v3.25.2
N-2 - $ / shares
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
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, 2025            
Common Stock [Member]                
General Description of Registrant [Abstract]                
Share Price $ 47.86 $ 47.86 $ 45.69 $ 37.77 $ 33.39 $ 44.58 $ 32.64  
NAV Per Share $ 57.63 $ 57.63 $ 54.26 $ 46.49 $ 40.48 $ 48.87 $ 39.49 $ 38.42
Capital Stock, Long-Term Debt, and Other Securities [Abstract]                
Capital Stock [Table Text Block]  

3. Common Stock—During the six months ended June 30, 2025, the Corporation purchased 22,019 shares of its Common Stock at an average price of $42.48 per share, representing an average discount from net assets of 18.5%. 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, Held [Shares] 22,019              
Outstanding Security, Not Held [Shares] 28,913,659