| N-2 - USD ($) | 3 Months Ended | 12 Months Ended | ||||||||
| Dec. 31, 2023 | Sep. 30, 2023 | Jun. 30, 2023 | Mar. 31, 2023 | Dec. 31, 2022 | Sep. 30, 2022 | Jun. 30, 2022 | Mar. 31, 2022 | Dec. 31, 2023 | ||
| Cover [Abstract] | ||||||||||
| Entity Central Index Key | 0001385763 | |||||||||
| Amendment Flag | false | |||||||||
| Document Type | N-CSR | |||||||||
| Entity Registrant Name | Nuveen Core Equity Alpha Fund | |||||||||
| Fee Table [Abstract] | ||||||||||
| Shareholder Transaction Expenses [Table Text Block] | SUMMARY OF FUND EXPENSES The purpose of the tables and the examples below are to help you understand all fees and expenses that you, as a common shareholder, would bear directly or indirectly. The tables show the expenses of each Fund as a percentage of the average net assets applicable to Common Shares and not as a percentage of total assets or managed assets. Shareholder Transaction Expenses SPXX QQQX JCE Maximum Sales Charge (as a percentage of offering price) 4.00% (1) 4.00% (1) 1.00% (2) Dividend Reinvestment Plan Fees (3) $2.50 $2.50 $2.50 (1) A maximum sales charge of 4.00% applies only to offerings pursuant to a syndicated underwriting. The maximum sales charge for offerings made at-the-market is 1.00%. There is no sales charge for offerings pursuant to a private transaction. (2) The maximum sales charge for offerings made at-the-market is 1.00%. If the Common Shares are sold to or through underwriters in an offering that is not made at-the-market, the applicable Prospectus Supplement will set forth any other applicable sales load and the estimated offering expenses. Fund shareholders will pay all offering expenses involved with an offering. (3) You will be charged a $2.50 service charge and pay brokerage charges if you direct Computershare Inc. and Computershare Trust Company, N.A., as agent for the common shareholders, to sell your Common Shares held in a dividend reinvestment account. | |||||||||
| Sales Load [Percent] | [1] | 1% | ||||||||
| Dividend Reinvestment and Cash Purchase Fees | [2] | $ 2.5 | ||||||||
| Other Transaction Expenses [Abstract] | ||||||||||
| Annual Expenses [Table Text Block] | As a Percentage of Net Assets Attributable to Common Shares Annual Expenses SPXX QQQX JCE Management Fees 0.82% 0.83% 0.91% Acquired Fund Fees and Expenses 0.01% 0.00% (2) 0.00% (2) Other Expenses (3) 0.12% 0.09% 0.11% Total Annual Expenses 0.95% 0.92% 1.02% (1) Stated as percentages of average net assets attributable to Common Shares for the fiscal year ended December 31, 2023. (2) Expenses attributable to the Fund’s investments, if any, in other investment companies are currently estimated not to exceed 0.01%. (3) Other Expenses are based on estimated amounts for the current fiscal year. | |||||||||
| Management Fees [Percent] | [3] | 0.91% | ||||||||
| Acquired Fund Fees and Expenses [Percent] | [3],[4] | 0% | ||||||||
| Other Annual Expenses [Abstract] | ||||||||||
| Other Annual Expenses [Percent] | [3],[5] | 0.11% | ||||||||
| Total Annual Expenses [Percent] | [3] | 1.02% | ||||||||
| Expense Example [Table Text Block] | Examples The following examples illustrate the expenses, including the applicable transaction fees (referred to as the “Maximum Sales Charge” in the Shareholder Transaction Expenses table above), if any, that a common shareholder would pay on a $1,000 investment that is held for the time periods provided in the table. Each example assumes that all dividends and other distributions are reinvested in the Fund and that the Fund’s Annual Expenses, as provided above, remain the same. The examples also assume a 5% annual return. Actual expenses may be greater or less than those assumed. Moreover, the Fund’s actual rate of return may be greater or less than the hypothetical 5% return shown in the examples. Example # 1 (At-the-Market Transaction) The following example assumes a transaction fee of 1.00%, as a percentage of the offering price. 1 Year 3 Years 5 Years 10 Years SPXX $20 $40 $62 $125 QQQX $19 $39 $60 $122 JCE $20 $42 $66 $134 | |||||||||
| Expense Example, Year 01 | $ 20 | |||||||||
| Expense Example, Years 1 to 3 | 42 | |||||||||
| Expense Example, Years 1 to 5 | 66 | |||||||||
| Expense Example, Years 1 to 10 | $ 134 | |||||||||
| Purpose of Fee Table , Note [Text Block] | The purpose of the tables and the examples below are to help you understand all fees and expenses that you, as a common shareholder, would bear directly or indirectly. The tables show the expenses of each Fund as a percentage of the average net assets applicable to Common Shares and not as a percentage of total assets or managed assets. | |||||||||
| Basis of Transaction Fees, Note [Text Block] | as a percentage of offering price | |||||||||
| Other Expenses, Note [Text Block] | Other Expenses are based on estimated amounts for the current fiscal year. | |||||||||
| Acquired Fund Fees and Expenses, Note [Text Block] | Expenses attributable to the Fund’s investments, if any, in other investment companies are currently estimated not to exceed 0.01%. | |||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Investment Objectives and Practices [Text Block] | Investment Objective The Fund’s investment objective is to provide an attractive level of total return. The Fund seeks to achieve its investment objective primarily through long term capital appreciation and secondarily through income and gains. Investment Policies Under normal circumstances, the Fund will invest at least 80% of its Assets (as defined below) in the Equity Portfolio (as defined below). The Fund invests in a portfolio of actively managed large capitalization U.S. common stocks, using the sub-adviser’s proprietary quantitative process designed to provide the potential for long-term outperformance (the “Equity Portfolio”). Additionally, the Fund seeks to reduce the volatility of its returns relative to the returns of the Equity Portfolio over extended periods by writing (selling) index call options and/or call options on custom baskets of securities (the “Options Strategy”). “Assets” means net assets of the Fund plus the amount of any borrowings for investment purposes. “Managed Assets” mean the total assets of the Fund, minus the sum of its accrued liabilities (other than Fund liabilities incurred for the express purpose of creating leverage). Total assets for this purpose shall include assets attributable to the Fund’s use of leverage (whether or not those assets are reflected in the Fund’s financial statements for purposes of generally accepted accounting principles), and derivatives will be valued at their market value. Under normal market conditions: · The notional value of the call options written by the Fund under its Options Strategy may be up to 50% of the value of the Fund’s Managed Assets. · The Fund intends to limit the overlap between the stocks held in the Equity Portfolio and the stocks underlying the Fund’s call options to less than 70% (generally based on the value of such components). · The Fund may invest up to 10% of is Managed Assets in securities of other open- or closed-end investment companies (including ETFs) that invest primarily in securities of the types in which the Fund may invest directly. In addition, the Fund may invest a portion of its Managed Assets in pooled investment vehicles (other than investment companies) that invest primarily in securities of the types in which the Fund may invest directly. The foregoing policies apply only at the time of any new investment. Approving Changes in Investment Policies The Board of Trustees of the Fund may change the policies described above without a shareholder vote. However, with respect to the Fund’s policy of investing at least 80% of its Assets in the Equity Portfolio, such policy may not be changed without 60 days’ prior written notice to shareholders. Portfolio Contents The Fund generally invests in a portfolio of common stocks. Common stock generally represents an equity ownership interest in an issuer, without preference over and with a lower priority than any other class of securities, including such issuer’s debt securities, preferred stock and other senior equity securities. Common stocks usually carry voting rights and earn dividends. Common stocks fluctuate in price in response to many factors including historical and prospective earnings of the issuer, the value of its assets, general economic conditions, interest rates, investor perceptions and market liquidity, as such the company may or may not pay dividends. Dividends on common stocks are declared at the discretion of the company’s board. In addition, common stock generally has the greatest appreciation and depreciation potential because increases and decreases in earnings are usually reflected in a company’s stock price. The Fund implements its Option Strategy by writing (selling) index call options and call options on custom baskets of securities. An option contract is a contract that gives the holder of the option, in return for a premium, the right to buy from (in the case of a call) or sell to (in the case of a put) the writer of the option the reference instrument underlying the option (or the cash value of the index) at a specified exercise price at any time during the term of the option. The writer of an option on a security has the obligation upon exercise of the option to deliver the reference instrument (or the cash) upon payment of the exercise price or to pay the exercise price upon delivery of the reference instrument (or the cash). Upon exercise of an index option, the writer of an option on an index is obligated to pay the difference between the cash value of the index and the exercise price multiplied by the specified multiplier for the index option. Options may be “covered,” meaning that the party required to deliver the reference instrument if the option is exercised owns that instrument (or has set aside sufficient assets to meet its obligation to deliver the instrument). Options may be listed on an exchange or traded in the OTC market. In general, exchange-traded options have standardized exercise prices and expiration dates and may require the parties to post margin against their obligations, and the performance of the parties’ obligations in connection with such options is guaranteed by the exchange or a related clearing corporation. OTC options