certain energy producers. The elimination of such tax incentives and imposition of such fees could adversely affect the natural sector generally or specific midstream energy companies in which the Fund invests. Technology Risk . Some midstream energy companies are focused on developing new technologies and are strongly influenced by technological changes. Technology development efforts by midstream energy companies may not result in viable methods or products. Midstream energy companies may bear high research and development costs, which can limit their ability to maintain operations during periods of organizational growth or instability. Some midstream energy companies may be in the early stages of operations and may have limited | |||||||||||||
| Effects of Leverage [Text Block] | Effects of Leverage As of November 30, 2023, the Fund had outstanding Indebtedness of approximately $19.315 million, which represented 19% of the Fund’s Managed Assets (or approximately 23% of its net assets attributable to the Fund’s Common Shares). The interest rate charged on such Indebtedness as of November 30, 2023 was 6.46%. Assuming that the Fund’s leverage costs remain as described above, then the incremental income generated by the Fund’s portfolio (net of estimated expenses including expenses related to the leverage) must exceed approximately 1.16% to cover such interest specifically related to the borrowing. These numbers are merely estimates used for illustration. Actual interest rates may vary frequently and in the future may be significantly higher or lower than the rate estimated above. The following table is designed to assist the investor in understanding the effects of leverage by illustrating the effect on the return to a holder of the Fund’s Common Shares of leverage in the amount of approximately 331/3% of the Fund’s Managed Assets (i.e., 50% of its net assets attributable to the Fund’s Common Shares), assuming hypothetical annual returns of the Fund’s portfolio of minus 10% to plus 10%. As the table shows, leverage generally increases the return to holders of Common Shares when portfolio return is positive and greater than the cost of leverage and decreases the return when the portfolio return is negative or less than the cost of leverage. The figures appearing in the table are hypothetical and actual returns may be greater or less than those appearing in the table. Assumed portfolio total return (net of expenses) (10.00)% (5.00)% 0.00% 5.00% 10.00% Common Share total return (14.80)% (8.13)% (1.46)% 5.20% 11.87% Common Share total return is composed of two elements: distributions on Common Shares paid by the Fund (the amount of which is largely determined by the Fund’s net investment income after paying distributions or interest on its outstanding leverage) and gains or losses on the value of the securities the Fund owns. As required by SEC rules, the table above assumes that the Fund is more likely to suffer capital losses than to enjoy capital appreciation. For example, to assume a total return of 0%, the Fund must assume that the distributions it receives on its investments are entirely offset by losses in the value of those securities. During the time in which the Fund is utilizing leverage, the amount of the fees paid to the Investment Adviser for investment advisory services will be higher than if the Fund did not utilize such leverage because the fees paid will be calculated based on the Fund’s Managed Assets, which may create a conflict of interest between the Investment Adviser and the Common Shareholders. Because the Fund’s leverage costs will be borne by the Fund at a specified rate, only the Fund’s Common Shareholders will bear the cost associated with such leverage. | |||||||||||||
| Effects of Leverage [Table Text Block] | Assumed portfolio total return (net of expenses) (10.00)% (5.00)% 0.00% 5.00% 10.00% Common Share total return (14.80)% (8.13)% (1.46)% 5.20% 11.87% | |||||||||||||
| Effects of Leverage, Purpose [Text Block] | The following table is designed to assist the investor in understanding the effects of leverage by illustrating the effect on the return to a holder of the Fund’s Common Shares of leverage in the amount of approximately 331/3% of the Fund’s Managed Assets (i.e., 50% of its net assets attributable to the Fund’s Common Shares), assuming hypothetical annual returns of the Fund’s portfolio of minus 10% to plus 10%. As the table shows, leverage generally increases the return to holders of Common Shares when portfolio return is positive and greater than the cost of leverage and decreases the return when the portfolio return is negative or less than the cost of leverage. The figures appearing in the table are hypothetical and actual returns may be greater or less than those appearing in the table. | |||||||||||||
| Share Price [Table Text Block] | Market Price Corresponding Corresponding Fiscal Quarter Ended High Low High Low High Low November 30, 2023 $ 43.76 $ 34.30 $ 39.34 $ 35.58 11.24 % -3.60 % August 31, 2023 $ 43.15 $ 34.41 $ 39.75 $ 35.58 8.55 % -3.29 % May 31, 2023 $ 35.00 $ 30.17 $ 40.08 $ 34.92 -12.67 % -13.60 % February 28, 2023 $ 36.71 $ 32.27 $ 41.07 $ 38.00 -10.62 % -15.08 % November 30, 2022 $ 37.81 $ 30.80 $ 43.93 $ 34.86 -13.93 % -11.65 % August 31, 2022 $ 36.23 $ 27.03 $ 46.57 $ 34.73 -22.20 % -22.17 % May 31, 2022 $ 36.19 $ 30.76 $ 44.87 $ 39.24 -19.34 % -21.61 % February 28, 2022 $ 33.98 $ 29.13 $ 38.74 $ 34.64 -12.29 % -15.91 % November 30, 2021 $ 35.90 $ 27.89 $ 41.82 $ 36.53 -14.16 % -23.65 % August 31, 2021 $ 31.59 $ 25.87 $ 41.41 $ 34.18 -23.73 % -24.31 % May 31, 2021 $ 28.92 $ 22.73 $ 37.34 $ 31.07 -22.55 % -26.84 % February 28, 2021 $ 25.12 $ 20.84 $ 33.36 $ 27.41 -24.70 % -23.97 % | |||||||||||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||||||||||
| Outstanding Securities [Table Text Block] | The following information regarding the Fund’s authorized shares is as of November 30, 2023: Title of Class Amount Authorized Amount Held Amount Common Shares of Beneficial Interest Unlimited None 2,184,950 | |||||||||||||
| Document Period End Date | Nov. 30, 2023 | |||||||||||||
| Investment and Market Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Investment and Market Risk An investment in common shares of the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest. An investment in the common shares of the Fund represents an indirect investment in the securities owned by the Fund. The value of those securities may fluctuate, sometimes rapidly and unpredictably, particularly under current economic, financial, labor, and health conditions. The value of the securities owned by the Fund may decline due to general market conditions that are not specifically related to a particular issuer, such as real or perceived economic conditions, changes in interest or currency rates or changes in investor sentiment or market outlook generally. At any point in time, your common shares may be worth less than your original investment, including the reinvestment of Fund dividends and distributions. | |||||||||||||
| Common Stock Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Common Stock Risk The Fund will have exposure to common stocks. Although common stocks have historically generated higher average total returns than fixed-income securities over the long-term, common stocks also have experienced significantly more volatility in those returns and may significantly under-perform relative to fixed income securities during certain periods. An adverse event, such as an unfavorable earnings report, may depress the value of a particular common stock held by the Fund. Also, the price of common stocks is sensitive to general movements in the stock market and a drop in the stock market may depress the price of common stocks to which the Fund has exposure. Common stock prices fluctuate for several reasons, including changes in investors’ perceptions of the financial condition of an issuer or the general condition of the relevant stock market, or when political or economic events affecting the issuers occur. In addition, common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase. At times, stock markets can be volatile and stock prices can change substantially. While broad market measures of common stocks have historically generated higher average returns than income securities, common stocks have also experienced significantly more volatility in those returns. Common stock in which the Fund invests is structurally subordinated to preferred stock, bonds and other debt instruments in a company’s capital structure in terms of priority to corporate income and are therefore inherently more risky than preferred stock or debt instruments of such issuers. | |||||||||||||
| Concentration Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Concentration Risk The Fund’s investments will be concentrated in issuers in the industry or group of industries that make up the natural resources sector. The Fund has adopted a fundamental investment restriction to invest at least 25% of its total assets in natural resources companies. In addition, in accordance with the Fund’s 80% policy, the Fund invests at least 80% of its net assets plus borrowings for investment purposes in midstream energy investments. Midstream energy companies are a specific type of natural resources company. Because the Fund will be concentrated, it may be subject to more risks than if it were more broadly diversified over numerous industries and sectors of the economy. General changes in market sentiment towards companies in the natural resources sector, or midstream energy companies specifically, may adversely affect the Fund, and the performance of the natural resources sector, or midstream energy companies specifically, may lag behind the broader market as a whole. Also, the Fund’s concentration in the natural resources sector, and midstream energy companies specifically, may subject the Fund to a variety of risks associated with that sector. See “Additional Information (Unaudited)—Risks—Midstream Energy Company Risks.” | |||||||||||||
| Midstream Energy Company Risks | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Midstream Energy Company Risks Midstream energy companies are subject to certain risks, including, but not limited to, the following: Commodity Price Risk . Midstream energy companies may be affected by fluctuations in the prices of commodities, including, for example, natural gas, natural gas liquids and crude oil, in the short- and long-term. Natural resources commodity prices have been very volatile in the past and such volatility is expected to continue. Fluctuations in commodity prices can result from changes in general economic conditions or political circumstances (especially of key energy-consuming countries); market conditions; weather patterns; domestic production levels; volume of imports; energy conservation; domestic and foreign governmental regulation; international politics; policies of the Organization of Petroleum Exporting Countries (“OPEC”); taxation; tariffs; and the availability and costs of local, intrastate and interstate transportation methods. Midstream energy companies engaged in crude oil and natural gas exploration, development or production, natural gas gathering and processing, crude oil refining and transportation and coal mining or sales may be directly affected by their respective natural resources commodity prices. The volatility of, and interrelationships between, commodity prices can also indirectly affect certain other midstream energy companies due to the potential impact on the volume of commodities transported, processed, stored or distributed. Some midstream energy companies that own the underlying energy commodity may be unable to effectively mitigate or manage direct margin exposure to commodity price levels. The natural resources sector as a whole may also be impacted by the perception that the performance of natural resources sector companies is directly linked to commodity prices. The prices of companies’ securities can be adversely affected by market perceptions that their performance and distributions or distributions are directly tied to commodity prices. High commodity prices may drive further energy conservation efforts and a slowing economy may adversely impact energy consumption which may adversely affect the performance of midstream energy companies. Prices of oil and other energy commodities have experienced significant volatility during recent years, including as a result of the pandemic spread of infectious respiratory illness caused by a novel coronavirus known as “COVID-19,” during which demand for energy commodities fell sharply and energy commodity prices reached historic lows, and may continue to experience relatively high volatility for a prolonged period. Companies engaged in crude oil and natural gas exploration, development or production, natural gas gathering and processing, crude oil refining and transportation and coal mining or sales may be directly affected by their respective natural resources commodity prices. The volatility of commodity prices may also indirectly affect certain companies engaged in the transportation, processing, storage or distribution of such commodities. Some companies that own the underlying commodities may be unable to effectively mitigate or manage direct margin exposure to commodity price levels. The natural resources sector as a whole may also be impacted by the perception that the performance of natural resources sector companies is directly linked to commodity prices. As a result, many companies in which the Fund invests may have been and may continue to be adversely impacted by volatility of prices of energy commodities. Reductions in production of oil and other energy commodities may lag decreases in demand or declines in commodity prices, resulting in global oversupply in such commodities. Slower global growth may lower demand for oil and other energy commodities and increased exports by Iran with the end of sanctions may increase supply, exacerbating oversupply of such commodities and further reducing commodity prices. Continued volatility of commodity prices could further erode such companies’ growth prospects and negatively impact such companies’ ability to sustain attractive distribution levels. Cyclicality Risk. The operating results of companies in the broader natural resources sector are cyclical, with fluctuations in commodity prices and demand for commodities driven by a variety of factors. The highly cyclical nature of the natural resources sector may adversely affect the earnings or operating cash flows of the midstream energy companies in which the Fund invests. Supply Risk. The profitability of midstream energy companies, particularly those involved in processing, gathering and pipeline transportation, may be materially impacted by the volume of natural gas or other energy commodities available for transportation, processing, storage or distribution. A significant decrease in the production of natural gas, crude oil, coal or other energy