Annual report [Section 13 and 15(d), not S-K Item 405]

Document and Entity Information

Document and Entity Information - USD ($)	4 Months Ended	8 Months Ended	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2025	Sep. 10, 2025	Dec. 31, 2025	Mar. 05, 2026	Jun. 30, 2025
Cover [Abstract]
Document Type			10-K/A
Amendment Flag			true
Amendment Description			EXPLANATORY NOTERand Capital Corporation (the “Corporation”) is filing this Amendment No. 1 (this “Amendment”) to its Annual Report on Form 10-K for the fiscal year ended December 31, 2025 (the “2025 Form 10-K”) solely for the purpose of adding the “Report of Independent Registered Public Accounting Firm” issued by Freed Maxick P.C. (f/k/a Freed Maxick CPAs, P.C.) with respect to its audit of the financial statements of the Corporation as of December 31, 2024 and for each of the two years in the period ended December 31, 2024 (the “Report of the Predecessor Auditor”). As previously described in a Current Report on Form 8-K, on September 11, 2025, the Corporation replaced Freed Maxick P.C. as the Corporation’s independent registered public accounting firm with WithumSmith+Brown, PC, due to the acquisition of certain assets of Freed Maxick P.C. by WithumSmith+Brown, PC.The Report of the Predecessor Auditor was inadvertently omitted from the 2025 Form 10-K. Other than as described above, no other changes have been made to the 2025 Form 10-K, including with respect to the financial statements of the Corporation included in the 2025 Form 10-K.This Amendment does not reflect events occurring after the filing of the 2025 Form 10-K, does not update disclosures contained in the 2025 Form 10-K and does not modify or amend the 2025 Form 10-K except as specifically described above. Pursuant to Rule 12b-15 of the Securities Exchange Act of 1934, as amended, this Amendment contains the complete text of each Item that is amended and certifications of the Company’s Principal Executive Officer and Principal Financial Officer required under Items 302 and 906 of the Sarbanes-Oxley Act of 2002, as amended, dated as of the date of this Amendment, as well as updated inline XBRL exhibits.
Document Period End Date			Dec. 31, 2025
Document Fiscal Year Focus			2025
Document Fiscal Period Focus			FY
Trading Symbol			RAND
Entity Registrant Name			Rand Capital Corporation
Entity Well-known Seasoned Issuer			No
Entity Central Index Key			0000081955
Entity Current Reporting Status			Yes
Entity Voluntary Filers			No
Entity Interactive Data Current			Yes
Current Fiscal Year End Date			--12-31
Entity Filer Category			Non-accelerated Filer
Entity Small Business			false
Entity Shell Company			false
Entity Emerging Growth Company			false
Entity Public Float					$ 15,230,000
Entity Common Stock, Shares Outstanding				2,969,814
Title of 12(b) Security			Common Stock, $0.10 par value
Security Exchange Name			NASDAQ
Entity File Number			814-00235
Entity Incorporation, State or Country Code			NY
Entity Tax Identification Number			16-0961359
Entity Address, Address Line One			1405 Rand Building
Entity Address, City or Town			Buffalo
Entity Address, State or Province			NY
Entity Address, Postal Zip Code			14203
ICFR Auditor Attestation Flag			false
City Area Code			716
Local Phone Number			853-0802
Document Annual Report			true
Document Transition Report			false
Document Financial Statement Error Correction [Flag]			false
Auditor Firm ID	317	100
Auditor Location	Buffalo, New York	Buffalo, New York
Auditor Name	Withum Smith+Brown, PC	FREED MAXICK P.C. (F/K/A Freed Maxick CPAs, P.C.)
Auditor Opinion			Opinion on the Consolidated Financial Statements We have audited the accompanying consolidated statement of financial position, including the consolidated schedule of portfolio investments, of Rand Capital Corporation and Subsidiaries (the Corporation) as of December 31, 2025, and the related consolidated statements of operations, changes in net assets, financial highlights and cash flows for the year ended December 31, 2025, and the related notes to the consolidated financial statements (collectively, the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of Rand Capital Corporation and Subsidiaries as of December 31, 2025, and the results of its operations, its cash flows and financial highlights for the year ended December 31, 2025 in conformity with accounting principles generally accepted in the United States of America. Opinion on the Financial Statements We have audited the accompanying consolidated statement of financial position, including the consolidated schedule of portfolio investments, of Rand Capital Corporation and Subsidiaries (the Corporation) as of December 31, 2024, and the related consolidated statements of operations, changes in net assets and cash flows and the related notes to the consolidated financial statements for each of the two years in the period ended December 31, 2024, and the financial highlights schedule for each of the four years in the period ended December 31, 2024 (collectively, the financial statements). In our opinion, the financial statements and financial highlights schedule present fairly, in all material respects, the financial position of Rand Capital Corporation and Subsidiaries as of December 31, 2024, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2024, and the financial highlights for each of the four years in the period ended December 31, 2024 in conformity with accounting principles generally accepted in the United States of America.
Documents Incorporated by Reference			DOCUMENTS INCORPORATED BY REFERENCE Portions of the Corporation’s definitive proxy statement for the 2026 Annual Meeting of Shareholders are incorporated by reference into Part III of this report.