have more flexible terms negotiated between the buyer and the seller, but generally are subject to counterparty risk. The ability of the Fund to transact business with any one or any number The Fund writes index call options on broad-based indices and may, if the sub-adviser deems conditions appropriate, write call options on a variety of other equity market indices. As the seller of an index call option, the Fund receives a premium from the purchaser. The purchaser of the index call option has the right to any appreciation in the value of the index over the exercise price upon the exercise of the call option or the expiration date. If, at expiration, the purchaser exercises the index option sold by the Fund, the Fund will pay the purchaser the difference between the cash value of the index and the exercise price of the index option. The premium, the exercise price and the market value of the index determine the gain or loss realized by the Fund as the seller of the index call option. The Fund may also write call options on custom baskets of securities. A custom basket call option is an OTC option with a counterparty whose value is linked to the market value of a portfolio of underlying securities and is collateralized by a portion of the Fund’s Equity Portfolio. In order to minimize the difference between the returns of the underlying securities in the custom basket (commonly referred to as a tracking error), the sub-adviser will use optimization calculations when selecting the individual securities for inclusion in the custom basket. In addition to the use of call options as described above, the Fund may enter into certain derivative instruments in pursuit of its investment objective, including to seek to enhance return, to hedge certain risks of its investments or as a substitute for a position in the underlying asset. Such instruments include options, futures contracts, index futures and total return swaps. In addition, the Fund may invest in other types of derivative instruments that are currently non-principal investments, including forward contracts, interest rate swaps, caps, collars and floors, credit default swaps, and swap options. The Fund may enter into repurchase agreements (the purchase of a security coupled with an agreement to resell that security at a higher price) with respect to its permitted investments. The Fund’s repurchase agreements will provide that the value of the collateral underlying the repurchase agreement will always be at least equal to the repurchase price, including any accrued interest earned on the agreement, and will be marked-to-market daily. The Fund may invest in illiquid securities (i.e., securities that are not readily marketable), including, but not limited to, restricted securities (securities the disposition of which is restricted under the federal securities laws), securities that may be resold only pursuant to Rule 144A under the 1933 Act, and repurchase agreements with maturities in excess of seven days. The Fund may buy and sell securities on a when-issued or delayed delivery basis, making payment or taking delivery at a later date, normally within 15 to 45 days of the trade date. The Fund may lend securities representing up to one-third of the value of its total assets to broker-dealers, banks, and other institutions to generate additional income. When the Fund loans its portfolio securities, it will receive, at the inception of each loan, cash collateral equal to at least 102% of the value of the loaned securities. Under the Fund’s securities lending agreement, the securities lending agent will generally bear the risk that a borrower may default on its obligation to return loaned securities. The Fund, however, will be responsible for the risks associated with the investment of cash collateral. The Fund may lose money on its investment of cash collateral or may fail to earn sufficient income on its investment to meet its obligations to the borrower. Use of Leverage As a non-fundamental policy, the Fund will not leverage its capital structure by issuing senior securities such as the issuance of preferred shares of beneficial interest or debt instruments. The Fund may, however, borrow up to 7.5% of its Managed Assets for cash management purposes. In addition, the Fund may borrow for temporary or emergency purposes and may enter into certain derivatives transactions that have the economic effect of leverage by creating additional investment exposure. Temporary Defensive Periods During temporary defensive periods the Fund may deviate from its investment objective and policies, and in order to keep the Fund’s cash fully invested, the Fund may invest up to 100% of its Managed Assets in investment grade debt securities, including obligations issued or guaranteed by the U.S. government, its agencies and instrumentalities. The Fund may not achieve its investment objective during such periods. | |||||||||
