SHARE-BASED COMPENSATION - Restricted Stock Authorized and Available for Issuance (Details) - Restricted Stock |
12 Months Ended |
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Dec. 31, 2022
shares
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| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | |
| Less net restricted stock granted (in shares) | (499,274) |
| Main Street Capital Corporation 2022 Equity and Incentive Plan | |
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | |
| Restricted stock authorized under the plan (in shares) | 5,000,000 |
| Less net restricted stock granted (in shares) | (14,245) |
| Restricted stock available for issuance (in shares) | 4,985,755 |
| Main Street Capital Corporation 2022 Non-Employee Director Restricted Stock Plan | Director | |
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | |
| Restricted stock authorized under the plan (in shares) | 300,000 |
| Less net restricted stock granted (in shares) | (4,590) |
| Restricted stock available for issuance (in shares) | 295,410 |
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Number of shares authorized for issuance under share-based payment arrangement. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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