Central Securities (CET) N-CSR 12 Feb 25 Certified annual shareholder report (management investment company) Financial data

N-2

N-2 - $ / shares		12 Months Ended
	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Prospectus [Line Items]
Document Period End Date		Dec. 31, 2024
Cover [Abstract]
Entity Central Index Key		0000018748
Amendment Flag		false
Document Type		N-CSR
Entity Registrant Name		Central Securities Corporation
General Description of Registrant [Abstract]
Investment Objectives and Practices [Text Block]		Investment Objective and Principal Investment Policies The Corporation’s investment objective is long-term growth of capital. Income received from investments is a secondary consideration. In pursuing its investment objective, the Corporation invests primarily in equity securities that it believes are undervalued at the time of purchase and have the potential for growth. It is Central’s goal to own companies that it believes will generate superior returns when compared with the broad market and preserve the Corporation’s capital in an inflationary environment. A guiding principle is the consideration of equity securities as units of ownership of a business and the purchase of them when the price appears to be low in relation to the value of the total enterprise. The Corporation’s objective may be changed without a vote of a majority of the Corporation’s voting securities. Central owns a limited number of companies, and it invests for the long-term. Honest management working in the interests of all shareholders is of the utmost importance in the appraisal of investments. The Corporation may sell securities for a variety of reasons, including excessive valuation, deteriorating results or to redeploy assets into more promising opportunities. The Corporation is not restricted as to the types of securities (e.g., equity, fixed income) in which it invests. The Corporation may invest in securities of issuers with any market capitalization. The Corporation is not required to be fully invested in securities and generally maintains a portion of its total assets in cash and securities considered to be cash equivalents. The Corporation has not adopted the practice of concentrating its investments in any particular industry or group of industries and does not contemplate changing its policy or restricting its field of investment. The Corporation is permitted to borrow money, subject to the limits of the Investment Company Act of 1940, as amended. These are fundamental policies and may not be changed without a vote of a majority of the Corporation’s voting securities. The Corporation also has fundamental policies relating to the issuance of senior securities, the underwriting of securities of other issuers, the purchase or sale of real estate, the purchase or sale of commodities or commodity contracts, and the making of loans. These policies may not be changed without a vote of a majority of the Corporation’s voting securities. The Corporation has a non-fundamental policy permitting it to engage in the writing, sale and purchase of options and may make short sales. The Corporation has not utilized these policies in recent years and does not contemplate using any one of them in an amount greater than 5% of the Corporation’s assets unless stockholders are notified of such intention at least 60 days in advance.
Risk Factors [Table Text Block]		Principal Risks As with any investment, you could lose all or part of your investment in the Corporation, and the Corporation’s investment performance could trail that of other investments. Investment in the Corporation is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Corporation’s net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. An investment in the Corporation is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Corporation has a substantial portion of its assets invested in the common stock of The Plymouth Rock Company, a privately issued, illiquid security. The investment in Plymouth Rock is subject to many of the risks described further below. Market Risk.  and crises. Active Management Risk.  possible prices. Non-Diversification Risk.  Corporation’s NAV. Sector Risk.  a whole. ​Illiquid Investments Risk.  investment opportunities. Privately Issued Securities Risk.  the Corporation. Valuation Risk.  Corporation’s shares. Market Price of Shares Risk.  their NAV. The Corporation cannot predict whether its listed stock will trade at, below or above NAV. Market price risk is a risk separate and distinct from the risk that the Corporation’s NAV will decrease. The Corporation’s shares have generally traded at a discount to the Corporation’s NAV. In addition to NAV, the market price of shares may be affected by such factors as the Corporation’s dividend and distribution levels and stability, market liquidity, market supply and demand, unrealized gains, general market and economic conditions, and other factors. Leverage Risk.  as “leverage.” The use of leverage creates certain risks for the Corporation’s stockholders, including the greater likelihood of higher volatility of the Corporation’s return, its NAV and the market price of its Common Stock. To the extent the income or capital appreciation derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Corporation’s return will be greater than if leverage had not been used. Conversely, if the income or capital appreciation from the securities purchased with such funds is not sufficient to cover the cost of leverage or if the Corporation incurs capital losses, the return of the Corporation will be less than if leverage had not been used, and therefore the amount available for distribution to shareholders could be reduced or potentially eliminated. The Corporation also may be required to sell investments in order to make interest or principal payments on borrowings used for leverage when it may be disadvantageous to do so. Stockholder Concentration Risk.  asset value. Dependence on Key Personnel Risk.  the Corporation. Cybersecurity Risk.  lose value. Status as a Regulated Investment Company.  investment performance.
Market Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Market Risk.  and crises.
Active Management Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Active Management Risk.  possible prices.
Non-Diversification Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Non-Diversification Risk.  Corporation’s NAV.
Sector Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Sector Risk.  a whole.
Illiquid Investments Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		​Illiquid Investments Risk.  investment opportunities.
Privately Issued Securities Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Privately Issued Securities Risk.  the Corporation.
Valuation Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Valuation Risk.  Corporation’s shares.
Market Price of Shares Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Market Price of Shares Risk.  their NAV. The Corporation cannot predict whether its listed stock will trade at, below or above NAV. Market price risk is a risk separate and distinct from the risk that the Corporation’s NAV will decrease. The Corporation’s shares have generally traded at a discount to the Corporation’s NAV. In addition to NAV, the market price of shares may be affected by such factors as the Corporation’s dividend and distribution levels and stability, market liquidity, market supply and demand, unrealized gains, general market and economic conditions, and other factors.
Leverage Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Leverage Risk.  as “leverage.” The use of leverage creates certain risks for the Corporation’s stockholders, including the greater likelihood of higher volatility of the Corporation’s return, its NAV and the market price of its Common Stock. To the extent the income or capital appreciation derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Corporation’s return will be greater than if leverage had not been used. Conversely, if the income or capital appreciation from the securities purchased with such funds is not sufficient to cover the cost of leverage or if the Corporation incurs capital losses, the return of the Corporation will be less than if leverage had not been used, and therefore the amount available for distribution to shareholders could be reduced or potentially eliminated. The Corporation also may be required to sell investments in order to make interest or principal payments on borrowings used for leverage when it may be disadvantageous to do so.
Stockholder Concentration Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Stockholder Concentration Risk.  asset value.
Dependence on Key Personnel Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Dependence on Key Personnel Risk.  the Corporation.
Cybersecurity Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Cybersecurity Risk.  lose value.
Status as a Regulated Investment Company [Member]
General Description of Registrant [Abstract]
Risk [Text Block]		Status as a Regulated Investment Company.  investment performance.
Common Stock [Member]
General Description of Registrant [Abstract]
Share Price	$ 45.69	$ 45.69	$ 37.77	$ 33.39	$ 44.58	$ 32.64
NAV Per Share	$ 54.26	$ 54.26	$ 46.49	$ 40.48	$ 48.87	$ 39.49	$ 38.42
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Outstanding Security, Authorized [Shares]	40,000,000
Outstanding Security, Not Held [Shares]	28,935,676