Quarterly report pursuant to Section 13 or 15(d)

SHARE-BASED COMPENSATION - Restricted Stock Authorized and Available for Issuance (Details)

v3.22.2.2
SHARE-BASED COMPENSATION - Restricted Stock Authorized and Available for Issuance (Details) - Restricted Stock
9 Months Ended
Sep. 30, 2022
shares
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) (10,256)
Restricted stock available for issuance (in shares) 4,989,744
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