v3.26.1
FAIR VALUE MEASUREMENTS - Schedule of Investment Portfolio by Level (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Mar. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value $ 2,097,446 [1],[2],[3],[4],[5] $ 1,785,299 [6],[7],[8],[9],[10]
Total Investments 2,097,446 1,785,299
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total Investments 0 0
Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total Investments 0 0
Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 2,097,446 1,785,299
Total Investments 2,097,446 1,785,299
First lien loans    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 1,890,406 1,586,622
First lien loans | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
First lien loans | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
First lien loans | Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 1,890,406 1,586,622
Second lien loans    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 24,931 18,066
Second lien loans | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Second lien loans | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Second lien loans | Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 24,931 18,066
Subordinated debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 1,157 1,218
Subordinated debt | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Subordinated debt | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Subordinated debt | Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 1,157 1,218
Preferred equity    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 74,638 102,918
Preferred equity | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Preferred equity | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Preferred equity | Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 74,638 102,918
Common equity & warrants    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 102,276 76,475
Common equity & warrants | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Common equity & warrants | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0 0
Common equity & warrants | Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 102,276 $ 76,475
Earnout    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 4,038  
Earnout | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0  
Earnout | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value 0  
Earnout | Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment owned, fair value $ 4,038  
[1] All debt investments are income-producing, unless otherwise noted. Equity investments are non-income producing, unless otherwise noted.
(2)All of the Company’s investments and the investments of Capital Southwest SPV LLC ("SPV"), SBIC I (as defined below) and SBIC II (as defined below) are pledged as collateral for the Company’s senior secured revolving credit facility, the SPV's financing credit facility or in support of the SBA-guaranteed debentures to be issued by Capital Southwest SBIC I, LP ("SBIC I") and Capital Southwest SBIC II, LP ("SBIC II"), the Company's wholly-owned subsidiaries that operate as small business investment companies, respectively.
[2] Non-Control/Non-Affiliate investments are generally defined by the 1940 Act as investments that are neither control investments nor affiliate investments. Investments are classified as non-control/non-affiliate investments, unless otherwise noted. At March 31, 2026, the Company held $1,682.4 million of non-control/non-affiliate investments, which represented approximately 80.2% of the Company’s investment assets. The fair value of these investments as a percent of net assets is 166.5%.
[3] The Company's investment portfolio is comprised entirely of debt and equity securities, along with other financial instruments, of privately held companies for which quoted prices falling within the categories of Level 1 and Level 2 inputs are not readily available. Therefore, the Company values all of its portfolio investments at fair value, as determined in good faith by the valuation committee comprised of certain officers of the Company (the "Valuation Committee") as the valuation designee of the Board of Directors (the "Valuation Designee") pursuant to Rule 2a-5 under the Investment Company Act of 1940, as amended (the “1940 Act”), using significant unobservable Level 3 inputs. Refer to Note 4 - Fair Value Measurements for further discussion.
[4] Equity ownership may be held in shares or units of a company that is either wholly owned by the portfolio company or under common control by the same parent company to the portfolio company.
[5] Unless otherwise noted, all portfolio company headquarters are based in the United States.
[6] All debt investments are income-producing, unless otherwise noted. Equity investments are non-income producing, unless otherwise noted.
[7] Non-Control/Non-Affiliate investments are generally defined by the 1940 Act as investments that are neither control investments nor affiliate investments. Investments are classified as non-control/non-affiliate investments, unless otherwise noted. At March 31, 2025, the Company held $1,436.3 million of non-control/non-affiliate investments, which represented approximately 80.5% of the Company’s investment assets. The fair value of these investments as a percent of net assets is 162.6%.
[8] The Company's investment portfolio is comprised entirely of debt and equity securities of privately held companies for which quoted prices falling within the categories of Level 1 and Level 2 inputs are not readily available. Therefore, the Company values all of its portfolio investments at fair value, as determined in good faith by the valuation committee comprised of certain officers of the Company (the "Valuation Committee") as the valuation designee of the Board of Directors (the "Valuation Designee") pursuant to Rule 2a-5 under the Investment Company Act of 1940, as amended (the “1940 Act”), using significant unobservable Level 3 inputs. Refer to Note 4 - Fair Value Measurements for further discussion.
[9] Equity ownership may be held in shares or units of a company that is either wholly owned by the portfolio company or under common control by the same parent company to the portfolio company.
[10] Unless otherwise noted, all portfolio company headquarters are based in the United States.