| Risk Factors [Table Text Block] | PRINCIPAL RISKS OF THE FUNDS The factors that are most likely to have a material effect on a particular Fund’s portfolio as a whole are called “principal risks.” Each Fund is subject to the principal risks indicated below, whether through direct investment or derivative positions. Each Fund may be subject to additional risks other than those identified and described below because the types of investments made by a Fund can change over time. Risk BXMX DIAX SPXX QQQX JCE Portfolio Level Risks Call Option Risk X X X X X Call Spreads Risk X X X X - Common Stock Risk X X X X X Concentration Risk X X X X - Counterparty Risk X X X X X Deflation Risk X X X X X Derivatives Risk X X X X X Dividend Income Risk X X X X X Frequent Trading Risk - - - - X Financial Services Sector Risk - X X - X Hedging Risk X X X X X Illiquid Investments Risk X X X X - Inflation Risk X X X X X Information Technology Sector Risk X - X - - Large -Cap Company Risk X X X X X Non-U.S. Securities Risk X X X X - Option Strategy Risk X X X X X Other Investment Companies Risk X X X X X Put Option Risk X X X X - Quantitative Analysis Risk - - - - X Swap Transactions Risk X X X X X Technology Company Investment Risk - - - X - Valuation Risk X X X X X Risk BXMX DIAX SPXX QQQX JCE Fund Level and Other Risks Anti-Takeover Provisions X X X X X Borrowing Risk X X X X X Cybersecurity Risk X X X X X Global Economic Risk X X X X X Investment and Market Risk X X X X X Legislation and Regulatory Risk X X X X X Market Discount from Net Asset Value X X X X X Non-Diversified Status Risk - X - X - Not an Index Fund X X X X - Recent Market Conditions X X X X X Fund Tax Risk X X X X X Portfolio Level Risks: Call Option Risk. In addition, because the exercise of index options is settled in cash, sellers of index call options, such as the Fund, cannot provide in advance for their potential settlement obligations by acquiring and holding the underlying securities. The Fund bears a risk that the value of the securities held by the Fund will vary from the value of the underlying index and relative to the written index call option positions. Accordingly, the Fund may incur losses on the index call options that it has sold that exceed gains on the Fund’s equity portfolio. The value of index options written by the Fund, which will be priced daily, will be affected by changes in the value of and dividend rates of the underlying common stocks in the index, changes in the actual or perceived volatility of the stock market and the remaining time to the options’ expiration. The value of the index options also may be adversely affected if the market for the index options becomes less liquid or smaller. Call Spreads Risk. Common Stock Risk. Concentration Risk. Counterparty Risk. Deflation Risk. Derivatives Risk. It is possible that regulatory or other developments in the derivatives market, including changes in government regulation could adversely impact the Fund’s ability to invest in certain derivatives successfully use derivative instruments. Dividend Income Risk. Frequent Trading Risk. Hedging Risk. Illiquid Investments Risk. Inflation Risk. Information Technology Sector Risk. Large-Cap Company Risk. Non-U.S. Securities Risk. Option Strategy Risk. Other Investment Companies Risk. With Put Option Risk. Quantitative Analysis Risk. Swap Transactions Risk. Technology Company Investment Risk. Valuation Risk. Fund Level and Other Risks: Anti-Takeover Provisions. Borrowing Risk. Cybersecurity Risk. Global Economic Risk. as COVID-19 that was first detected in China in December 2019 and heightened concerns regarding North Korea’s nuclear weapons and long-range ballistic missile programs. In addition, Russia’s invasion of Ukraine in February 2022 has resulted in sanctions imposed by several nations, such as the United States, United Kingdom, European Union and Canada. The current sanctions and potential further sanctions may negatively impact certain sectors of Russia’s economy, but also may negatively impact the value of the Fund’s investments that do not have direct exposure to Russia. These events could reduce consumer demand or economic output, result in market closure, travel restrictions or quarantines, and generally have a significant impact on the global economy. These events could also impair the information technology and other operational systems upon which the Fund’s service providers, including the Fund’s sub-adviser, rely, and could otherwise disrupt the ability of employees of the Fund’s service providers to perform essential tasks on behalf of the Fund. The Fund does not know and cannot predict how long the securities markets may be affected by these events and the future impact of these and similar events on the global economy and securities markets is uncertain. The Fund may be adversely affected by abrogation of international agreements and national laws which have created the market instruments in which the Fund may invest, failure of the designated national and international authorities to enforce compliance with the same laws and agreements, failure of local, national and international organizations to carry out the duties prescribed to them under the relevant agreements, revisions of these laws and agreements which dilute their effectiveness or conflicting interpretation of provisions of the same laws and agreements. Governmental and quasi-governmental authorities