N-2 - $ / shares |
6 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2026 |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Cover [Abstract] | ||||||||
| Entity Central Index Key | 0000018748 | |||||||
| Amendment Flag | false | |||||||
| Document Type | N-CSRS | |||||||
| Entity Registrant Name | Central Securities Corporation | |||||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||||
| Document Period End Date | Jun. 30, 2026 | |||||||
| Common Stock [Member] | ||||||||
| General Description of Registrant [Abstract] | ||||||||
| Share Price | $ 52.45 | $ 52.45 | $ 50.71 | $ 45.69 | $ 37.77 | $ 33.39 | $ 44.58 | |
| NAV Per Share | $ 62.11 | $ 62.11 | $ 60.50 | $ 54.26 | $ 46.49 | $ 40.48 | $ 48.87 | $ 39.49 |
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||||
| Capital Stock [Table Text Block] | 3. Common Stock—During the six months ended June 30, 2026, the Corporation did not purchase any shares of its Common Stock. The Corporation may from time to time purchase its Common Stock in such amounts and at such prices as the Board of Directors may deem advisable in the best interests of the stockholders. Purchases will only be made at prices less than net asset value per share, thereby increasing the net asset value of shares held by the remaining stockholders. Shares so acquired may be held as treasury stock available for stock distributions, or may be retired. |
|||||||
| Outstanding Security, Authorized [Shares] | 40,000,000 | |||||||
| Outstanding Security, Not Held [Shares] | 29,549,265 |