v3.25.4
Cover - USD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Mar. 10, 2026
Jun. 30, 2025
Document Type 10-K      
Amendment Flag false      
Document Annual Report true      
Document Transition Report false      
Document Period End Date Dec. 31, 2025      
Document Fiscal Period Focus FY      
Document Fiscal Year Focus 2025      
Current Fiscal Year End Date --12-31      
Entity File Number 814-00852      
Entity Registrant Name SuRo Capital Corp.      
Entity Central Index Key 0001509470      
Entity Tax Identification Number 27-4443543      
Entity Incorporation, State or Country Code MD      
Entity Address, Address Line One 640 Fifth Avenue      
Entity Address, Address Line Two 12th Floor      
Entity Address, City or Town New York      
Entity Address, State or Province NY      
Entity Address, Postal Zip Code 10019      
City Area Code (212)      
Local Phone Number 931-6331      
Entity Well-known Seasoned Issuer No      
Entity Voluntary Filers No      
Entity Current Reporting Status Yes      
Entity Interactive Data Current Yes      
Entity Filer Category Non-accelerated Filer      
Entity Small Business false      
Entity Emerging Growth Company false      
Entity Shell Company false      
Entity Public Float       $ 179,919,391
Entity Common Stock, Shares Outstanding     25,387,756  
Documents Incorporated by Reference [Text Block] Portions of the Registrant’s definitive proxy statement relating to the Registrant’s 2026 annual meeting of stockholders (the “2026 Proxy Statement”), to be filed with the Securities and Exchange Commission (the “SEC”) within 120 days following the end of the Registrant’s fiscal year, are incorporated by reference in Part III of this annual report on Form 10-K as indicated herein.      
ICFR Auditor Attestation Flag false      
Document Financial Statement Error Correction [Flag] false      
Entity Listing, Par Value Per Share $ 0.01      
Auditor Firm ID 199 688    
Auditor Opinion [Text Block] We have audited the accompanying consolidated statements of assets and liabilities of SuRo Capital Corp. and Subsidiaries (the “Company”) including the consolidated schedule of investments as of December 31, 2025, the related consolidated statements of operations, cash flows, and changes in net assets for the year ended December 31, 2025, the financial highlights (presented in Note 8) for the year then ended, and the related notes (collectively referred to as the “financial statements”). In our opinion, the financial statements and financial highlights present fairly, in all material respects, the financial position of the Company as of December 31, 2025, and the results of its operations and its cash flows for the year ended December 31, 2025 and the financial highlights for the year then ended in conformity with accounting principles generally accepted in the United States of America.      
Auditor Name CBIZ CPAs P.C Marcum LLP    
Auditor Location Boston, MA Boston, MA    
Common Stock, par value $0.01 per share        
Title of 12(b) Security Common Stock, par value $0.01 per share      
Trading Symbol SSSS      
Security Exchange Name NASDAQ      
6.00% Notes due 2026        
Title of 12(b) Security 6.00% Notes due 2026      
Trading Symbol SSSSL      
Security Exchange Name NASDAQ