Annual report pursuant to Section 13 and 15(d)

RELATED PARTY TRANSACTIONS (Details)

v3.24.0.1
RELATED PARTY TRANSACTIONS (Details)
 1 Months Ended 12 Months Ended
Nov. 01, 2023
USD ($)
$ / shares
shares
Aug. 01, 2023
USD ($)
$ / shares
shares
May 01, 2023
USD ($)
$ / shares
shares
May 02, 2022
USD ($)
$ / shares
shares
Jul. 27, 2021
USD ($)
Jan. 27, 2021
USD ($)
Oct. 30, 2020
component
Sep. 30, 2023
USD ($)
$ / shares
shares
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Related Party Transaction [Line Items]                      
Service expense                 $ 19,828,000 $ 19,831,000 $ 17,316,000
Waiver of internal administrative services expenses                 8,308,000 4,540,000 4,317,000
Accounts payable and other liabilities                 255,000 1,292,000  
Related Party | MSC Income | Advisory Agreement                      
Related Party Transaction [Line Items]                      
Base fee rate             1.75%        
Number of components related to incentive fee | component             2        
Related Party | MSC Income | Advisory Agreement, Incentive Rate, Pre-Incentive Fee Net Investment Income                      
Related Party Transaction [Line Items]                      
Incentive fee rate             20.00%        
Related Party | MSC Income | Advisory Agreement - Incentive Rate, Quarterly Hurdle Rate                      
Related Party Transaction [Line Items]                      
Incentive fee rate             1.875%        
Related Party | MSC Income | Advisory Agreement - Incentive Rate, Annualized Hurdle Rate                      
Related Party Transaction [Line Items]                      
Incentive fee rate             7.50%        
Related Party | MSC Income | Advisory Agreement, Incentive Rate, Pre-Incentive Fee Net Investment Income Below Catch-Up Threshold                      
Related Party Transaction [Line Items]                      
Incentive fee rate             100.00%        
Related Party | MSC Income | Advisory Agreement - Incentive Rate, Quarterly Catch-Up Threshold                      
Related Party Transaction [Line Items]                      
Incentive fee rate             2.34375%        
Related Party | MSC Income | Advisory Agreement - Incentive Rate, Annualized Catch-Up Threshold                      
Related Party Transaction [Line Items]                      
Incentive fee rate             9.375%        
Related Party | MSC Income | Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Exceeds Catch-Up Threshold                      
Related Party Transaction [Line Items]                      
Incentive fee rate             20.00%        
Related Party | MSC Income | Advisory Agreement - Base Management Fees                      
Related Party Transaction [Line Items]                      
Service expense                 19,800,000 19,800,000 17,300,000
Related Party | MSC Income | Advisory Agreement - Subordinated Incentive Fees                      
Related Party Transaction [Line Items]                      
Service expense                 12,600,000 2,100,000 600,000
Related Party | MSC Income | Advisory Agreement - Incentive Fees, Capital Gains Fees                      
Related Party Transaction [Line Items]                      
Service expense                 0 0 0
Related Party | MSC Income | Advisory Agreement - Internal Administrative Services                      
Related Party Transaction [Line Items]                      
Service expense                 8,900,000 5,100,000 4,300,000
Waiver of internal administrative services expenses                 $ 8,300,000 4,500,000 $ 4,300,000
Related Party | MSC Income - HMS Adviser | Offering Costs                      
Related Party Transaction [Line Items]                      
Percentage of payment of offering costs                 1.50%    
Accounts payable and other liabilities                 $ 600,000    
Fee paid indirectly                 $ 100,000 $ 300,000  
Related Party | Main Street | Dividend Reinvestment Plan                      
Related Party Transaction [Line Items]                      
Sale of stock, number of shares (in shares) | shares 475,888 348,542 255,754 94,697              
Sale of stock, price per share (in dollars per share) | $ / shares $ 7.88 $ 7.89 $ 7.82 $ 7.92              
Sale of stock, proceeds $ 3,750,000 $ 2,800,000 $ 2,000,000 $ 750,000              
Related Party | Main Street | Dutch Auction Tender Offer                      
Related Party Transaction [Line Items]                      
Sale of stock, number of shares (in shares) | shares               115,385      
Sale of stock, price per share (in dollars per share) | $ / shares               $ 6.50      
Sale of stock, proceeds               $ 800,000      
Related Party | Main Street | Main Street Term Loan | Unsecured Debt                      
Related Party Transaction [Line Items]                      
Amounts of transaction         $ 60,000,000 $ 40,000,000          
Upfront fees rate           1.00%          
Amounts of transaction, increase (decrease)         $ 20,000,000            
Rate         5.00%            
Related Party | Main Street | Main Street Term Loan, Delayed | Unsecured Debt                      
Related Party Transaction [Line Items]                      
Amounts of transaction         $ 15,000,000            
Related Party | Main Street | Main Street Term Loan, Delayed | Unsecured Debt | Debt Instrument, Tranche One                      
Related Party Transaction [Line Items]                      
Amounts of transaction         7,500,000            
Related Party | Main Street | Main Street Term Loan, Delayed | Unsecured Debt | Debt Instrument, Tranche Two                      
Related Party Transaction [Line Items]                      
Amounts of transaction         $ 7,500,000