commodities, due to the decline of production from existing resources, import supply disruption, depressed commodity prices or otherwise, would reduce the revenue, operating income and operating cash flows of midstream energy companies and, therefore, their ability to make distributions or pay dividends. The volume of production of energy commodities and the volume of energy commodities available for transportation, storage, processing or distribution could be affected by a variety of factors, including depletion of resources; depressed commodity prices; catastrophic events; labor relations; increased environmental or other governmental regulation; equipment malfunctions and maintenance difficulties; import volumes; international politics; policies of OPEC; and increased competition from alternative energy sources. Demand Risk. A sustained decline in demand for coal, natural gas, natural gas liquids, crude oil and refined petroleum products could adversely affect a midstream energy company’s revenues and cash flows. Factors that could lead to a sustained decrease in market demand include a recession or other adverse economic conditions, an increase in the market price of the underlying commodity that is not, or is not expected to be, merely a short-term increase, higher taxes or other regulatory actions that increase costs, or a shift in consumer demand for such products. Demand may also be adversely affected by consumer sentiment with respect to global warming and by state or federal legislation intended to promote the use of alternative energy sources. Depletion Risk . Companies engaged in the exploration, development, management or production of energy commodities face the risk that commodity reserves are depleted over time. Such companies seek to increase their reserves through expansion of their current businesses, acquisitions, further development of their existing sources of energy commodities, exploration of new sources of energy commodities or by entering into long-term contracts for additional reserves; however, there are risks associated with each of these potential strategies. If such companies fail to acquire additional reserves in a cost-effective manner and at a rate at least equal to the rate at which their existing reserves decline, their financial performance may suffer. Additionally, failure to replenish reserves could reduce the amount and affect the tax characterization of the distributions paid by such companies. Risks Related to Expansions and Acquisitions. Midstream energy companies employ a variety of means to increase cash flow, including increasing utilization of existing facilities, expanding operations through new construction or development activities, expanding operations through acquisitions, or securing additional long-term contracts. Thus, some midstream energy companies may be subject to construction risk, development risk, acquisition risk or other risks arising from their specific business strategies. Midstream energy companies that attempt to grow through acquisitions may not be able to effectively integrate acquired operations with their existing operations. In addition, acquisition or expansion projects may not perform as anticipated. A significant slowdown in merger and acquisition activity in the natural resources sector could reduce the growth rate of cash flows received by the Fund from midstream energy companies that grow through acquisitions. Competition Risk. The natural resources sector is highly competitive. The midstream energy companies in which the Fund invests face substantial competition from other companies, many of which will have greater financial, technological, human and other resources, in acquiring natural resources assets, obtaining and retaining customers and contracts and hiring and retaining qualified personnel. Larger companies may be able to pay more for assets and may have a greater ability to continue their operations during periods of low commodity prices. To the extent that the midstream energy companies in which the Fund invests are unable to compete effectively, their operating results, financial position, growth potential and cash flows may be adversely affected, which could in turn adversely affect the results of the Fund. Weather Risk. Extreme weather conditions could result in substantial damage to the facilities of certain midstream energy companies located in the affected areas and significant volatility in the supply of natural resources, commodity prices and the earnings of midstream energy companies and could therefore adversely affect their securities. Interest Rate Risk. The prices of the equity and debt securities of the midstream energy companies the Fund expects to hold in its portfolio are susceptible in the short-term to a decline when interest rates rise. Rising interest rates could limit the capital appreciation of securities of certain midstream energy companies as a result of the increased availability of alternative investments with comparable yields. Rising interest rates could adversely impact the financial performance of midstream energy companies by increasing their cost of capital. This may reduce their ability to execute acquisitions or expansion projects in a cost-effective manner. The risk of interest rates rising is more pronounced in the current market environment because of recent monetary policy measures and the low interest rate environment in recent years. Business Segment Specific Risk. Midstream energy companies are also subject to risks that are specific to the particular business segment of the natural resources sector in which they operate. Pipelines. Pipeline companies are subject to the demand for natural gas, natural gas liquids, crude oil or refined products in the markets they serve, changes in the availability of products for gathering, transportation, processing or sale due to natural declines in reserves and production in the supply areas serviced by the companies’ facilities, sharp decreases in crude oil or natural gas prices that cause producers to curtail production or reduce capital spending for exploration activities, and environmental regulation. Demand for gasoline, which accounts for a substantial portion of refined product transportation, depends on price, prevailing economic conditions in the markets served, and demographic and seasonal factors. Companies that own interstate pipelines that transport natural gas, natural gas liquids, crude oil or refined petroleum products are subject to regulation by FERC with respect to the tariff rates they may charge for transportation services. An adverse determination by FERC with respect to the tariff rates of such a company could have a material adverse effect on its business, financial condition, results of operations and cash flows of those companies and their ability to pay cash distributions or dividends. In addition, FERC has a tax allowance policy, which permits such companies to include in their cost of service an income tax allowance to the extent that their owners have an actual or potential tax liability on the income generated by them. If FERC’s income tax allowance policy were to change in the future to disallow a material portion of the income tax allowance taken by such interstate pipeline companies, it would adversely impact the maximum tariff rates that such companies are permitted to charge for their transportation services, which would in turn adversely affect the results of operations and cash flows of those companies and their ability to pay cash distributions or dividends to their unit holders or shareholders. Gathering and Processing. Gathering and processing companies are subject to natural declines in the production of oil and natural gas fields, which utilize their gathering and processing facilities as a way to market their production, prolonged declines in the price of natural gas or crude oil, which curtails drilling activity and therefore production and declines in the prices of natural gas liquids and refined petroleum products, which cause lower processing margins. In addition, some gathering, and processing contracts subject the gathering or processing company to direct commodities price risk. Exploration and Production. Exploration, development and production companies are particularly vulnerable to declines in the demand for and prices of crude oil and natural gas. Reductions in prices for crude oil and natural gas can cause a given reservoir to become uneconomic for continued production earlier than it would if prices were higher, resulting in the plugging and abandonment of, and cessation of production from, that reservoir. In addition, lower commodity prices not only reduce revenues but also can result in substantial downward adjustments in reserve estimates. The accuracy of any reserve estimate is a function of the quality of available data, the accuracy of assumptions regarding future commodity prices and future exploration and development costs and engineering and geological interpretations and judgments. Different reserve engineers may make different estimates of reserve quantities and related revenue based on the same data. Actual oil and gas prices, development expenditures and operating expenses will vary from those assumed in reserve estimates, and these variances may be significant. Any significant variance from the assumptions used could result in the actual quantity of reserves and future net cash flow being materially different from those estimated in reserve reports. In addition, results of drilling, testing and production and changes in prices after the date of reserve estimates may result in downward revisions to such estimates. Substantial downward adjustments in reserve estimates could have a material adverse effect on a given exploration and production company’s financial position and results of operations. In addition, due to natural declines in reserves and production, exploration and production companies must economically find or acquire and develop additional reserves in order to maintain and grow their revenues and distributions. Propane. Propane companies are subject to earnings variability based upon weather patterns in the locations where they operate and increases in the wholesale price of propane which reduce profit margins. In addition, propane companies are facing increased competition due to the growing availability of natural gas, fuel oil and alternative energy sources for residential heating. Coal. Coal companies are subject to declines in the demand for and prices of coal. Demand variability can be based on weather conditions, the strength of the domestic economy, the level of coal stockpiles in their customer base, and the prices of competing sources of fuel for electric generation. They are also subject to supply variability based on geological conditions that reduce the productivity of mining operations, the availability of regulatory permits for mining activities and the availability of coal that meets the standards of the federal Clean Air Act of 1990, as amended (the “Clean Air Act”). Demand and prices for coal may also be affected by current and proposed regulatory limitations on emissions from coal-fired power plants and the facilities of other coal end users. Such limitations may reduce demand for the coal produced and transported by coal companies. Certain coal companies could face declining revenues if they are unable to acquire additional coal reserves or other mineral reserves that are economically recoverable. Marine Shipping . Marine shipping companies are subject to supply of and demand for, and level of consumption of, natural gas, liquefied natural gas, crude oil, refined petroleum products and liquefied petroleum gases in the supply areas and market areas they serve, which affect the demand for marine shipping services and therefore charter rates. Shipping companies’ vessels and cargoes are also subject to the risk of being damaged or lost due to marine disasters, extreme weather, mechanical failures, grounding, fire, explosions, collisions, human error, piracy, war and terrorism. Some vessels may also require replacement or significant capital improvements earlier than otherwise required due to changing regulatory standards. Shipping companies or their ships may be chartered in any country and the Fund’s investments in such issuers may be subject to risks similar to risks related to investments in non-U.S. securities. Cash Flow Risk. The Fund will derive substantially all of its cash flow from investments in equity securities of midstream energy companies. The amount of cash that the Fund has available to distribute to shareholders will depend on the ability of the midstream energy companies in which the Fund has an interest to make distributions or pay dividends to their investors and the tax character of those distributions or dividends. The Fund will likely have no influence over the actions of the companies in which it invests with respect to the payment of distributions or dividends. The amount of cash that any individual midstream energy company can distribute to its investors, including the Fund, will depend on the amount of cash it generates from operations, which will vary from quarter to quarter depending on factors affecting the natural resources sector generally and the particular business lines of the issuer. Available cash will also depend on the midstream energy company’s operating costs, capital expenditures, debt service requirements, acquisition costs (if any), fluctuations in working capital needs and other factors. With respect to the Fund’s investments in MLPs, the cash that an MLP will have available for distribution will also depend on the incentive distributions payable to its general partner or managing member in connection with distributions paid to its equity investors. Regulatory Risk . The profitability of midstream energy companies could be adversely affected by changes in the regulatory environment. Midstream energy companies are subject to significant foreign, federal, state and local regulation in virtually every aspect of their operations, including with respect to how facilities are constructed, maintained and operated, environmental and safety controls, and the prices they may charge for the products and services they provide. Such regulation can change over time in both scope and intensity. For example, a particular by-product may be declared hazardous by a regulatory agency and unexpectedly increase production costs. Various governmental authorities have the power to enforce compliance with these regulations and the permits issued under them, and violators are subject to administrative, civil and criminal penalties, including civil fines, injunctions or both. Stricter laws, regulations or enforcement policies could be enacted in the future which would likely increase compliance costs and may adversely affect the financial performance of midstream energy companies. Midstream energy companies may be adversely affected by future regulatory requirements. While the nature of such regulations cannot