and regulators throughout the world have in the past responded to major economic disruptions with a variety of significant fiscal and monetary policy changes, including but not limited to, direct capital infusions into companies, new monetary programs and dramatically lower interest rates. An unexpected or quick reversal of these policies, or the ineffectiveness of these policies, could increase volatility in securities markets, which could adversely affect the Fund’s investments. Investment and Market Risk. Legislation and Regulatory Risk. Market Discount from Net Asset Value. Non-Diversified Status Risk. Not an Index Fund. Recent Market Conditions. Ukraine has experienced ongoing military conflict, most recently in February 2022 when Russia invaded Ukraine; this conflict may expand and military attacks could occur elsewhere in Europe. Europe has also been struggling with mass migration from the Middle East and Africa. The ultimate effects of these events and other socio-political or geographical issues are not known but could profoundly affect global economies and markets. Additionally, in October 2023 armed conflict broke out between Israel and the militant group Hamas after Hamas infiltrated Israel’s southern border from the Gaza Strip. Israel has since declared war against Hamas and it’s possible that this conflict could escalate into a greater regional conflict. The ultimate effects of these events and other socio-political or geographical issues are not known but could profoundly affect global economies and markets. The ongoing trade war between China and the United States, including the imposition of tariffs by each country on the other country’s products, has created a tense political environment. 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 the Fund’s 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. The U.S. Federal Reserve (the “Fed”) has in the past raised interest rates and has signaled an intention to continue to do so or maintain higher interest rates until current inflation levels re-align with the Fed’s long-term inflation target. Changing interest rate environments impact the various sectors of the economy in different ways. For example, in March 2023, the Federal Deposit Insurance Corporation (“FDIC”) was appointed receiver for each of Silicon Valley Bank and Signature Bank, the second- and third-largest bank failures in U.S. history, which failures may be attributable, in part, to rising interest rates. Bank failures may have a destabilizing impact on the broader banking industry or markets generally. The impact of these developments in the near- and long-term is unknown and could have additional adverse effects on economies, financial markets and asset valuations around the world. Fund Tax Risk. | |||||||||
| Share Price [Table Text Block] | TRADING AND NET ASSET VALUE INFORMATION The following table shows for the periods indicated: (i) the high and low market prices for the Common Shares of Nuveen S&P 500 Dynamic Overwrite Fund (SPXX) and Nuveen Core Equity Alpha Fund (JCE) reported as of the end of the day on the New York Stock Exchange (NYSE) and Nuveen Nasdaq 100 Dynamic Overwrite Fund (QQQX) reported as of the end of the day on the Nasdaq Stock Market LLC (Nasdaq), (ii) the high and low net asset value (NAV) of the Common Shares, and (iii) the high and low of the premium/(discount) to NAV (expressed as a percentage) of shares of the Common Shares. Market Price NAV Premium/(Discount) to NAV Fiscal Quarter End High Low High Low High Low December 2023 $14.02 $11.65 $13.49 $12.01 4.41 % (3.00) % September 2023 $13.16 $12.12 $13.55 $12.40 (0.08) % (4.44) % June 2023 $12.90 $11.82 $13.31 $12.43 (1.51) % (6.39) % March 2023 $13.54 $11.82 $12.96 $11.90 12.46 % (3.24) % December 2022 $16.17 $12.12 $13.07 $11.58 30.09 % (1.70) % September 2022 $16.13 $11.93 $15.10 $12.33 8.16 % (4.56) % June 2022 $17.45 $12.62 $16.46 $13.07 6.86 % (5.72) % March 2022 $18.58 $14.69 $17.44 $15.09 7.61 % (5.69) % The following table shows, as of December 31, 2023 each Fund’s: (i) NAV per Common Share, (ii) market price, (iii) percentage of premium/(discount) to NAV per Common Share and, (iv) net assets attributable to Common Shares. December 31, 2023 SPXX QQQX JCE NAV per Common Share $ 16.29 $ 24.68 $ 13.28 Market Price $ 15.04 $ 23.15 $ 13.55 Percentage of Premium/(Discount) to NAV per Common Share (7.67)% (6.20)% 2.03% Net Assets Attributable to Common Shares $ 292,557,743 $ 1,204,825,050 $ 213,669,234 Shares of closed-end investment companies, including those of the Funds, may frequently trade at prices lower than NAV, the Funds’ Board of Trustees (Board) has currently determined that, at least annually, it will consider action that might be taken to reduce or eliminate any material discount from NAV in respect of Common Shares, which may include the repurchase of such shares in the open market or in private transactions, the making of a tender offer for such shares at NAV, or the conversion of the Fund to an open-end investment company. The Funds cannot assure you that their Board will decide to take any of these actions, or that share repurchases or tender offers will actually reduce market discount. | |||||||||
