Organization and Nature of Business	3 Months Ended
Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Business	Note 1. Organization and Nature of Business Fidus Investment Corporation (“FIC,” and together with its subsidiaries, the “Company”), a Maryland corporation, operates as an externally managed, closed-end, non-diversified business development company (“BDC”) under the Investment Company Act of 1940, as amended (“1940 Act”). FIC completed its initial public offering, or IPO, in June 2011. In addition, for U.S. federal income tax purposes, the Company has elected, and intends to qualify annually, to be treated as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). The Company provides customized debt and equity financing solutions to lower middle-market companies, and may make investments directly or through its two wholly-owned investment company subsidiaries, Fidus Mezzanine Capital II, L.P. (“Fund II”) and Fidus Mezzanine Capital III, L.P. (“Fund III”). Fund III is licensed by the U.S. Small Business Administration (the “SBA”) as a small business investment company (“SBIC”). The SBIC license allows Fund III to obtain leverage by issuing SBA-guaranteed debentures (“SBA debentures”), subject to the issuance of leverage commitments by the SBA and other customary procedures. As a SBIC, Fund III is subject to regulations of and oversight by the SBA under the Small Business Investment Act of 1958, as amended (the “SBIC Act”), concerning, among other things, the size and nature of the companies in which they may invest and the structure of those investments. Fund II completed its wind-down plan, can no longer issue additional SBA debentures, and relinquished its SBIC license on March 7, 2024, which remains subject to the SBA's approval. We believe that utilizing both FIC and Fund III as investment vehicles provides us with access to a broader array of investment opportunities. Given our access to lower cost capital through the SBA’s SBIC debenture program, we expect that we will continue to make investments through Fund III until the earlier of the end of Fund III's investment period, if applicable, or Fund III reaches their borrowing limit under the SBA program. For two or more SBICs under common control, the maximum amount of outstanding SBA debentures cannot exceed $350,000. Fund II and Fund III are not registered under the 1940 Act and rely on the exclusion from the definition of investment company contained in Section 3(c)(7) of the 1940 Act. The Company pays a quarterly base management fee and an incentive fee to Fidus Investment Advisors, LLC, our investment advisor (the “Investment Advisor” or “Fidus Investment Advisors”) under an investment advisory agreement (the “Investment Advisory Agreement”).

Organization and Nature of Business

3 Months Ended

Mar. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Note 1. Organization and Nature of Business

Fidus Investment Corporation (“FIC,” and together with its subsidiaries, the “Company”), a Maryland corporation, operates as an externally managed, closed-end, non-diversified business development company (“BDC”) under the Investment Company Act of 1940, as amended (“1940 Act”). FIC completed its initial public offering, or IPO, in June 2011. In addition, for U.S. federal income tax purposes, the Company has elected, and intends to qualify annually, to be treated as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”).

The Company provides customized debt and equity financing solutions to lower middle-market companies, and may make investments directly or through its two wholly-owned investment company subsidiaries, Fidus Mezzanine Capital II, L.P. (“Fund II”) and Fidus Mezzanine Capital III, L.P. (“Fund III”). Fund III is licensed by the U.S. Small Business Administration (the “SBA”) as a small business investment company (“SBIC”). The SBIC license allows Fund III to obtain leverage by issuing SBA-guaranteed debentures (“SBA debentures”), subject to the issuance of leverage commitments by the SBA and other customary procedures. As a SBIC, Fund III is subject to regulations of and oversight by the SBA under the Small Business Investment Act of 1958, as amended (the “SBIC Act”), concerning, among other things, the size and nature of the companies in which they may invest and the structure of those investments. Fund II completed its wind-down plan, can no longer issue additional SBA debentures, and relinquished its SBIC license on March 7, 2024, which remains subject to the SBA's approval.

We believe that utilizing both FIC and Fund III as investment vehicles provides us with access to a broader array of investment opportunities. Given our access to lower cost capital through the SBA’s SBIC debenture program, we expect that we will continue to make investments through Fund III until the earlier of the end of Fund III's investment period, if applicable, or Fund III reaches their borrowing limit under the SBA program. For two or more SBICs under common control, the maximum amount of outstanding SBA debentures cannot exceed $350,000.

Fund II and Fund III are not registered under the 1940 Act and rely on the exclusion from the definition of investment company contained in Section 3(c)(7) of the 1940 Act.

The Company pays a quarterly base management fee and an incentive fee to Fidus Investment Advisors, LLC, our investment advisor (the “Investment Advisor” or “Fidus Investment Advisors”) under an investment advisory agreement (the “Investment Advisory Agreement”).