be predicted at this time, they may impose additional costs or limit certain operations by midstream energy companies. Specifically, the operations of wells, gathering systems, pipelines, refineries and other facilities are subject to stringent and complex federal, state and local environmental laws and regulations. These include, for example: ● the federal Clean Air Act and comparable state laws and regulations that impose obligations related to air emissions. ● the federal Clean Water Act and comparable state laws and regulations that impose obligations related to discharges of pollutants into regulated bodies of water. ● the federal Resource Conservation and Recovery Act (“RCRA”) and comparable state laws and regulations that impose requirements for the handling and disposal of waste from facilities; and ● the federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 (“CERCLA”), also known as “Superfund,” and comparable state laws and regulations that regulate the cleanup of hazardous substances that may have been released at properties currently or previously owned or operated by midstream energy companies or at locations to which they have sent waste for disposal. Failure to comply with these laws and regulations may trigger a variety of administrative, civil and criminal enforcement measures, including the assessment of monetary penalties, the imposition of remedial requirements, and the issuance of orders enjoining future operations. Certain environmental statutes, including RCRA, CERCLA, the federal Oil Pollution Act and analogous state laws and regulations, impose strict, joint and several liability for costs required to clean up and restore sites where hazardous substances have been disposed or otherwise released. Moreover, it is not uncommon for neighboring landowners and other third parties to file claims for personal injury and property damage allegedly caused by the release of hazardous substances or other waste products into the environment. There is an inherent risk that midstream energy companies may incur environmental costs and liabilities due to the nature of their businesses and the substances they handle. For example, an accidental release from wells or gathering pipelines could subject them to substantial liabilities for environmental cleanup and restoration costs, claims made by neighboring landowners and other third parties for personal injury and property damage, and fines or penalties for related violations of environmental laws or regulations. Moreover, the possibility exists that stricter laws, regulations or enforcement policies could significantly increase the compliance costs of midstream energy companies, and the cost of any remediation that may become necessary. Midstream energy companies may not be able to recover these costs from insurance. Proposals for voluntary initiatives and mandatory controls are being discussed both in the United States and worldwide to reduce emissions of “greenhouse gases” such as carbon dioxide, a by-product of burning fossil fuels, and methane, the major constituent of natural gas, which many scientists and policymakers believe contribute to global climate change. These measures, if adopted, could result in increased costs to certain companies in which the Fund invests to operate and maintain natural resources facilities and administer and manage a greenhouse gas emissions program. In the wake of a Supreme Court decision holding that the EPA has some legal authority to deal with climate change under the Clean Air Act, the federal government announced on May 14, 2007 that the EPA and the Departments of Transportation, Energy, and Agriculture would jointly write regulations to cut gasoline use and control greenhouse gas emissions from cars and trucks. These measures if adopted could reduce demand for energy or raise prices, which may adversely affect the total return of certain of the Fund’s investments. Environmental Risk . There is an inherent risk that midstream energy companies may incur environmental costs and liabilities due to the nature of their businesses and the substances they handle. For example, an accidental release from wells or gathering pipelines could subject them to substantial liabilities for environmental cleanup and restoration costs, claims made by neighboring landowners and other third parties for personal injury and property damage, and fines or penalties for related violations of environmental laws or regulations. Moreover, the possibility exists that stricter laws, regulations or enforcement policies could significantly increase the compliance costs of midstream energy companies, and the cost of any remediation that may become necessary. Midstream energy companies may not be able to recover these costs from insurance. In the wake of a Supreme Court decision holding that the EPA has some legal authority to deal with climate change under the Clean Air Act, the EPA and the Department of Transportation jointly wrote regulations to cut gasoline use and control greenhouse gas emissions from cars and trucks. These measures, and other programs addressing greenhouse gas emissions, could reduce demand for energy or raise prices, which may adversely affect the total return of certain of the Fund’s investments. The types of regulations described above can change over time in both scope and intensity, may have adverse effects on midstream energy companies and may be implemented in unforeseen manners on an “emergency” basis in response to catastrophes or other events. Affiliated Party Risk . Certain midstream energy companies are dependent on their parents or sponsors for a majority of their revenues. Any failure by a midstream energy company’s parents or sponsors to satisfy their payments or obligations would impact the midstream energy company’s revenues and cash flows and ability to make distributions. Moreover, the terms of a midstream energy company’s transactions with its parent or sponsor are typically not arrived at on an arm’s-length basis and may not be as favorable to the midstream energy company as a transaction with a non-affiliate. Catastrophe Risk . The operations of midstream energy companies are subject to many hazards inherent in the exploration for, and development, production, gathering, transportation, processing, storage, refining, distribution, mining or marketing of, coal, natural gas, natural gas liquids, crude oil, refined petroleum products or other hydrocarbons, including: damage to production equipment, pipelines, storage tanks or related equipment and surrounding properties or other adverse impacts resulting from hurricanes, tornadoes, floods, fires, climate conditions, extreme weather events and other natural disasters and the responses thereto or acts of terrorism; inadvertent damage from construction or other equipment; leaks of natural gas, natural gas liquids, crude oil, refined petroleum products or other hydrocarbons; and fires and explosions. Since the September 11th terrorist attacks, the U.S. government has issued warnings that energy assets, specifically U.S. pipeline infrastructure, may be targeted in future terrorist attacks. These dangers give rise to risks of substantial losses as a result of loss or destruction of commodity reserves; damage to or destruction of property, facilities and equipment; pollution and environmental damage; and personal injury or loss of life. Any occurrence of such catastrophic events could bring about a limitation, suspension or discontinuation of the operations of midstream energy companies. Midstream energy companies may not be fully insured against all risks inherent in their business operations and therefore accidents and catastrophic events could adversely affect such companies’ operations, financial conditions and ability to pay distributions to shareholders. Legislation Risk . There have been proposals in Congress to eliminate certain tax incentives widely used by oil and gas companies and to impose new fees on certain energy producers. The elimination of such tax incentives and imposition of such fees could adversely affect the natural sector generally or specific midstream energy companies in which the Fund invests. Technology Risk . Some midstream energy companies are focused on developing new technologies and are strongly influenced by technological changes. Technology development efforts by midstream energy companies may not result in viable methods or products. Midstream energy companies may bear high research and development costs, which can limit their ability to maintain operations during periods of organizational growth or instability. Some midstream energy companies may be in the early stages of operations and may have limited operating histories and smaller market capitalizations on average than companies in other sectors. As a result of these and other factors, the value of investments in such midstream energy companies may be considerably more volatile than that in more established segments of the economy. | |||||||||||||
| Risks Associated with an Investment in IPOs | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Risks Associated with an Investment in IPOs Securities purchased by the Fund in initial public offerings (“IPOs”) are often subject to the general risks associated with investments in companies with small market capitalizations, and typically to a heightened degree. Securities issued in IPOs have no trading history, and information about the companies may be available for very limited periods. In addition, the prices of securities sold in an IPO may be highly volatile. At any particular time or from time to time, the Fund may not be able to invest in IPOs, or to invest to the extent desired, because, for example, only a small portion (if any) of the securities being offered in an IPO may be available to the Fund. In addition, under certain market conditions, a relatively small number of companies may issue securities in IPOs. The investment performance of the Fund during periods when it is unable to invest significantly or at all in IPOs may be lower than during periods when the Fund is able to do so. IPO securities may be volatile, and the Fund cannot predict whether investments in IPOs will be successful. | |||||||||||||
| Risks Associated with an Investment in PIPE Transactions | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Risks Associated with an Investment in PIPE Transactions In private investment in public equity (“PIPE”) transactions, the Fund purchases securities directly from a publicly traded company in a private placement transaction, typically at a discount to the market price of the company’s common stock. Because the sale of the securities is not registered under the Securities Act of 1933, as amended (the “Securities Act”), the securities are “restricted” and cannot be immediately resold by the investors into the public markets. Accordingly, the company typically agrees as part of the PIPE deal to register the restricted securities with the SEC. PIPE securities may be deemed illiquid. | |||||||||||||
| Privately Held Company Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Privately Held Company Risk Investing in privately held companies involves risk. For example, privately held companies are not subject to SEC reporting requirements, are not required to maintain their accounting records in accordance with generally accepted accounting principles and are not required to maintain effective internal controls over financial reporting. As a result, the Investment Adviser may not have timely or accurate information about the business, financial condition and results of operations of the privately held companies in which the Fund invests. In addition, the securities of privately held companies are generally illiquid, and entail the risks described under “—Liquidity Risk” below. | |||||||||||||
| MLP Risks | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | MLP Risks An investment in MLP units involves some risks that differ from an investment in the common stock of a corporation. As compared to common stockholders of a corporation, holders of MLP units have more limited control and limited rights to vote on matters affecting the partnership. In addition, there are certain tax risks associated with an investment in MLP units and conflicts of interest may exist between common unit holders and the general partner, including those arising from incentive distribution payments. A portion of the benefit the Fund derives from its investment in equity securities of MLPs is a result of MLPs generally being treated as partnerships for U.S. federal income tax purposes. Partnerships generally do not pay U.S. federal income tax at the partnership level. Rather, each partner of a partnership, in computing its U.S. federal income tax liability, will include its allocable share of the partnership’s income, gains, losses, deductions and expenses. A change in current tax law, or a change in the business of a given MLP, could result in an MLP being treated as a corporation for U.S. federal income tax purposes, which would result in such MLP being required to pay U.S. federal income tax on its taxable income. The classification of an MLP as a corporation for U.S. federal income tax purposes would have the effect of reducing the amount of cash available for distribution by the MLP and causing any such distributions received by the Fund to be treated as dividend income to the extent of the MLP’s current or accumulated earnings and profits. Thus, if any of the MLPs owned by the Fund were treated as corporations for U.S. federal income tax purposes, the after-tax return to the Fund with respect to its investment in such MLPs would be materially reduced, which could cause a decline in the value of the common shares. Recently, a number of MLPs have reduced, suspended or eliminated their distributions. In addition, changes in tax laws or regulations, or future interpretations of such laws or regulations, could adversely affect the Fund or the MLP investments in which the Fund invests. To the extent that the Fund invests in the equity securities of an MLP treated as a partnership under the Code, the Fund will be a partner in such MLP. Accordingly, the Fund will be required to include in its taxable income the Fund’s allocable share of the income, gains, losses, deductions and credits recognized by each such MLP, regardless of whether the MLP distributes cash to the Fund. Historically, MLPs have been able to offset a significant portion of their income with tax deductions. The Fund will recognize taxable income on its allocable share of an MLP’s income and gains that is not offset by the MLP’s tax deductions, losses and credits. The portion, if any, of a distribution received by the Fund from an MLP that is offset by the MLP’s tax deductions, losses or credits is essentially treated as a return of capital. However, those distributions will reduce the Fund’s adjusted tax basis in the equity securities of the MLP, which will result in an increase in the amount of gain (or decrease in the amount of loss) that will be recognized by the Fund for tax purposes upon the sale of any such equity securities and may increase the amount of income or gain that will be recognized by the Fund upon subsequent distributions in respect of such equity securities. The percentage of an MLP’s income and gains that is offset by tax deductions, losses and credits will fluctuate over time for various reasons. For example, a significant slowdown in acquisition activity or capital spending by MLPs held in the Fund’s portfolio could result in a reduction of accelerated depreciation generated by new acquisitions, which may result in a decrease in the portion of the MLP’s distributions that is offset by tax deductions. Because of the Fund’s investments in equity securities of MLPs, the Fund’s earnings and profits may be calculated using accounting methods that are different from those used for calculating taxable income. Because of these differences, the Fund may make distributions out of its current or accumulated earnings and profits, which will be treated as dividends, in years in which the Fund’s distributions exceed its taxable income. Adverse developments in the natural resources sector may result in MLPs seeking to restructure debt or file for bankruptcy. Limited partners in such MLPs, such as the Fund, may owe taxes on debt that is forgiven in a bankruptcy or an out-of-court restructuring, as cancellation of debt income, which creates a tax liability for investors without an associated cash distribution. While an MLP facing a debt restructuring may seek to implement structures that would limit the tax liability associated with the debt restructuring, there can be no assurance that such structures could be successfully implemented or would not have other adverse impacts on the Fund as an investor in the MLP. Adverse developments in the natural resources sector may result in MLPs seeking to restructure debt or file for bankruptcy. Limited partners in such MLPs, such as the Fund, may owe taxes on debt that is forgiven in a bankruptcy or an out-of-court restructuring, as cancellation of debt income, which creates a tax liability for investors without an associated cash distribution. While an MLP facing a debt restructuring may seek to implement structures that would limit the tax liability associated with the debt restructuring, there can be no assurance that such structures could be successfully implemented or would not have other adverse impacts on the Fund as an investor in the MLP. MLP Subordinated Units . Master limited partnership subordinated units are not typically listed on an exchange or publicly traded. Holders of MLP subordinated units are entitled to receive a distribution only after the MQD has been paid to holders of common units, but prior to payment of incentive distributions to the general partner or managing member. Master limited partnership subordinated units generally do not provide arrearage rights. Most MLP subordinated units are convertible into common units after the passage of a specified period of time or upon the achievement by the MLP of specified financial goals. General Partner and Managing Member Interests . General partner and managing member interests are not publicly traded, though they may be owned by publicly traded entities such as GP MLPs. A holder of general partner or managing member interests can be liable in certain circumstances for amounts greater than the amount of the holder’s investment. In addition, while a general partner or managing member’s incentive distribution rights can mean that general partners and managing members have higher distribution growth prospects than their underlying MLPs, these incentive distribution payments would decline at a greater rate than the decline rate in quarterly distributions to common or subordinated unit holders in the event of a reduction in the MLP’s quarterly distribution. A general partner or managing member interest can be redeemed by the MLP if the MLP unit holders choose to remove the general partner, typically by a supermajority vote of the limited partners or members. | |||||||||||||
| Liquidity Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Liquidity Risk The investments made by the Fund may be illiquid and consequently the Fund may not be able to sell such investments at prices that reflect the Investment Adviser’s assessment of their value, the amount paid for such investments by the Fund or at prices approximating the value at which the Fund is carrying the securities on its books. Furthermore, the nature of the Fund’s investments may require a long holding period prior to profitability. Although the equity securities of the companies in which the Fund invests generally trade on major stock exchanges, certain securities may trade less frequently, particularly those with smaller capitalizations. Securities with limited trading volumes may display volatile or erratic price movements. Investment of the Fund’s capital in securities that are less actively traded or over time experience decreased trading volume may restrict the Fund’s ability to take advantage of other market opportunities. Unregistered securities are securities that cannot be sold publicly in the United States without registration under the Securities Act, unless an exemption from such registration is available. Restricted securities may be more difficult to value, and the Fund may have difficulty disposing of such assets either in a timely manner or for a reasonable price. In order to dispose of an unregistered security, the Fund, where it has contractual rights to do so, may have to cause such security to be registered. A considerable period may elapse between the time the decision is made to sell the security and the time the security is registered so that the Fund could sell it. Contractual restrictions on the resale of securities vary in length and scope and are generally the result of a negotiation between the issuer and acquirer of the securities. The Fund would, in either case, bear the risks of any downward price fluctuation during that period. The difficulties and delays associated with selling restricted securities could result in the Fund’s inability to realize a favorable price upon disposition of such securities, and at times might make disposition of such securities impossible. | |||||||||||||
| Equity Securities Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Equity Securities Risk Master limited partnership common units and other equity securities of midstream energy companies can be affected by macroeconomic, political, global and other factors affecting the stock market in general, expectations of interest rates, investor sentiment towards midstream energy companies or the natural resources sector, changes in a particular company’s financial condition, or the unfavorable or unanticipated poor performance of a particular midstream energy company. Prices of common units and other equity securities of individual midstream energy companies can also be affected by fundamentals unique to the partnership or company, including earnings power and coverage ratios. | |||||||||||||
| Small-Cap and Mid-Cap Company Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Small-Cap and Mid-Cap Company Risk Investing in the securities of companies with small or medium-sized market capitalizations (“small-cap” and “mid-cap” companies, respectively) presents some particular investment risks. Small-cap and mid-cap midstream energy companies may have limited product lines and markets, as well as shorter operating histories, less experienced management and more limited financial resources than larger midstream energy companies and may be more vulnerable to adverse general market or economic developments. Stocks of these midstream energy companies may be less liquid than those of larger midstream energy companies and may experience greater price fluctuations than larger midstream energy companies. In addition, small-cap or mid-cap company securities may not be widely followed by investors, which may result in reduced demand. | |||||||||||||
| Risks Associated with Canadian Royalty Trusts and Canadian E&P Companies | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Risks Associated with Canadian Royalty Trusts and Canadian E&P Companies With respect to investments in royalty trusts, potential growth may be sacrificed because revenue is passed on to a royalty trust’s unitholders (such as the Fund), rather than reinvested in the business. Royalty trusts generally do not guarantee minimum distributions or even return of capital. If the assets underlying a royalty trust do not perform as expected, the royalty trust may reduce or even eliminate distributions. The declaration of such distributions generally depends upon various factors, including the operating performance and financial condition of the royalty trust and general economic conditions. Unlike U.S. royalty trusts, Canadian royalty trusts and E&P companies may engage in the acquisition, development and production of natural gas and crude oil to replace depleting reserves. They may have employees, issue new shares, borrow money, acquire additional properties, and manage the resources themselves. As a result, Canadian royalty trusts and Canadian E&P companies are exposed to commodity risk and production and reserve risk, as well as operating risk. | |||||||||||||
| Canadian Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Canadian Risk The Canadian economy is very dependent on the demand for, and supply and price of, natural resources. The Canadian market is relatively concentrated in issuers involved in the production and distribution of natural resources. There is a risk that any changes in the natural resources sector could have an adverse impact on the Canadian economy. The Canadian economy is dependent on the economy of the United States as a key trading partner. Reduction in spending on Canadian products and services or changes in the U.S. economy may cause an impact in the Canadian economy. The Canadian economy may be significantly affected by the U.S. economy, given that the United States is Canada’s largest trading partner and foreign investor. Since the implementation of the North American Free Trade Agreement (“NAFTA”) in 1994, total two-way merchandise trade between the United States and Canada has more than doubled. To further this relationship, all three NAFTA countries entered into The Security and Prosperity Partnership of North America in March 2005, which addressed economic and security related issues, and the US-Mexico-Canada Agreement, which replaced NAFTA effective July 1, 2020. These agreements may further affect Canada’s dependency on the U.S. economy. Past periodic demands by the Province of Quebec for sovereignty have significantly affected equity valuations and foreign currency movements in the Canadian market. | |||||||||||||
| Non-U.S. Securities Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Non-U.S. Securities Risk Investing in non-U.S. securities involves certain risks not involved in domestic investments, including, but not limited to: fluctuations in foreign exchange rates; future foreign economic, financial, political and social developments; different legal systems; the possible imposition of exchange controls or other foreign governmental laws or restrictions, including expropriation; lower trading volume; much greater price volatility and illiquidity of certain non-U.S. securities markets; different trading and settlement practices; less governmental supervision; changes in currency exchange rates; high and volatile rates of inflation; fluctuating interest rates; less publicly available information; and different accounting, auditing and financial recordkeeping standards and requirements. Certain non-U.S. countries, especially emerging market countries, historically have experienced, and may continue to experience, high rates of inflation, high interest rates, exchange rate fluctuations, large amounts of external debt, balance of payments and trade difficulties and extreme poverty and unemployment. Many of these countries are also characterized by political uncertainty and instability. The cost of servicing external debt will generally be adversely affected by rising international interest rates because many external debt obligations bear interest at rates that are adjusted based upon international interest rates. In addition, with respect to certain foreign countries, there is a risk of: the possibility of expropriation or nationalization of assets; confiscatory taxation; difficulty in obtaining or enforcing a court judgment; restrictions on currency repatriation; economic, political or social instability; and diplomatic developments that could affect investments in those countries. Changes in foreign currency exchange rates may affect the value of securities denominated or quoted in currencies other than the U.S. dollar and the unrealized appreciation or depreciation of investments. Currencies of certain countries may be volatile and therefore may affect the value of securities denominated in such currencies, which means that the Fund’s net asset value or current income could decline as a result of changes in the exchange rates between foreign currencies and the U.S. dollar. Certain investments in non-U.S. securities also may be subject to foreign withholding taxes. Dividend income from non-U.S. corporations may not be eligible for the reduced U.S. income tax rate currently available for qualified dividend income. These risks often are heightened for investments in smaller, emerging capital markets. In addition, individual foreign economies may differ favorably or unfavorably from the U.S. economy in such respects as: growth of gross domestic product; rates of inflation; capital reinvestment; resources; self-sufficiency; and balance of payments position. Investing in securities of issuers based in underdeveloped emerging markets entails all of the risks of investing in securities of non-U.S. issuers to a heightened degree. “Emerging market countries” generally include every nation in the world except developed countries, that is the United States, Canada, Japan, Australia, New Zealand and most countries located in Western Europe. These heightened risks include: greater risks of expropriation, confiscatory taxation, nationalization, and less social, political and economic stability; the smaller size of the market for such securities and a lower volume of trading, resulting in lack of liquidity and an increase in price volatility; and certain national policies that may restrict the Fund’s investment opportunities including restrictions on investing in issuers or industries deemed sensitive to relevant national interests. As a result of these potential risks, the Investment Adviser may determine that, notwithstanding otherwise favorable investment criteria, it may not be practicable or appropriate to invest in a particular country. | |||||||||||||
