v3.25.4

FAIR VALUE MEASUREMENTS - Valuation Techniques and Significant Level 3 Inputs (Details) $ in Thousands | Dec. 31, 2025 USD ($) | Mar. 31, 2025 USD ($)
--- | --- | ---
Fair Value |  |  |  |
Investments at fair value | $ 2,013,205 | [1],[2],[3],[4],[5] | $ 1,785,299 | [6],[7],[8],[9],[10]
First lien loans |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 1,812,469 |  | 1,586,622 |
Second lien loans |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 16,850 |  | 18,066 |
Subordinated debt |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 1,139 |  | 1,218 |
Preferred equity |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 69,048 |  | 102,918 |
Common equity & warrants |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 109,957 |  | 76,475 |
Earnout |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 3,742 |  |  |
Significant Unobservable Inputs (Level 3) |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 2,013,205 |  | 1,785,299 |
Significant Unobservable Inputs (Level 3) | First lien loans |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 1,812,469 |  | 1,586,622 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Discount Rate |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 1,631,437 |  | 1,448,656 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Third Party Broker Quote |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 1,081 |  | $ 6,923 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.043 |  | 0.052 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Minimum | Third Party Broker Quote |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.404 |  | 0.400 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.686 |  | 0.647 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Maximum | Third Party Broker Quote |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.404 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.119 |  | 0.128 |
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Weighted Average | Third Party Broker Quote |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.404 |  | 0.798 |
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 151,002 |  | $ 125,500 |
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach | Minimum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.913 |  | 0.898 |
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach | Maximum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.993 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach | Weighted Average | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.991 |  | 0.979 |
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 28,949 |  | $ 5,543 |
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.127 |  | 0.210 |
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 9.0 |  | 3.0 |
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.226 |  | 0.492 |
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 11.0 |  | 9.0 |
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.181 |  | 0.210 |
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 10.0 |  | 3.0 |
Significant Unobservable Inputs (Level 3) | Second lien loans |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 16,850 |  | $ 18,066 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 16,850 |  |  |
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Discount Rate |  |  |  |
Fair Value |  |  |  |
Investments at fair value |  |  | $ 18,066 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.138 |  | 0.095 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 1.718 |  | 0.412 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.248 |  | 0.133 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 0 |  | $ 0 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.282 |  | 0.210 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 2.0 |  | 3.0 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.282 |  | 0.210 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 2.0 |  | 3.0 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.000 |  | 0.000 |
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.0 |  | 0.0 |
Significant Unobservable Inputs (Level 3) | Subordinated debt |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 1,139 |  | $ 1,218 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Discount Rate |  |  |  |
Fair Value |  |  |  |
Investments at fair value | 524 |  | 538 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Third Party Broker Quote |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 58 |  | $ 58 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.164 |  | 0.144 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Minimum | Third Party Broker Quote |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.254 |  | 0.250 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.164 |  | 0.144 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Maximum | Third Party Broker Quote |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.254 |  | 0.250 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.164 |  | 0.144 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Weighted Average | Third Party Broker Quote |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.254 |  | 0.250 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value |  |  | $ 65 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach | Minimum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs |  |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach | Maximum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs |  |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach | Weighted Average | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs |  |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 557 |  | $ 557 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.145 |  | 0.133 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 6.2 |  | 6.1 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.174 |  | 0.176 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 7.8 |  | 7.6 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.154 |  | 0.147 |
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 6.7 |  | 6.6 |
Significant Unobservable Inputs (Level 3) | Preferred equity |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 69,048 |  | $ 102,918 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 500 |  | $ 2,900 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach | Minimum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 1.000 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach | Maximum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 1.000 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach | Weighted Average | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 1.000 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 68,548 |  | $ 100,018 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.115 |  | 0.111 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 2.0 |  | 3.0 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.477 |  | 0.492 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 17.2 |  | 16.9 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.168 |  | 0.159 |
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 7.7 |  | 8.8 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 109,957 |  | $ 76,475 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 1,650 |  | $ 1,597 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach | Minimum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 1.000 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach | Maximum | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 1.000 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach | Weighted Average | Cost |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 1.000 |  | 1.000 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 108,307 |  | $ 74,878 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.106 |  | 0.119 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 2.0 |  | 3.0 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.304 |  | 0.233 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 16.5 |  | 16.0 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.139 |  | 0.144 |
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 9.0 |  | 8.4 |
Significant Unobservable Inputs (Level 3) | Earnout |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 3,742 |  |  |
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach |  |  |  |
Fair Value |  |  |  |
Investments at fair value | $ 3,742 |  |  |
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach | Minimum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.333 |  |  |
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach | Maximum | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.333 |  |  |
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach | Weighted Average | Discount Rate |  |  |  |
Significant Unobservable Inputs |  |  |  |
Significant Level 3 Inputs | 0.333 |  |  |
[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 December 31, 2025, the Company held $1,607.8 million of non-control/non-affiliate investments, which represented approximately 79.9% of the Company’s investment assets. The fair value of these investments as a percent of net assets is 161.4%.
[3] | 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.
[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.

X
- Definition Investments​ Fair​ Value ​Disclosure, Measurement Input [Abstract] + References No definition available. + Details
Name: | cswc_InvestmentsFairValueDisclosureMeasurementInputAbstract
Namespace Prefix: | cswc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of input used to measure investment owned by investment company. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_InvestmentCompanyInvestmentOwnedFairValueMeasurementInput
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value of investment in security owned. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(11)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-6 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 55 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477439/946-210-55-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-6 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-1 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-2 Reference 11: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479168/946-830-55-12 Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-6 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(d)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(2)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(2)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column C)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-1 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column A)(Footnote 1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-1 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column C)(Footnote 5)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-1 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column C)(Footnote 6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-1 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column C)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column C)(Footnote 2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column A)(Footnote 6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column A)(Footnote 7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column C)(Footnote 9)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column F)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column A)(Footnote 1)(b)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column A)(Footnote 1)(b)(5)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column F)(Footnote 4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column F)(Footnote 7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 + Details
Name: | us-gaap_InvestmentOwnedAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=cswc_DebtSecuritiesFirstLienMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=cswc_DebtSecuritiesSecondLienMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_SubordinatedDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_PreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=cswc_CommonEquityWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=cswc_EarnoutMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_IncomeApproachValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDiscountRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputQuotedPriceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_MarketApproachValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=cswc_MeasurementInputCostMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=cswc_ValuationEnterpriseValueWaterfallApproachMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputEbitdaMultipleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |