| N-2 - $ / shares | 12 Months Ended | |||||
| Dec. 31, 2023 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
| Cover [Abstract] | ||||||
| Entity Central Index Key | 0000813623 | |||||
| Amendment Flag | false | |||||
| Document Type | N-CSR | |||||
| Entity Registrant Name | Swiss Helvetia Fund, Inc. | |||||
| General Description of Registrant [Abstract] | ||||||
| Investment Objectives and Practices [Text Block] | Investment Objective and Principal Investment Strategies The following summarizes the Fund’s current investment objective and principal investment strategies: Investment Objective The Fund’s investment objective is to seek long-term capital appreciation through investment in equity and equity-linked securities of Swiss companies. The Fund also may acquire and hold equity and equity-linked securities of non-Swiss companies in the limited instance where: (1) the Fund holds an investment in a Swiss company, and (2) such Swiss company undergoes a merger, takeover, reorganization or other form of business combination with a non-Swiss issuer (a “reorganization”), or reorganizes (or “redomiciles”) itself as a new corporate entity outside of Switzerland, and (3) the Fund, as a stockholder in the Swiss company, acquires equity or equity-linked securities in the non-Swiss issuer as a result of the transaction. The Fund would be permitted, but not required, to reacquire equity and equity-linked securities of Swiss companies that have redomiciled, so long as the Fund held an investment in the Swiss company at or before the time the company redomiciled. The Fund’s investment objective is fundamental and may not be changed without the approval of a majority of the Fund’s outstanding voting securities. Principal Investment Strategies The Fund seeks to achieve its investment objective by normally investing at least 80% of its net assets, plus borrowings for investment purposes, in Swiss-equity and equity linked securities that are traded on a Swiss stock exchange, traded at the pre-bourse level of one or more Swiss stock exchanges, traded through a market maker or over the counter in Switzerland. The Fund also may invest in Swiss-equity and equity-linked securities of Swiss companies that are traded on other major European stock exchanges. Equity and equity-linked securities include registered shares, bearer shares, participation and dividend certificates, convertible bonds and bonds with warrants attached and unattached warrants. For defensive purposes, during a period in which changes in Swiss equity markets or other adverse economic conditions or changes in Swiss political conditions warrant, the Fund may temporarily reduce its position in equity securities and invest in Sfr-denominated bank deposits, short-term debt or money market instruments. The Fund may invest in securities of Swiss Real Estate Companies (as defined below), and acquire, hold and sell real estate or mortgages on real estate acquired through default, liquidation or other distributions or an interest in real estate as a result of the Fund’s ownership of such securities. Additionally, the Fund may invest a portion of its assets in investment companies and in certain pooled investment vehicles, including those that invest in private equity by investing in private equity funds (so-called “funds of funds”) or by making direct investments, including in infrastructure projects and real estate investments. The Fund is permitted to (i) leverage up to 10% of its total assets (including the amount borrowed) and (ii) engage in certain options transactions. The Fund may borrow money for investment purposes and as a temporary measure for various purposes, including the payment of dividends. The Fund may enter into options to hedge market risk and to generate income. No assurance can be given that the Fund’s investment objective will be achieved. Investment Philosophy and Process In making investment decisions securities are evaluated for the opportunity for capital appreciation as well as for their potential to provide regular income and growth of income. The Adviser reviews each company’s potential for success in light of general economic and industry trends, as well as the company’s quality of management, financial condition, business plan, industry and sector market position, dividend payout ratio and corporate governance. Fundamental research efforts are enhanced through communication among the portfolio managers and the company’s management team, who conduct internal research and extract information from external research. The portfolio managers communicate frequently with external analysts, and in-person visits with company management, together with local knowledge, help to provide opinions critical to investing in Swiss companies. The macroeconomic environment is reflected in fair value models. It is also taken into account in portfolio construction, where disciplined risk diversification is applied. In addition, the Adviser incorporates financially material environmental, social and governance (ESG) factors into its investment process. The Adviser evaluates the impact and risk around issues such as climate change, environmental performance, labor standards and corporate governance, which it views as important in its assessment of a company’s risk and potential for profitability. Common Stocks. Convertible Securities. combination of the features of several of these securities. Investment characteristics of convertible securities vary widely, which allows these securities to be employed for a variety of investment strategies. Investment Companies and Other Pooled Investment Vehicles. Illiquid and Restricted Securities. Swiss Real Estate Companies. Options Transactions. indices. The Fund may engage in these options transactions on an established Swiss exchange, European exchange (e.g., Eurex) or through privately negotiated transactions referred to as over-the-counter options. The Adviser may utilize options contracts to manage the Fund’s exposure to changing security prices. | |||||