| Interest Rate Hedging Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Interest Rate Hedging Risk The Fund may from time-to-time hedge against interest rate risk resulting from the Fund’s portfolio holdings and any leverage it may incur. Interest rate transactions the Fund may use for hedging purposes will expose the Fund to certain risks that differ from the risks associated with its portfolio holdings. There are economic costs of hedging reflected in the price of interest rate swaps, caps and similar techniques, the cost of which can be significant. In addition, the Fund’s success in using hedging instruments is subject to the Investment Adviser’s ability to correctly predict changes in the relationships of such hedging instruments to the Fund’s leverage risk, and there can be no assurance that the Investment Adviser’s judgment in this respect will be accurate. Depending on the state of interest rates in general, the Fund’s use of interest rate hedging instruments could enhance or decrease investment company taxable income available to the holders of its common shares. To the extent there is a decline in interest rates, the value of interest rate swaps or caps could decline, and result in a decline in the net asset value of the Fund’s common shares. In addition, if the counterparty to an interest rate swap or cap defaults, the Fund would not be able to use the anticipated net receipts under the interest rate swap or cap to offset its cost of leverage. | |||||||||||||
| Arbitrage Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Arbitrage Risk A part of the Investment Adviser’s investment operations may involve spread positions between two or more securities, or derivatives positions including commodities hedging positions, or a combination of the foregoing. The Investment Adviser’s trading operations also may involve arbitraging between two securities or commodities, between the security, commodity and related options or derivatives markets, between spot and futures or forward markets, and/or any combination of the above. To the extent the price relationships between such positions remain constant, no gain or loss on the positions will occur. These offsetting positions entail substantial risk that the price differential could change unfavorably, causing a loss to the position. Certain derivatives transactions have economic characteristics similar to leverage. | |||||||||||||
| Leverage Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Leverage Risk The Fund may use leverage through the issuance of indebtedness or the issuance of preferred shares. The use of leverage magnifies both the favorable and unfavorable effects of price movements in the investments made by the Fund. Insofar as the Fund employs leverage in its investment operations, the Fund will be subject to increased risk of loss. In addition, the Fund will pay (and the holders of common shares will bear) all costs and expenses relating to the issuance and ongoing maintenance of leverage, including higher advisory fees. Similarly, any decline in the net asset value of the Fund’s investments will 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 net asset value to the holders of common shares than if the Fund were not leveraged. This greater net asset value decrease will also tend to cause a greater decline in the market price for the common shares. Leverage creates a greater risk of loss, as well as potential for more gain, for the Fund’s common shares than if leverage is not used. Preferred shares or debt issued by the Fund would have complete priority upon distribution of assets over common shares. Depending on the type of leverage involved, the Fund’s use of leverage may require the approval of its Board of Trustees. The Fund expects to invest the net proceeds derived from any leveraging according to the investment objective and policies described in this Report. So long as the Fund’s portfolio is invested in securities that provide a higher rate of return than the distribution rate or interest rate of the leverage instrument or other borrowing arrangements, after taking its related expenses into consideration, the leverage will cause the Fund’s common shareholders to receive a higher rate of income than if it were not leveraged. There is no assurance that any Fund will continue to utilize leverage or, if leverage is utilized, that it will be successful in enhancing the level of the Fund’s total return. The net asset value of the Fund’s common shares will be reduced by the fees and issuance costs of any leverage. Leverage creates risk for holders of the Fund’s common shares, including the likelihood of greater volatility of net asset value and market price of the shares. Risk of fluctuations in distribution rates or interest rates on leverage instruments or other borrowing arrangements may affect the return to the holders of the Fund’s common shares. To the extent the return on securities purchased with funds received from the use of leverage exceeds the cost of leverage (including increased expenses to the Fund), the Fund’s returns will be greater than if leverage had not been used. Conversely, if the return derived from such securities is less than the cost of leverage (including increased expenses to the Fund), the Fund’s returns will be less than if leverage had not been used, and therefore, the amount available for distribution to the Fund’s common shareholders will be reduced. In the latter case, the Investment Adviser in its best judgment nevertheless may determine to maintain the Fund’s leveraged position if it expects that the benefits to the Fund’s common shareholders of so doing will outweigh the current reduced return. Under normal market conditions, the Fund anticipates that it will be able to invest the proceeds from leverage at a higher rate than the costs of leverage (including increased expenses to the Fund), which would enhance returns to the Fund’s common shareholders. The fees paid to the Investment Adviser will be calculated on the basis of the Fund’s Managed Assets, which include proceeds from leverage instruments and other borrowings. During periods in which the Fund uses leverage, the investment management fee payable to the Investment Adviser will be higher than if the Fund did not use a leveraged capital structure. Consequently, the Fund and the Investment Adviser may have differing interests in determining whether to leverage the Fund’s assets. The Board of Trustees will monitor the Fund’s use of leverage and this potential conflict. | |||||||||||||
| Securities Lending Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Securities Lending Risk The Fund may lend its portfolio securities (up to a maximum of one-third of Managed Assets) to banks or dealers which meet the creditworthiness standards established by the Board of Trustees of the Fund. Securities lending is subject to the risk that loaned securities may not be available to the Fund on a timely basis and the Fund may, therefore, lose the opportunity to sell the securities at a desirable price. Any loss in the market price of securities loaned by the Fund that occurs during the term of the loan would be borne by the Fund and would adversely affect the Fund’s performance. In addition, there may be delays in recovery, or no recovery, of securities loaned or even a loss of rights in the collateral should the borrower of the securities fail financially while the loan is outstanding. These risks may be greater for non-U.S. securities. | |||||||||||||
| Non-Diversification Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Non-Diversification Risk The Fund is a non-diversified, closed-end management investment company under the 1940 Act. Accordingly, the Fund invests a greater portion of its assets in a more limited number of issuers than a diversified fund. An investment in the Fund may present greater risk to an investor than an investment in a diversified portfolio because changes in the financial condition or market assessment of a single issuer may cause greater fluctuations in the value of the Fund’s shares. | |||||||||||||
| Valuation Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Valuation Risk Market prices may not be readily available for certain of the Fund’s investments, and the value of such investments will ordinarily be determined based on fair valuations determined by the Investment Adviser pursuant to procedures adopted by the Board of Trustees and the Investment Adviser as valuation designee. Restrictions on resale or the absence of a liquid secondary market may adversely affect the Fund’s ability to determine such investment’s net asset value. The sale price of securities that are not readily marketable may be lower or higher than the Fund’s most recent determination of their fair value. In addition, the value of these securities typically requires more reliance on the judgment of the Investment Adviser than that required for securities for which there is an active trading market. Due to the difficulty in valuing these securities and the absence of an active trading market for these investments, the Fund may not be able to realize these securities’ true value or may have to delay their sale in order to do so. When determining the fair value of an asset, the Investment Adviser seeks to determine the price that the Fund might reasonably expect to receive from the current sale of that asset in an arm’s length transaction. Fair value pricing, however, involves judgments that are inherently subjective and inexact, since fair valuation procedures are used only when it is not possible to be sure what value should be attributed to a particular asset or when an event will affect the market price of an asset and to what extent. As a result, there can be no assurance that fair value pricing will reflect actual market value, and it is possible that the fair value determined for a security will be materially different from the value that actually could be or is realized upon the sale of that asset. | |||||||||||||
| Portfolio Turnover Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Portfolio Turnover Risk Portfolio turnover rate is not considered a limiting factor in the Investment Adviser’s execution of investment decisions. The Fund anticipates that its annual portfolio turnover rate may vary greatly from year to year. A higher portfolio turnover rate results in correspondingly greater brokerage commissions and other transactional expenses that are borne by the Fund. High portfolio turnover may result in an increased realization of net short-term capital gains or capital losses by the Fund. | |||||||||||||
| Strategic Transactions Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Strategic Transactions Risk The Fund’s use of Strategic Transactions may involve the purchase and sale of derivative instruments. The Fund may purchase and sell exchange-listed and over the counter put and call options on securities, indices and other instruments, enter into forward contracts, purchase and sell futures contracts and options thereon, enter into swap, cap, floor or collar transactions, purchase structured investment products and enter into transactions that combine multiple derivative instruments. Strategic Transactions often have risks similar to the securities underlying the Strategic Transactions. However, the use of Strategic Transactions also involves risks that are different from, and possibly greater than, the risks associated with other portfolio investments. Strategic Transactions may involve the use of highly specialized instruments that require investment techniques and risk analyses different from those associated with other portfolio investments. The use of derivative instruments has risks, including the imperfect correlation between the value of the derivative instruments and the underlying assets, the possible default of the counterparty to the transaction or illiquidity of the derivative investments. Furthermore, the ability to successfully use these techniques depends on the Investment Adviser’s ability to predict pertinent market movements, which cannot be assured. Thus, the use of Strategic Transactions may result in losses greater than if they had not been used, may require the Fund to sell or purchase portfolio securities at inopportune times or for prices other than current market values, may limit the amount of appreciation the Fund can realize on an investment or may cause the Fund to hold a security that it might otherwise sell. In addition, amounts paid by the Fund as premiums and cash, or other assets held in margin accounts with respect to Strategic Transactions, are not otherwise available to the Fund for investment purposes. It is possible that government regulation of various types of derivative instruments, including regulations enacted pursuant to the Dodd-Frank Act, which was signed into law in July 2010, may impact the availability, liquidity and cost of derivative instruments. There can be no assurance that such regulation will not have a material adverse effect on the Fund or will not impair the ability of the Fund to implement certain Strategic Transactions or to achieve their investment objectives. Although the Investment Adviser seeks to use Strategic Transactions to further the Fund’s investment objective, no assurance can be given that the use of Strategic Transactions will achieve this result. | |||||||||||||
| Convertible Instrument Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Convertible Instrument Risk A convertible instrument is a bond, debenture, note, preferred stock or other security that may be converted into or exchanged for a prescribed number of common shares of the same or a different issuer within a particular period of time at a specified price or formula. Convertible debt instruments have characteristics of both fixed income and equity investments. Convertible instruments are subject both to the stock market risk associated with equity securities and to the credit and interest rate risks associated with fixed-income securities. As the market price of the equity security underlying a convertible instrument falls, the convertible instrument tends to trade on the basis of its yield and other fixed-income characteristics. As the market price of such equity security rises, the convertible security tends to trade on the basis of its equity conversion features. Some convertible instruments have varying conversion values. Convertible instruments are typically issued at prices that represent a premium to their conversion value. Accordingly, the value of a convertible instrument increases (or decreases) as the price of the underlying equity security increases (or decreases). If a convertible instrument held by the Fund is called for redemption, the Fund will be required to permit the issuer to redeem the instrument, or convert it into the underlying stock, and will hold the stock to the extent the Investment Adviser determines that such equity investment is consistent with the investment objective of that Fund. | |||||||||||||
| Counterparty Risk | ||||||||||||||
