Annual report pursuant to Section 13 and 15(d)


Cover - USD ($)
12 Months Ended
Dec. 31, 2022
Mar. 09, 2023
Jun. 30, 2022
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2022    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Securities Act File Number 814-00939    
Entity Registrant Name MSC Income Fund, Inc.    
Entity Incorporation, State or Country Code MD    
Entity Tax Identification Number 45-3999996    
Entity Address, Address Line One 1300 Post Oak Boulevard    
Entity Address, Address Line Two 8th Floor    
Entity Address, City or Town Houston    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 77056    
City Area Code 713    
Local Phone Number 350-6000    
Title of 12(g) Security Common Stock, par value $0.001 per share    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Entity Shell Company false    
Entity Public Float     $ 0
Entity Common Stock, Shares Outstanding   80,151,040  
Documents Incorporated by Reference None.    
Document Fiscal Year Focus 2022    
Entity Central Index Key 0001535778    
Amendment Flag false    
Document Fiscal Period Focus FY