NATURE OF OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details)	3 Months Ended	9 Months Ended		12 Months Ended									141 Months Ended
	Mar. 31, 2023 USD ($) shares	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 USD ($) shares	Dec. 31, 2012 USD ($) shares	Sep. 30, 2023 USD ($) shares
Nature of Operation And Significant Accounting Policies [Line Items]
Issuance of common stock, net of offering costs (shares) | shares	581,614			149,174	31,592	354,257	3,177,936	7,931	3,465,922	380,936	63,998	12,035,023	24,125,642
Gross Proceeds	$ 8,418,160			$ 2,070,935	$ 449,515	$ 5,023,843	$ 45,862,995	$ 93,737	$ 48,741,406	$ 5,485,780	$ 899,964	$ 180,522,093	$ 352,021,616
Proceeds for offering expenses and sales load fees													11,022,607
Offering expenses reimbursements													672,917
Proceeds from the issuance of common stock		$ 63,348,436	$ 420,004										341,671,926
Credit Facility payable		$ 161,192,612		197,685,281									$ 161,192,612
Asset coverage ratio		221											221
Cash balance		$ 389,676											$ 389,676
Cash exceeding the insured amount		139,676											139,676
Cash equivalents and carried at cost		18,821,045											18,821,045
Cash held in foreign currency		276											276
Cash held in foreign currency at acquisition cost		288
SBA-guaranteed Debentures
Nature of Operation And Significant Accounting Policies [Line Items]
Estimated fair values		291,023,000											291,023,000
2026 Notes
Nature of Operation And Significant Accounting Policies [Line Items]
Estimated fair values		89,061,000											89,061,000
SBIC Subsidiary | SBA-guaranteed Debentures
Nature of Operation And Significant Accounting Policies [Line Items]
Maximum borrowing capacity		150,000,000											150,000,000
Regulatory capital		75,000,000		75,000,000									75,000,000
Credit Facility payable		150,000,000		150,000,000									150,000,000
SBIC II Subsidiary | SBA-guaranteed Debentures
Nature of Operation And Significant Accounting Policies [Line Items]
Maximum borrowing capacity		175,000,000											175,000,000
Regulatory capital		$ 87,500,000		$ 87,500,000									$ 87,500,000