| 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 entered into 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 proceedings. The Fund may obtain only a limited recovery, or may obtain no recovery, in such circumstances. | |||||||||||||
| Short Sales Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Short Sales Risk Short selling involves selling securities which may or may not be owned and borrowing the same securities for delivery to the purchaser, with an obligation to replace the borrowed securities at a later date. Short selling allows the short seller to profit from declines in market prices to the extent such declines exceed the transaction costs and the costs of borrowing the securities. A naked short sale creates the risk of an unlimited loss because the price of the underlying security could theoretically increase without limit, thus increasing the cost of buying those securities to cover the short position. There can be no assurance that the securities necessary to cover a short position will be available for purchase. Purchasing securities to close out the short position can itself cause the price of the securities to rise, further exacerbating the loss. The Fund’s obligation to replace the borrowed security will be secured by collateral deposited with the broker-dealer, usually cash, U.S. government securities or other liquid securities similar to those borrowed. The Fund also will be required to segregate similar collateral to the extent, if any, necessary so that the value of both collateral amounts in the aggregate is at all times equal to at least 100% of the current market value of the security sold short. Depending on arrangements made with the broker-dealer from which the Fund borrowed the security regarding repaying amounts received by the Fund on such security, the Fund may not receive any payments (including interest) on the Fund’s collateral deposited with such broker-dealer. | |||||||||||||
| Inflation Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Inflation Risk Inflation risk is the risk that the value of assets or income from investment will be worth less in the future as inflation decreases the value of money. As inflation increases, the real value of the Fund’s common shares and distributions can decline. Inflation risk is more pronounced in the current market environment because of recent monetary policy measures and the low interest rate environment in recent years. | |||||||||||||
| Deflation Risk | ||||||||||||||
| 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. | |||||||||||||
| Debt Securities Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Debt Securities Risk Debt securities are subject to many of the risks described elsewhere in this section. In addition, they are subject to credit risk, prepayment risk and, depending on their quality, other special risks. Credit Risk . An issuer of a debt security may be unable to make interest payments and repay principal. A Fund could lose money if the issuer of a debt obligation is, or is perceived to be, unable or unwilling to make timely principal and/or interest payments, or to otherwise honor its obligations. The downgrade of a security may further decrease its value. Prepayment Risk . Certain debt instruments, particularly below investment grade securities, may contain call or redemption provisions which would allow the issuer of the debt instrument to prepay principal prior to the debt instrument’s stated maturity. This is also sometimes known as prepayment risk. Prepayment risk is greater during a falling interest rate environment as issuers can reduce their cost of capital by refinancing higher yielding debt instruments with lower yielding debt instruments. An issuer may also elect to refinance its debt instruments with lower yielding debt instruments if the credit standing of the issuer improves. To the extent debt securities in the Fund’s portfolio are called or redeemed, that Fund may be forced to reinvest in lower yielding securities. | |||||||||||||
| Preferred Stock Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Preferred Stock Risk Preferred stocks combine some of the characteristics of both common stocks and debt securities. Preferred stocks generally pay a fixed rate of return and are sold on the basis of current yield, like debt securities. However, because they are equity securities, preferred stock provides equity ownership of a company, and the income is paid in the form of distributions. Preferred stocks typically have a yield advantage over common stocks as well as comparably rated fixed income investments. Preferred stocks are typically subordinated to bonds and other debt instruments in a company’s capital structure, in terms of priority to corporate income, and therefore will be subject to greater credit risk than those debt instruments. Unlike interest payments on debt securities, preferred stock distributions are payable only if declared by the issuer’s boarVd of directors. Preferred stocks also may be subject to optional or mandatory redemption provisions. Convertible preferred stocks have risks similar to convertible securities as described above in “—Convertible Instrument Risk.” | |||||||||||||
| Below Investment Grade Securities (Junk Bonds) Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Below Investment Grade Securities (Junk Bonds) Risk Below investment grade and unrated debt securities generally pay a premium above the yields of U.S. government securities or debt securities of investment grade issuers because they are subject to greater risks than those securities. These risks, which reflect their speculative character, include the following: greater yield and price volatility; greater credit risk and risk of default; 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. Debt securities rated below investment grade are commonly known as “junk bonds” and are regarded as predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal in accordance with the terms of the obligations and involve major risk exposure to adverse conditions. The prices of these below investment grade and unrated debt securities are more sensitive to negative developments, such as a decline in the issuer’s revenues, downturns in profitability in the natural resources sector or a general economic downturn, than are the prices of higher-grade securities. Below investment grade and unrated debt securities tend to be less liquid than investment grade securities and the market for below investment grade and unrated debt securities could contract further under adverse market or economic conditions. In such a scenario, it may be more difficult for the Fund to sell these securities in a timely manner or for as high a price as could be realized if such securities were more widely traded. The market value of below investment grade and unrated debt securities may be more volatile than the market value of investment grade 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 investment grade securities, which primarily reflect fluctuations in general levels of interest rates. In the event of a default by a below investment grade or unrated debt security held in the Fund’s portfolio in the payment of principal or interest, the Fund may incur additional expense to the extent the Fund is required to seek recovery of such principal or interest. | |||||||||||||
| Other Investment Companies Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Other Investment Companies Risk Investments in investment company securities are subject to the risks of the purchased investment company’s portfolio securities. In addition, Fund shareholders will bear not only their proportionate share of the expenses of the Fund (including operating expenses and the fees of the investment adviser), but also will indirectly bear similar expenses of the underlying investment company in which the Fund invests. Certain investments company securities, including other closed-end funds and ETFs, may trade at market prices that differ from the net asset value of the particular fund. In addition, the securities of other investment companies may also be leveraged and will therefore be subject to the same leverage risks described herein. As described in the section entitled “—Leverage Risk,” the net asset value and market value of leveraged shares will be more volatile and the yield to stockholders will tend to fluctuate more than the yield generated by unleveraged shares. Other investment companies may have investment policies that differ from those of the Fund and the value of such investments will be dependent upon the investment and research abilities of persons other than the Investment Adviser. | |||||||||||||
| ETN and ETF Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | ETN and ETF Risk An exchange-traded note (“ETN”) or exchange-traded fund (“ETF”) that is based on a specific index may not be able to replicate and maintain exactly the composition and relative weighting of securities in the index. An ETN or ETF also incurs certain expenses not incurred by its applicable index. The market value of an ETN or ETF share may differ from its net asset value; the share may trade at a premium or discount to its net asset value, which may be due to, among other things, differences in the supply and demand in the market for the share and the supply and demand in the market for the underlying assets of the ETN or ETF. In addition, certain securities that are part of the index tracked by an ETN or ETF may, at times, be unavailable, which may impede the ETN’s or ETF’s ability to track its index. An ETF that uses leverage can, at times, be relatively illiquid, which can affect whether its share price approximates net asset value. As a result of using leverage, an ETF is subject to the risk of failure in the futures and options markets it uses to obtain leverage and the risk that a counterparty will default on its obligations, which can result in a loss to the Fund. If the Fund invests in ETFs, the Fund’s shareholders will bear not only their proportionate share of the expenses of the Fund, but also will indirectly bear similar expenses of the underlying ETF. Although an ETN is a debt security, it is unlike a typical bond, in that there are no periodic interest payments and principal is not protected. | |||||||||||||
| Investment Management Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Investment Management Risk The Fund’s portfolio is subject to investment management risk because it will be actively managed. The Investment Adviser will apply investment techniques and risk analyses in making investment decisions for the Fund, but there can be no guarantee that they will produce the desired results. The decisions with respect to the management of the Fund are made exclusively by the Investment Adviser, subject to the oversight of the Board of Trustees. Investors have no right or power to take part in the management of the Fund. The Investment Adviser also is responsible for all of the trading and investment decisions of the Fund. In the event of the withdrawal or bankruptcy of the Investment Adviser, generally the affairs of the Fund will be wound-up, and its assets will be liquidated. | |||||||||||||
| Dependence on Key Personnel of the Investment Adviser | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Dependence on Key Personnel of the Investment Adviser The Fund is dependent upon the Investment Adviser’s key personnel for its future success and upon their access to certain individuals and investments in the natural resources sector. In particular, the Fund will depend on the diligence, skill and network of business contacts of the personnel of the Investment Adviser and its portfolio managers, who will evaluate, negotiate, structure, close and monitor the Fund’s investments. The portfolio managers have equity interests and other financial incentives to remain with the firm. The Fund will also depend on the senior management of the Investment Adviser. The departure of a member or members of the Investment Adviser’s senior management could have a material adverse effect on the Fund’s ability to achieve its investment objective. In addition, the Fund can offer no assurance that the Investment Adviser will remain its investment adviser, or that the Fund will continue to have access to the Investment Adviser’s natural resources sector contacts and deal flow. | |||||||||||||
| Conflicts of Interest with the Investment Adviser | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Conflicts of Interest with the Investment Adviser Conflicts of interest may arise because the Investment Adviser and its affiliates generally will be carrying on substantial investment activities for other clients, including, but not limited to, other client accounts and funds managed or advised by the Investment Adviser, in which the Fund will have no interest. The Investment Adviser or its affiliates may have financial incentives to favor certain of such accounts over the Fund. Any of their proprietary accounts and other customer accounts may compete with the Fund for specific trades. The Investment Adviser or its affiliates may buy or sell securities for the Fund which differ from securities bought or sold for other accounts and customers, even though their investment objectives and policies may be similar to the Fund’s. Situations may occur when the Fund could be disadvantaged because of the investment activities conducted by the Investment Adviser and its affiliates for their other accounts. Such situations may be based on, among other things, legal or internal restrictions on the combined size of positions that may be taken for the Fund and the other accounts, limiting the size of the Fund’s position, or the difficulty of liquidating an investment for the Fund and the other accounts where the market cannot absorb the sale of the combined position. Notwithstanding these potential conflicts of interest, the Fund’s Board of Trustees and officers have a fiduciary obligation to act in the Fund’s best interest. The Fund’s investment opportunities may be limited by affiliations of the Investment Adviser or its affiliates with midstream energy companies. In addition, to the extent that the Investment Adviser sources and structures private investments in midstream energy companies, certain employees of the Investment Adviser may become aware of actions planned by midstream energy companies, such as acquisitions that may not be announced to the public. It is possible that the Fund could be precluded from investing in a company about which the Investment Adviser has material non-public information; however, it is the Investment Adviser’s intention to ensure that any material non-public information available to certain of the Investment Adviser’s employees not be shared with those employees responsible for the purchase and sale of publicly traded securities. The Investment Adviser manages several other client accounts and funds. Some of these other client accounts and funds have investment objectives that are similar to or overlap with the Fund. Furthermore, the Investment Adviser may at some time in the future manage additional client accounts