v3.26.1
SUBSEQUENT EVENTS (Details)
$ / shares in Units, $ in Millions
3 Months Ended 6 Months Ended 231 Months Ended
Aug. 07, 2026
USD ($)
plan
$ / shares
Dec. 31, 2026
$ / shares
Sep. 30, 2026
$ / shares
Jun. 30, 2026
$ / shares
Dec. 31, 2025
Jun. 30, 2025
$ / shares
Jun. 30, 2026
$ / shares
Jun. 30, 2025
$ / shares
Dec. 31, 2026
$ / shares
Subsequent Event [Line Items]                  
Increase in common stock, dividends, per share, declared, monthly (as a percent)         3.90%        
Dividends paid, per share (in dollars per share)       $ 1.08   $ 1.05 $ 2.16 $ 2.10  
Subsequent Event | MSC Income                  
Subsequent Event [Line Items]                  
Share purchase program, authorized, amount | $ $ 20.0                
Share repurchase program, authorized, amount | $ $ 20.0                
Share purchase (repurchase) program, number of active plans | plan 2                
O 2026 Q3 Supplemental Dividends | Subsequent Event                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share) $ 0.30                
O 2026 M4 Dividends | Subsequent Event                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share) 0.265                
O 2026 M5 Dividends | Subsequent Event                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share) 0.265                
O 2026 M6 Dividends | Subsequent Event                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share) 0.265                
O 2026 Q3 Dividends | Forecast                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share)     $ 0.795            
O 2026 Q3 Including Supplemental Dividends | Forecast                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share)     $ 1.095            
O 2026 M7 Dividends | Subsequent Event                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share) 0.265                
O 2026 M8 Dividends | Subsequent Event                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share) 0.265                
O 2026 M9 Dividends | Subsequent Event                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share) $ 0.265                
O 2026 Q4 Dividends | Forecast                  
Subsequent Event [Line Items]                  
Common stock, dividend, per share, declared (in dollars per share)   $ 0.795              
O 2026 A4 Life-To-Date Dividends | Forecast                  
Subsequent Event [Line Items]                  
Dividends paid, per share (in dollars per share)                 $ 51.205