| Risk Factors [Table Text Block] | Principal Risks The following summarizes the principal risks of an investment in the Fund: General Risks of Investing in the Fund Investment and Market Risk. Market Price Discount from Net Asset Value. Foreign Securities Risk. Equity Securities Risk. Convertible Securities Risk. either at a stated price or stated rate. Convertible securities have characteristics similar to both fixed income and equity securities. Convertible securities generally are subordinated to other similar but nonconvertible securities of the same issuer, although convertible bonds, as corporate debt obligations, enjoy seniority in right of payment to all equity securities, and convertible preferred stock is senior to common stock, of the same issuer. Illiquid and Restricted Securities Risk. The Fund also may be subject to a heightened liquidity risk in respect of its investments in private equity securities, including: (i) lack of a public market; (ii) dependence on an exit strategy, such as an initial public offering or sale of a business, which may not occur to realize the anticipated value of an investment or even dispose of the investment without a significant or total loss; and (iii) dependence on managerial assistance provided by other investors and the willingness of other investors or third parties to provide additional financial support to the issuer. Investing in Investment Companies and Other Pooled Investment Vehicles. Investing in private equity funds presents the additional risk that the Fund may have limited access to information concerning the underlying fund and its investments. For funds that are not listed on an exchange, the Adviser will fair value the Fund’s investment pursuant to procedures approved by the Fund’s Board of Directors. Although the Adviser will review the valuations provided by the funds, the Adviser may not be able to confirm independently the accuracy of such valuations. Swiss Real Estate Company Risk. equity and equity-linked securities, the Fund’s investments in Swiss Real Estate Companies will be linked to the performance of the Swiss real estate markets. The Fund will not generally invest in real estate directly, and will typically invest only in securities issued by Swiss Real Estate Companies. However, the Fund also is subject to the risks associated with the direct ownership of real estate. These risks include: (i) declines in the value of real estate; (ii) risks related to general and local economic conditions; (iii) overbuilding and extended vacancies of properties; (iv) increases in property taxes and operating expenses; (v) costs and liabilities associated with environmental problems; and (vi) casualty or condemnation losses. The yields available from investments in real estate depend on the amount of income and capital appreciation generated by the related properties. Property values may fall due to increasing vacancies or declining rents resulting from unanticipated economic, legal, cultural or technological developments. Performance of investments in REITs and REIT-like structures may decline as a result of the failure of borrowers to pay their loans and poor management. Income and real estate values also may be adversely affected by such factors as applicable laws, interest rate levels and the availability of financing. In addition, real estate investments are relatively illiquid and, therefore, the ability of real estate companies to vary their portfolios promptly in response to changes in economic or other conditions is limited. Options Risk. Leverage Risk. General Risks of Investing in Swiss Securities Swiss Securities Risk. by market developments in different ways than U.S. securities markets and may be more volatile than U.S. securities markets; (ii) political and economic risks with respect to Switzerland, including the possible imposition of, or changes in, currency exchange laws or other Swiss laws or restrictions applicable to investments in Swiss equities; and (iii) fluctuations in the rate of exchange between currencies and costs associated with currency conversion. Swiss Market and Concentration Risk. Disclosure Standards Risk. Foreign Currency and Exchange Rate Risk. exchange rate in effect on the day of its receipt by the Fund. If the value of the Swiss franc falls relative to the U.S. dollar between the date the Fund receives such income and the date it makes distributions, and, if the Fund has insufficient cash in U.S. dollars to meet distribution requirements, it may be required to liquidate securities in order to make distributions. There is no assurance that the Fund will be able to liquidate securities in order to meet such distribution requirements. Such liquidations, if required, also may adversely affect the Fund. Tax Risk. Additional Risk Considerations Cybersecurity Risk. Non-Diversified Status. Risk of Anti-Takeover Provisions. General Fund Investing Risks. | |||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||
| Capital Stock [Table Text Block] | Note 4—Capital Share Transactions The Fund is authorized to issue up to 50 million shares of capital stock. Transactions in capital shares were as follows: For the Year Ended For the Year Ended December 31, 2023 December 31, 2022 Shares Amount Shares Amount Dividends Reinvested — $ — — $ — Repurchased through Stock Repurchase Program (Note 6) (205,045 ) (1,687,724 ) (16,504 ) (120,928 ) Repurchased from Tender Offer (Note 7) — — — — Net Increase/(Decrease) (205,045 ) $ (1,687,724 ) (16,504 ) $ (120,928 ) | |||||
| Document Period End Date | Dec. 31, 2023 | |||||
| Investment and Market Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Investment and Market Risk. | |||||
| Market Price Discount from Net Asset Value [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Market Price Discount from Net Asset Value. | |||||
| Foreign Securities Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Foreign Securities Risk. | |||||
| Equity Securities Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Equity Securities Risk. | |||||