and investment funds with the same investment objective as the Fund. The Investment Adviser and its affiliates generally will be carrying on substantial investment activities for other clients’ accounts and funds in which the Fund will have no interest. Investment decisions for the Fund are made independently from those of such other clients; however, from time to time, the same investment decision may be made for more than one fund or account. When two or more clients advised by the Investment Adviser or its affiliates seek to purchase or sell the same publicly traded securities, the securities actually purchased or sold will be allocated among the clients on a good faith equitable basis by the Investment Adviser in its discretion in accordance with the clients’ various investment objectives and procedures adopted by the Investment Adviser and approved by the Fund’s Board of Trustees. In some cases, this system may adversely affect the price or size of the position the Fund may obtain. The Fund’s investment opportunities may be limited by investment opportunities that the Investment Adviser is evaluating for other clients’ accounts and funds. To the extent a potential investment is appropriate for the Fund and one or more of the Investment Adviser’s other client accounts or funds, the Investment Adviser will need to fairly allocate that investment to the Fund or another client account or fund, or both, depending on its allocation procedures and applicable law related to combined or joint transactions. There may occur an attractive limited investment opportunity suitable for the Fund in which the Fund cannot invest under the particular allocation method being used for that investment. Under the 1940 Act, the Fund and such other client accounts or funds managed or advised by the Investment Adviser may be precluded from co-investing in certain private placements of securities. Except as permitted by law or positions of the staff of the SEC, the Investment Adviser will not co-invest its other clients’ assets in private transactions in which the Fund invests. To the extent the Fund is precluded from co-investing, the Investment Adviser will allocate private investment opportunities among its clients, including but not limited to the Fund and its other client accounts and funds, based on allocation policies that take into account several suitability factors, including the size of the investment opportunity, the amount each client has available for investment and the client’s investment objectives. These allocation policies may result in the allocation of investment opportunities to another client account or fund managed or advised by the Investment Adviser rather than to the Fund. The management fees payable to the Investment Adviser are based on the value of the Fund’s Managed Assets, as periodically determined. A portion of the Fund’s Managed Assets may be illiquid securities acquired in private transactions for which market quotations will not be readily available. Although the Fund and the Investment Adviser as valuation designee have adopted valuation procedures designed to determine valuations of illiquid securities in a manner that reflects their fair value, there typically is a range of possible prices that may be established for each individual security. See “—Valuation Risk.” Skadden, Arps, Slate, Meagher & Flom LLP, counsel to the Fund, also represents the Investment Adviser. Such counsel does not purport to represent the separate interests of the investors and has assumed no obligation to do so. Accordingly, the investors have not had the benefit of independent counsel in the structuring of the Fund or determination of the relative interests, rights and obligations of the Investment Adviser and the investors. | |||||||||||||
| Reliance on Service Providers | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Reliance on Service Providers The Fund relies upon service providers to perform certain functions, which may include functions that are integral to the operations and financial performance of the Fund. Fees and expenses of these service providers are borne by the Fund, and therefore indirectly by common shareholders. 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 ability to achieve its investment objective. 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 that Fund and could have a material adverse effect on the Fund’s performance and ability to achieve its investment objective. | |||||||||||||
| Technology Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Technology Risk As the use of Internet technology has become more prevalent, the Fund and its service providers and markets generally have become more susceptible to potential operational risks related to intentional and unintentional events that may cause the Fund or a service provider to lose proprietary information, suffer data corruption or lose operational capacity. There can be no guarantee that any risk management systems established by the Fund, its service providers, or issuers of the securities in which the Fund invests to reduce technology and cyber security risks will succeed, and the Fund cannot control such systems put in place by service providers, issuers or other third parties whose operations may affect the Fund. | |||||||||||||
| Cyber Security Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Cyber Security Risk As the use of technology has become more prevalent in the course of business, the Fund has become potentially more susceptible to operational and informational security risks resulting from breaches in cyber security. A breach in cyber security refers to both intentional and unintentional cyber events that may, among other things, cause the Fund to lose proprietary information, suffer data corruption and/or destruction, lose operational capacity, result in the unauthorized release or other misuse of confidential information, or otherwise disrupt normal business operations. In addition, cyber security breaches involving the Fund’s third-party service providers (including but not limited to advisers, administrators, transfer agents, custodians, distributors and other third parties), trading counterparties or issuers in which the Fund invests in can also subject the Fund to many of the same risks associated with direct cyber security breaches. Like with operational risk in general, the Fund has established risk management systems and business continuity plans designed to reduce the risks associated with cyber security. However, there are inherent limitations in these plans and systems, including that certain risks may not have been identified, in large part because different or unknown threats may emerge in the future. As such, there is no guarantee that such efforts will succeed, especially because the Fund does not directly control the cyber security systems of issuers in which the Fund invests, trading counterparties or third-party service providers to the Fund. There is also a risk that cyber security breaches may not be detected. The Fund and its shareholders could be negatively impacted as a result. | |||||||||||||
| Tax Risks | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Tax Risks The Fund has elected to be treated, and intends to continue to qualify to be treated, as a RIC under section 851 of the Code. In order to continue to qualify as a RIC, the Fund must, among other things, satisfy income, asset diversification and distribution requirements. As long as the Fund so qualifies, it will generally not be subject to U.S. federal income tax to the extent that it distributes annually the Fund taxable income and gains. There can be no assurance that the Fund will qualify as a RIC for any given year. | |||||||||||||
| Distributions Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Distributions Risk The Fund’s net investment income can vary significantly over time; however, the Fund seeks to maintain a more stable monthly distribution per share. The distributions paid by the Fund for any particular month may be more or less than the amount of net investment income for that monthly period. The Fund may distribute more than the entire amount of the net investment income earned in a particular period, in which case all or a portion of a distribution may be a return of capital. The Fund’s distributions have historically included, and may in the future include, a significant portion of return of capital. For the fiscal year ended November 30, 2023, the Fund’s distributions were comprised of approximately [ ]% ordinary income and [ ]% return of capital. Accordingly, shareholders should not assume that the source of a distribution from the Fund is net income or profit, and the Fund’s distributions should not be used as a measure of performance or confused with yield or income. Return of capital is the return of a portion of the shareholder’s original investment up to the amount of the Common Shareholder’s tax basis in their Common Shares, which would reduce such tax basis. Although a return of capital may not be taxable, it will generally increase the Common Shareholder’s potential gain, or reduce the Common Shareholder’s potential loss, on any subsequent sale or other disposition of Common Shares. In any given year, there can be no guarantee the Fund’s investment returns will exceed the amount of distributions. To the extent the amount of distributions paid to shareholders in cash exceeds the total net investment returns of the Fund, the assets of the Fund will decline, which may have the effect of increasing the Fund’s expense ratio. In addition, in order to make such distributions, the Fund may have to sell a portion of its investment portfolio at a time when independent investment judgment might not dictate such action. Shareholders should not assume that the source of a distribution from the Fund is net income or profit, and the Fund’s distributions should not be used as a measure of performance or confused with yield or income. | |||||||||||||
| Market Discount from Net Asset Value | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Market Discount from Net Asset Value Shares of closed-end investment companies frequently trade at a discount from their net asset value, which is a risk separate and distinct from the risk that the Fund’s net asset value could decrease as a result of its investment activities. Although the value of the Fund’s net assets is generally considered by market participants in determining whether to purchase or sell common shares, whether investors will realize gains or losses upon the sale of common shares will depend entirely upon whether the market price of common shares at the time of sale is above or below the investor’s purchase price for common shares. Because the market price of common shares will be determined by factors such as net asset value, distribution and distribution levels (which are dependent, in part, on expenses), supply of and demand for common shares, stability of distributions or distributions, trading volume of common shares, general market and economic conditions and other factors beyond the control of the Fund, the Fund cannot predict whether common shares will trade at, below or above net asset value or at, below or above the initial public offering price. Common shares of the Fund are designed primarily for long-term investors; investors in common shares should not view their Fund as a vehicle for trading purposes. | |||||||||||||
| Recent Market, Economic and Social Developments Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Recent Market, Economic and Social Developments Risk Periods of market volatility remain, and 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 the Fund’s 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, the Fund’s 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 unfavorable economic conditions could impair the Fund’s ability to achieve its investment objective. 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 U.S. and around the world, social and political discord, debt crises sovereign debt downgrades, increasingly strained relations between the U.S. 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 EU or the EMU, 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 U.S. and worldwide. In particular, the consequences of the Russian military invasion of Ukraine, including comprehensive international sanctions, the impact on inflation and increased disruption to supply chains and energy resources 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 net asset value. We have no way to predict the duration or outcome of the situation, as the conflict and government reactions are rapidly developing and beyond our control. Prolonged unrest, military activities, or broad-based sanctions could have a material adverse effect on our portfolio companies. Such consequences also may increase our funding cost or limit our access to the capital markets. The current political climate has intensified concerns about a potential trade war between China and the U.S., as each country has 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 the business, financial condition and results of operations of the Fund. | |||||||||||||
