Annual report pursuant to Section 13 and 15(d)

BORROWINGS - Revolving Line of Credit Narrative (Details)

v3.23.1
BORROWINGS - Revolving Line of Credit Narrative (Details) - USD ($)
 12 Months Ended
Mar. 08, 2021
Aug. 10, 2020
Mar. 31, 2023
Mar. 31, 2022
Aug. 09, 2020
Debt Instrument [Line Items]          
Indebtedness asset coverage on our senior securities     244.70% 252.90%  
Credit Facility          
Debt Instrument [Line Items]          
Debt instrument, term 2 years        
Credit Facility | Line of Credit          
Debt Instrument [Line Items]          
Unused fee percentage     1.00% 1.00%  
Credit Facility | Line of Credit | Revolving Line of Credit          
Debt Instrument [Line Items]          
Line of credit facility, maximum borrowing capacity   $ 180,000,000 $ 180,000,000 $ 180,000,000 $ 200,000,000
Accordion feature, increase limit   $ 300,000,000      
Covenant, required minimum net worth of mandatory redeemable term preferred stock     $ 210,000,000.0    
Covenant, required minimum net worth of mandatory redeemable term preferred stock, plus percent of all equity and subordinated debt raised     50.00%    
Covenant, required minimum net worth of mandatory redeemable term preferred stock, minus percent of any equity or subordinated debt redeemed or retired     50.00%    
Covenant, required minimum net worth of mandatory redeemable term preferred stock, plus percent of all equity and subordinated debt raised, minus percent of any equity or subordinated debt redeemed or retired     $ 289,000,000.0    
Indebtedness asset coverage on our senior securities     244.70%    
Senior security, indebtedness, asset coverage amount     $ 696,700,000    
Credit Facility | Line of Credit | Revolving Line of Credit | Minimum          
Debt Instrument [Line Items]          
Indebtedness asset coverage on our senior securities     150.00%    
Credit Facility | Line of Credit | Revolving Line of Credit | Less than or Equal to 50% of Commitment          
Debt Instrument [Line Items]          
Unused fee percentage   0.50%      
Credit Facility | Line of Credit | Revolving Line of Credit | Greater than 50% but Less than or Equal to 65% of Commitment          
Debt Instrument [Line Items]          
Unused fee percentage   0.75%      
Credit Facility | Line of Credit | Revolving Line of Credit | Greater Than 65% Of Commitment          
Debt Instrument [Line Items]          
Unused fee percentage   1.00%      
Credit Facility | LIBOR | Line of Credit | Revolving Line of Credit          
Debt Instrument [Line Items]          
Debt instrument, variable rate floor   0.50% 0.50% 0.50%  
Debt instrument, basis spread on variable rate     2.94% 2.85%  
Credit Facility | LIBOR, Tranche One | Line of Credit | Revolving Line of Credit          
Debt Instrument [Line Items]          
Debt instrument, basis spread on variable rate   2.85%      
Credit Facility | LIBOR, Tranche Two | Line of Credit | Revolving Line of Credit          
Debt Instrument [Line Items]          
Debt instrument, basis spread on variable rate   3.10%      
Credit Facility | LIBOR, Thereafter | Line of Credit | Revolving Line of Credit          
Debt Instrument [Line Items]          
Debt instrument, basis spread on variable rate   3.35%