| Convertible Securities Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Convertible Securities Risk. either at a stated price or stated rate. Convertible securities have characteristics similar to both fixed income and equity securities. Convertible securities generally are subordinated to other similar but nonconvertible securities of the same issuer, although convertible bonds, as corporate debt obligations, enjoy seniority in right of payment to all equity securities, and convertible preferred stock is senior to common stock, of the same issuer. | |||||
| Illiquid and Restricted Securities Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Illiquid and Restricted Securities Risk. The Fund also may be subject to a heightened liquidity risk in respect of its investments in private equity securities, including: (i) lack of a public market; (ii) dependence on an exit strategy, such as an initial public offering or sale of a business, which may not occur to realize the anticipated value of an investment or even dispose of the investment without a significant or total loss; and (iii) dependence on managerial assistance provided by other investors and the willingness of other investors or third parties to provide additional financial support to the issuer. | |||||
| Investing in Investment Companies and Other Pooled Investment Vehicles [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Investing in Investment Companies and Other Pooled Investment Vehicles. Investing in private equity funds presents the additional risk that the Fund may have limited access to information concerning the underlying fund and its investments. For funds that are not listed on an exchange, the Adviser will fair value the Fund’s investment pursuant to procedures approved by the Fund’s Board of Directors. Although the Adviser will review the valuations provided by the funds, the Adviser may not be able to confirm independently the accuracy of such valuations. | |||||
| Swiss Real Estate Company Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Swiss Real Estate Company Risk. equity and equity-linked securities, the Fund’s investments in Swiss Real Estate Companies will be linked to the performance of the Swiss real estate markets. The Fund will not generally invest in real estate directly, and will typically invest only in securities issued by Swiss Real Estate Companies. However, the Fund also is subject to the risks associated with the direct ownership of real estate. These risks include: (i) declines in the value of real estate; (ii) risks related to general and local economic conditions; (iii) overbuilding and extended vacancies of properties; (iv) increases in property taxes and operating expenses; (v) costs and liabilities associated with environmental problems; and (vi) casualty or condemnation losses. The yields available from investments in real estate depend on the amount of income and capital appreciation generated by the related properties. Property values may fall due to increasing vacancies or declining rents resulting from unanticipated economic, legal, cultural or technological developments. Performance of investments in REITs and REIT-like structures may decline as a result of the failure of borrowers to pay their loans and poor management. Income and real estate values also may be adversely affected by such factors as applicable laws, interest rate levels and the availability of financing. In addition, real estate investments are relatively illiquid and, therefore, the ability of real estate companies to vary their portfolios promptly in response to changes in economic or other conditions is limited. | |||||
| Options Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Options Risk. | |||||
| Leverage Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Leverage Risk. | |||||
| Swiss Securities Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Swiss Securities Risk. by market developments in different ways than U.S. securities markets and may be more volatile than U.S. securities markets; (ii) political and economic risks with respect to Switzerland, including the possible imposition of, or changes in, currency exchange laws or other Swiss laws or restrictions applicable to investments in Swiss equities; and (iii) fluctuations in the rate of exchange between currencies and costs associated with currency conversion. | |||||
| Swiss Market and Concentration Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Swiss Market and Concentration Risk. | |||||
| Disclosure Standards Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Disclosure Standards Risk. | |||||
| Foreign Currency and Exchange Rate Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Foreign Currency and Exchange Rate Risk. exchange rate in effect on the day of its receipt by the Fund. If the value of the Swiss franc falls relative to the U.S. dollar between the date the Fund receives such income and the date it makes distributions, and, if the Fund has insufficient cash in U.S. dollars to meet distribution requirements, it may be required to liquidate securities in order to make distributions. There is no assurance that the Fund will be able to liquidate securities in order to meet such distribution requirements. Such liquidations, if required, also may adversely affect the Fund. | |||||
| Tax Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Tax Risk. | |||||
| Cybersecurity Risk [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Cybersecurity Risk. | |||||
| Non-Diversified Status [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Non-Diversified Status. | |||||
| Risk of Anti-Takeover Provisions [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | Risk of Anti-Takeover Provisions. | |||||
| General Fund Investing Risks [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Risk [Text Block] | General Fund Investing Risks. | |||||
| Common Shares [Member] | ||||||
| General Description of Registrant [Abstract] | ||||||
| Share Price | $ 8.20 | $ 8.20 | $ 7.56 | $ 9.94 | $ 8.94 | $ 8.41 |
| NAV Per Share | $ 9.76 | $ 9.76 | $ 8.80 | $ 11.50 | $ 10.45 | $ 9.71 |
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||
| Outstanding Security, Authorized [Shares] | 50,000,000 | |||||
| Outstanding Security, Not Held [Shares] | 12,990,705 |