| Legislation and Regulatory Risks | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Legislation and Regulatory Risks At any time after the date of this Report, legislation may be enacted that could negatively affect the companies in which the Fund invests. Changing approaches to regulation may also have a negative impact on companies in which the Fund invests. In addition, legislation or regulation may change the way in which the Fund is regulated. There can be no assurance that future legislation, regulation or deregulation will not have a material adverse effect on the Fund or will not impair the ability of the Fund to achieve its investment objective. The Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”), which was signed into law in July 2010, has resulted in significant revisions to the U.S. financial regulatory framework. The Dodd-Frank Act covers a broad range of topics, including, among many others: a reorganization of federal financial regulators; the creation of a process designed to ensure financial system stability and the resolution of potentially insolvent financial firms; the enactment of new rules for derivatives trading; the creation of a consumer financial protection watchdog; the registration and regulation of managers of private funds; the regulation of rating agencies; and the enactment of new federal requirements for residential mortgage loans. The regulation of various types of derivative instruments pursuant to the Dodd-Frank Act may adversely affect the Fund or its counterparties. The SEC and its staff are also reportedly engaged in various initiatives and reviews that seek to improve and modernize the regulatory structure governing investment companies. These efforts appear to be focused on risk identification and controls in various areas, including embedded leverage through the use of derivatives and other trading practices, cybersecurity, liquidity, enhanced regulatory and public reporting requirements and the evaluation of systemic risks. Any new rules, guidance or regulatory initiatives resulting from these efforts could increase the Fund’s expenses and impact its returns to shareholders or, in the extreme case, impact or limit the Fund’s use of various portfolio management strategies or techniques and adversely impact the Fund. Changes enacted by the current presidential administration could significantly impact the regulation of financial markets in the United States. Areas subject to potential change, amendment or repeal include trade and foreign policy, corporate tax rates, energy and infrastructure policies, the environment and sustainability, criminal and social justice initiatives, immigration, healthcare and the oversight of certain federal financial regulatory agencies and the Federal Reserve. Certain of these changes can, and have, been effectuated through executive order. For example, the current administration has taken steps to address the COVID-19 pandemic, rejoin the Paris climate accord of 2015, cancel the Keystone XL pipeline, change immigration enforcement priorities and increase spending on clean energy and infrastructure. Other potential changes that could be pursued by the current presidential administration could include an increase in the corporate income tax rate and changes to regulatory enforcement priorities. It is not possible to predict which, if any, of these actions will be taken or, if taken, their effect on the economy, securities markets or the financial stability of the United States. 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. Although the Fund cannot predict the impact, if any, of these changes to the Fund’s business, they could adversely affect the Fund’s business, financial condition, operating results and cash flows. Until the Fund knows what policy changes are made and how those changes impact the Fund’s business and the business of the Fund’s competitors over the long term, the Fund will not know if, overall, the Fund will benefit from them or be negatively affected by them. The Investment Adviser intends to monitor developments and seeks to manage the Fund’s portfolio in a manner consistent with achieving the Fund’s investment objectives, but there can be no assurance that it will be successful in doing so. | |||||||||||||
| LIBOR Discontinuation Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | LIBOR Discontinuation Risk In July 2017, the head of the United Kingdom Financial Conduct Authority announced the desire to phase out the use of LIBOR by the end of 2021. LIBOR can no longer be used to calculate new deals as of December 31, 2021. Since December 31, 2021, all sterling, euro, Swiss franc and Japanese yen LIBOR settings and the 1-week and 2-month U.S. dollar LIBOR settings have ceased to be published or are no longer representative, and since June 30, 2023, the overnight, 1-month, 3-month, 6-month and 12-month U.S. dollar LIBOR settings ceased to be published or are no longer representative. On June 22, 2017, the Alternative Reference Rates Committee (the “ARRC”) convened by the Federal Reserve and the Federal Reserve Bank of New York identified the Secured Overnight Financing Rate (“SOFR”) as the rate that, in the consensus view of the ARRC, represented best practice for use in certain new U.S. dollar derivatives and other financial contracts. SOFR is a broad measure of the cost of borrowing cash overnight collateralized by U.S. Treasury securities, and has been published by the Federal Reserve Bank of New York since April 2018. The Federal Reserve Bank of New York has also been publishing historical indicative Secured Overnight Financing Rates from 2014. Investors should not rely on any historical changes or trends in SOFR as an indicator of future changes in SOFR. The composition and characteristics of SOFR are not the same as those of LIBOR, and SOFR is fundamentally different from LIBOR for two key reasons. First, SOFR is a secured rate, while LIBOR is an unsecured rate. Second, SOFR is an overnight rate, while LIBOR is a forward-looking rate that represents interbank funding over different maturities (e.g., three months). As a result, there can be no assurance that SOFR will perform in the same way as LIBOR would have at any time, including, without limitation, as a result of changes in interest and yield rates in the market, market volatility or global or regional economic, financial, political, regulatory, judicial or other events. Additionally, there can be no guarantee that SOFR will gain market acceptance as a replacement for U.S. dollar LIBOR. Any failure of SOFR to gain market acceptance could negatively affect financial markets in general and present heightened risks, including with respect to the Fund’s investments. As a result of this uncertainty and developments relating to the transition process, the Fund and its investments may be adversely affected. | |||||||||||||
| Terrorism, Market Disruption, and Catastrophe Risk | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Terrorism, Market Disruption, and Catastrophe Risk Terrorist attacks, catastrophes, pandemics and other geopolitical events have led to, and may in the future lead to, increased short-term market volatility and may have long-term effects on U.S. and world economies and markets. Global political and economic instability could affect the operations of companies in which the Fund invests in unpredictable ways, including through disruptions of natural resources supplies and markets and the resulting volatility in commodity prices. The operation of infrastructure assets in which the Fund invests is subject to many hazards including damage to equipment and surrounding properties caused by hurricanes, tornadoes, floods, fires and other natural disasters or by acts of terrorism; inadvertent damage from construction or other equipment; leaks; and fires and explosions. The U.S. government has issued warnings that infrastructure assets may be future targets of terrorist activities. In addition, changes in the insurance markets have made certain types of insurance more difficult, if not impossible, to obtain and have generally resulted in increased premium costs. | |||||||||||||
| Not a Complete Investment Program | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Not a Complete Investment Program The Fund is intended for investors seeking a high level of total return with an emphasis on current income. The Fund is not meant to provide a vehicle for those who wish to exploit short-term swings in the stock market and is intended for long-term investors. An investment in shares of the Fund should not be considered a complete investment program. Each shareholder should take into account their Fund’s investment objective as well as the shareholder’s other investments when considering an investment in the Fund. | |||||||||||||
| Anti-Takeover Provisions in the Funds Agreement and Declaration of Trust and By-Laws | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Anti-Takeover Provisions in the Fund’s Agreement and Declaration of Trust and By-Laws The Fund’s Second Amended and Restated Agreement and Declaration of Trust, as amended (the “Declaration of Trust”), and By-Laws include provisions that could have the effect of limiting the ability of other entities or persons to acquire control of the Fund or to change the composition of its Board of Trustees. For example, the Declaration of Trust limits the ability of persons to beneficially own (within the meaning of Section 382 of the Code) more than 4.99% of the outstanding Common Shares of the Fund. This restriction was adopted in order to reduce the risk of the Fund undergoing an “ownership change” within the meaning of Section 382 of the Code, which would limit the Fund’s ability to use a capital loss carryforward and certain unrealized losses (if such tax attributes exist). In addition, as a Delaware statutory trust, the Fund is subject to the control share acquisition statute (the “Control Share Statute”) contained in Subchapter III of the Delaware Statutory Trust Act (the “DSTA”), which became automatically applicable to listed closed-end funds, such as the Fund, upon its effective date of August 1, 2022 (the “Effective Date”). The Control Share Statute provides that an acquirer of shares above a series of voting power thresholds has no voting rights under the DSTA or the governing documents of the Fund with respect to shares acquired in excess of that threshold (i.e., the “control shares”) unless approved by shareholders. The ownership restrictions set forth in the Fund’s Declaration of Trust and the limitations of the Control Share Statute could have the effect of depriving shareholders of an opportunity to sell their shares at a premium over prevailing market prices by discouraging a third party from seeking to obtain control over the Fund and may reduce market demand for the Fund’s Common Shares, which could have the effect of increasing the likelihood that the Fund’s Common Shares trade at a discount to net asset value and increasing the amount of any such discount. | |||||||||||||
| Interest Rate Risk [Member] | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Risk [Text Block] | Interest Rate Risk Interest rate risk is the risk that fixed rate securities such as preferred and debt securities will decline in value because of increases in market interest rates. When market interest rates rise, the market value of such securities generally will fall. Longer-term fixed rate securities are generally more sensitive to interest rate changes. Greater sensitivity to changes in interest rates typically corresponds to increased volatility and increased risk. The Fund’s investment in such securities means that the net asset value and market price of, and distributions on, common shares will tend to decline if the market interest rates rise. Duration is a measure of sensitivity to changes in interest rates and reflects a variety of factors, including the maturity and variability, if any, of the interest rate and the call potential of the security. For this reason, duration should not be confused with maturity. If a portfolio has a duration of three years and interest rates increase by 1%, then, all else being equal, the portfolio would decline in value by approximately 3%. These risks may be greater in the current market environment because while interest rates were historically low in recent years, the Federal Reserve has been increasing the Federal Funds rate to address inflation. Any interest rate increases in the future could cause the value of the Fund to decrease. The risk of loss on preferred securities due to rising market interest rates may be exacerbated by extension risk, which is the risk of a preferred security’s expected maturity and duration lengthening, and therefore the interest rate risk that it presents increasing, if and when market interest rates rise. Extension risk is caused by the fact that preferred securities are typically callable by the issuer, and callable fixed rate securities are more likely to be called in a lower market interest rate environment (because the issuer can refinance those securities at low current market rates); conversely, callable fixed rate securities become less likely to be called if market interest rates rise. Because rising market interest rates reduce the likelihood that an issuer will exercise its right to call a preferred security, such an interest rate rise causes the duration of that security, and therefore its interest rate risk going forward, to increase, thus increasing, in an accelerating manner, the degree to which any further interest rate rise will cause the security to lose value. Additionally, the costs associated with any leverage used by the Fund are likely to increase when interest rates rise. Accordingly, the market price of the Fund’s common shares may decline when interest rates rise. The risk of interest rates rising is more pronounced in the current market environment because of recent monetary policy measures and the low interest rate environment in recent years. | |||||||||||||
| Common Shares | ||||||||||||||
| General Description of Registrant [Abstract] | ||||||||||||||
| Return at Minus Ten [Percent] | (14.80%) | |||||||||||||
| Return at Minus Five [Percent] | (8.13%) | |||||||||||||
| Return at Zero [Percent] | (1.46%) | |||||||||||||
| Return at Plus Five [Percent] | 5.20% | |||||||||||||
| Return at Plus Ten [Percent] | 11.87% | |||||||||||||
| Lowest Price or Bid | $ 34.30 | $ 34.41 | $ 30.17 | $ 32.27 | $ 30.80 | $ 27.03 | $ 30.76 | $ 29.13 | $ 27.89 | $ 25.87 | $ 22.73 | $ 20.84 | ||
| Highest Price or Bid | 43.76 | 43.15 | 35 | 36.71 | 37.81 | 36.23 | 36.19 | 33.98 | 35.90 | 31.59 | 28.92 | 25.12 | ||
| Lowest Price or Bid, NAV | 35.58 | 35.58 | 34.92 | 38 | 34.86 | 34.73 | 39.24 | 34.64 | 36.53 | 34.18 | 31.07 | 27.41 | ||
| Highest Price or Bid, NAV | $ 39.34 | $ 39.75 | $ 40.08 | $ 41.07 | $ 43.93 | $ 46.57 | $ 44.87 | $ 38.74 | $ 41.82 | $ 41.41 | $ 37.34 | $ 33.36 | ||
| Highest Price or Bid, Premium (Discount) to NAV [Percent] | 11.24% | 8.55% | (12.67%) | (10.62%) | (13.93%) | (22.20%) | (19.34%) | (12.29%) | (14.16%) | (23.73%) | (22.55%) | (24.70%) | ||
| Lowest Price or Bid, Premium (Discount) to NAV [Percent] | (3.60%) | (3.29%) | (13.60%) | (15.08%) | (11.65%) | (22.17%) | (21.61%) | (15.91%) | (23.65%) | (24.31%) | (26.84%) | (23.97%) | ||
| Share Price | $ 35.04 | $ 35.04 | ||||||||||||
| NAV Per Share | $ 38.81 | $ 38.81 | ||||||||||||
| Latest Premium (Discount) to NAV [Percent] | 9.71% | |||||||||||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||||||||||
| Outstanding Security, Title [Text Block] | Common Shares of Beneficial Interest | |||||||||||||
| Outstanding Security, Held [Shares] | 0 | |||||||||||||
| Outstanding Security, Not Held [Shares] | 2,184,950 | |||||||||||||
| [1]If Common Shares to which this Report relates are sold to or through underwriters, the Prospectus Supplement will set forth any applicable sales load and the estimated offering expenses borne by the Fund.[2][3]Based upon net assets attributable to common shares as of November 30, 2023.[4]The Fund pays the Investment Adviser an annual fee, payable monthly, in an amount equal to 1.25% of the Fund’s average weekly Managed Assets. The fee shown above is based upon outstanding leverage of 19% of the Fund’s Managed Assets (or 23% of the Fund’s net assets attributable to common shares). If leverage of more than 19% of the Fund’s Managed Assets (or 23% of the Fund’s net assets attributable to common shares) is used, the management fees, as a percentage of net assets attributable to common shares would be higher than as shown above. “Other expenses” are estimated based upon those incurred during the fiscal period ended November 30, 2023. Other expenses do not include expense related to realized or unrealized investment gains or losses. See “Additional Information (Unaudited)—Management of the Fund—Fund Expenses.” | ||||||||||||||