Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)			1 Months Ended	12 Months Ended
	Dec. 30, 2025	Jan. 24, 2025	Nov. 30, 2019	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Apr. 23, 2025
Summary of Significant Accounting Policies [Line Items]
Minimum percentage of total assets in qualifying assets				70.00%	70.00%
Common shares, issued				3,037,709	2,648,916
Common shares, outstanding				2,969,814	2,581,021
Aggregate amortized cost of debt investments on non accrual status				$ 16,300,000
Aggregate fair value of debt investments on non accrual status				6,700,000
Reserve for possible losses of interest receivable				$ 25,337
Percentage of investments in non accrual status at amortized cost				28.60%
Percentage of investments in non accrual status at fair value				13.70%
Percentage of total investment income attributable to non-cash PIK interest income				33.20%	23.10%	16.70%
Fee income related to amortization of financing fees				$ 248,844	$ 209,316	$ 205,480
Estimated fees income related to amortization of financing fees year one				145,000
Estimated fees income related to amortization of financing fees year two				122,000
Estimated fees income related to amortization of financing fees year three				72,000
Board and monitoring fees earned				37,584	92,393	52,000
Non-recurring fees income				199,453	232,011	63,264
Original issue discount income				41,404	28,008	21,008
Estimated original issue discount income in next year				14,000
Amortization expense				25,000	25,000	25,000
Estimated amortization of deferred financing fees year one				25,000
Estimated Amortization of Deferred Financing Fee Year Two				12,500
Income taxes paid				(3,126)	121,433	645,248
Interest paid				92,526	1,154,059	934,638
Interest receivable and PIK interest into debt investments				2,149,390	1,980,728	1,225,773
Declaration of common stock dividend					8,672,231
Interest receivable into investments				$ 2,149,390	$ 1,980,728	1,225,773
Preferred stock authorized				500,000	500,000
Preferred stock, par value				$ 10	$ 10
Federal excise tax expense				$ 40,997	$ 37,388	$ 52,800
Percentage of excise tax				4.00%
Accounting Standards Update [Extensible Enumeration]				us-gaap:AccountingStandardsUpdate202309Member
Change in accounting principle, accounting standards update, adopted				true
Change in accounting principle, accounting standards update, adoption date				Jan. 01, 2025
Change in accounting principle, accounting standards update, immaterial effect				true
O 2024 Q4 Dividends
Summary of Significant Accounting Policies [Line Items]
Dividend per share		$ 4.2
Percentage of dividend paid in cash		20.00%
Percentage of dividend paid in shares		80.00%
Dividend record date		Dec. 16, 2024
Dividend payable date		Jan. 24, 2025
O 2025 Q4 Dividends
Summary of Significant Accounting Policies [Line Items]
Dividend per share	$ 0.29
Dividend record date	Dec. 16, 2025
Dividend payable date	Dec. 30, 2025
Common Stock
Summary of Significant Accounting Policies [Line Items]
Authorized repurchase amount							$ 1,500,000
Repurchase of common stock				0	0
Minimum
Summary of Significant Accounting Policies [Line Items]
Percentage of distribution of annually to shareholders of its ordinary net income and realized net short-term capital gains in excess of realized net long-term capital losses				90.00%
Control investments voting securities				25.00%
Control investments voting securities percentage on Board				50.00%
Affiliate investments voting securities				5.00%
Maximum
Summary of Significant Accounting Policies [Line Items]
Affiliate investments voting securities				25.00%
East Asset Management
Summary of Significant Accounting Policies [Line Items]
Stock sale transaction cost			$ 25,000,000
Common stock issued			8,300,000
Contribution received In form of cash			$ 15,500,000
Contribution received in form of portfolio assets			$ 9,500,000

RAND CAPITAL CORP 10-K/A