| Call Option Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Call Option Risk. In addition, because the exercise of index options is settled in cash, sellers of index call options, such as the Fund, cannot provide in advance for their potential settlement obligations by acquiring and holding the underlying securities. The Fund bears a risk that the value of the securities held by the Fund will vary from the value of the underlying index and relative to the written index call option positions. Accordingly, the Fund may incur losses on the index call options that it has sold that exceed gains on the Fund’s equity portfolio. The value of index options written by the Fund, which will be priced daily, will be affected by changes in the value of and dividend rates of the underlying common stocks in the index, changes in the actual or perceived volatility of the stock market and the remaining time to the options’ expiration. The value of the index options also may be adversely affected if the market for the index options becomes less liquid or smaller. | |||||||||
| Common Stock Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Common Stock Risk. | |||||||||
| Counterparty Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Counterparty Risk. | |||||||||
| Deflation Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Deflation Risk. | |||||||||
| Derivatives Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Derivatives Risk. It is possible that regulatory or other developments in the derivatives market, including changes in government regulation could adversely impact the Fund’s ability to invest in certain derivatives successfully use derivative instruments. | |||||||||
| Dividend Income Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Dividend Income Risk. | |||||||||
| Frequent Trading Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Frequent Trading Risk. | |||||||||
| Hedging Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Hedging Risk. | |||||||||
| Inflation Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Inflation Risk. | |||||||||
| LargeCap Company Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Large-Cap Company Risk. | |||||||||
| Option Strategy Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Option Strategy Risk. | |||||||||
| Other Investment Companies Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Other Investment Companies Risk. With | |||||||||
| Quantitative Analysis Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Quantitative Analysis Risk. | |||||||||
| Swap Transactions Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Swap Transactions Risk. | |||||||||
| Valuation Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Valuation Risk. | |||||||||
| Anti-Takeover Provisions | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Anti-Takeover Provisions. | |||||||||
| Borrowing Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Borrowing Risk. | |||||||||
| Cybersecurity Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Cybersecurity Risk. | |||||||||
| Global Economic Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Global Economic Risk. as COVID-19 that was first detected in China in December 2019 and heightened concerns regarding North Korea’s nuclear weapons and long-range ballistic missile programs. In addition, Russia’s invasion of Ukraine in February 2022 has resulted in sanctions imposed by several nations, such as the United States, United Kingdom, European Union and Canada. The current sanctions and potential further sanctions may negatively impact certain sectors of Russia’s economy, but also may negatively impact the value of the Fund’s investments that do not have direct exposure to Russia. These events could reduce consumer demand or economic output, result in market closure, travel restrictions or quarantines, and generally have a significant impact on the global economy. These events could also impair the information technology and other operational systems upon which the Fund’s service providers, including the Fund’s sub-adviser, rely, and could otherwise disrupt the ability of employees of the Fund’s service providers to perform essential tasks on behalf of the Fund. The Fund does not know and cannot predict how long the securities markets may be affected by these events and the future impact of these and similar events on the global economy and securities markets is uncertain. The Fund may be adversely affected by abrogation of international agreements and national laws which have created the market instruments in which the Fund may invest, failure of the designated national and international authorities to enforce compliance with the same laws and agreements, failure of local, national and international organizations to carry out the duties prescribed to them under the relevant agreements, revisions of these laws and agreements which dilute their effectiveness or conflicting interpretation of provisions of the same laws and agreements. Governmental and quasi-governmental authorities and regulators throughout the world have in the past responded to major economic disruptions with a variety of significant fiscal and monetary policy changes, including but not limited to, direct capital infusions into companies, new monetary programs and dramatically lower interest rates. An unexpected or quick reversal of these policies, or the ineffectiveness of these policies, could increase volatility in securities markets, which could adversely affect the Fund’s investments. | |||||||||
| Investment and Market Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Investment and Market Risk. | |||||||||
| Legislation and Regulatory Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Legislation and Regulatory Risk. | |||||||||
| Market Discount from Net Asset Value [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Market Discount from Net Asset Value. | |||||||||
| Recent Market Conditions [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Recent Market Conditions. Ukraine has experienced ongoing military conflict, most recently in February 2022 when Russia invaded Ukraine; this conflict may expand and military attacks could occur elsewhere in Europe. Europe has also been struggling with mass migration from the Middle East and Africa. The ultimate effects of these events and other socio-political or geographical issues are not known but could profoundly affect global economies and markets. Additionally, in October 2023 armed conflict broke out between Israel and the militant group Hamas after Hamas infiltrated Israel’s southern border from the Gaza Strip. Israel has since declared war against Hamas and it’s possible that this conflict could escalate into a greater regional conflict. The ultimate effects of these events and other socio-political or geographical issues are not known but could profoundly affect global economies and markets. The ongoing trade war between China and the United States, including the imposition of tariffs by each country on the other country’s products, has created a tense political environment. 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 the Fund’s 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. The U.S. Federal Reserve (the “Fed”) has in the past raised interest rates and has signaled an intention to continue to do so or maintain higher interest rates until current inflation levels re-align with the Fed’s long-term inflation target. Changing interest rate environments impact the various sectors of the economy in different ways. For example, in March 2023, the Federal Deposit Insurance Corporation (“FDIC”) was appointed receiver for each of Silicon Valley Bank and Signature Bank, the second- and third-largest bank failures in U.S. history, which failures may be attributable, in part, to rising interest rates. Bank failures may have a destabilizing impact on the broader banking industry or markets generally. The impact of these developments in the near- and long-term is unknown and could have additional adverse effects on economies, financial markets and asset valuations around the world. | |||||||||
| Fund Tax Risk [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Risk [Text Block] | Fund Tax Risk. | |||||||||
| Common Shares [Member] | ||||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Lowest Price or Bid | $ 11.65 | $ 12.12 | $ 11.82 | $ 11.82 | $ 12.12 | $ 11.93 | $ 12.62 | $ 14.69 | ||
| Highest Price or Bid | 14.02 | 13.16 | 12.9 | 13.54 | 16.17 | 16.13 | 17.45 | 18.58 | ||
| Lowest Price or Bid, NAV | 12.01 | 12.4 | 12.43 | 11.9 | 11.58 | 12.33 | 13.07 | 15.09 | ||
| Highest Price or Bid, NAV | $ 13.49 | $ 13.55 | $ 13.31 | $ 12.96 | $ 13.07 | $ 15.1 | $ 16.46 | $ 17.44 | ||
| Highest Price or Bid, Premium (Discount) to NAV [Percent] | 4.41% | (0.08%) | (1.51%) | 12.46% | 30.09% | 8.16% | 6.86% | 7.61% | ||
| Lowest Price or Bid, Premium (Discount) to NAV [Percent] | (3.00%) | (4.44%) | (6.39%) | (3.24%) | (1.70%) | (4.56%) | (5.72%) | (5.69%) | ||
| Share Price | $ 13.55 | $ 13.55 | ||||||||
| NAV Per Share | $ 13.28 | $ 13.28 | ||||||||
| Latest Premium (Discount) to NAV [Percent] | 2.03% | |||||||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||||||
| Outstanding Security, Title [Text Block] | Common shares | |||||||||
| Outstanding Security, Held [Shares] | 16,084,218 | |||||||||
| [1]The maximum sales charge for offerings made at-the-market is 1.00%. If the Common Shares are sold to or through underwriters in an offering that is not made at-the-market, the applicable Prospectus Supplement will set forth any other applicable sales load and the estimated offering expenses. Fund shareholders will pay all offering expenses involved with an offering.[2]You will be charged a $2.50 service charge and pay brokerage charges if you direct Computershare Inc. and Computershare Trust Company, N.A., as agent for the common shareholders, to sell your Common Shares held in a dividend reinvestment account.[3]Stated as percentages of average net assets attributable to Common Shares for the fiscal year ended December 31, 2023.[4]Expenses attributable to the Fund’s investments, if any, in other investment companies are currently estimated not to exceed 0.01%.[5]Other Expenses are based on estimated amounts for the current fiscal year. | ||||||||||
