Quarterly report pursuant to Section 13 or 15(d)

INVESTMENTS - Investment Holdings (Details)

v3.24.0.1
INVESTMENTS - Investment Holdings (Details) - USD ($)
$ in Thousands
 9 Months Ended 12 Months Ended
Dec. 31, 2023
Mar. 31, 2023
Summary of Investment Holdings [Line Items]    
Cost $ 868,504 $ 720,630 [1]
Fair Value 902,808 753,543 [1]
South    
Summary of Investment Holdings [Line Items]    
Fair Value 326,849 171,056
West    
Summary of Investment Holdings [Line Items]    
Fair Value 228,407 197,989
Northeast    
Summary of Investment Holdings [Line Items]    
Fair Value 213,403 266,612
Midwest    
Summary of Investment Holdings [Line Items]    
Fair Value 134,149 117,886
Diversified/Conglomerate Services    
Summary of Investment Holdings [Line Items]    
Fair Value 255,141 268,954
Home and Office Furnishings, Housewares, and Durable Consumer Products    
Summary of Investment Holdings [Line Items]    
Fair Value 155,897 143,685
Machinery (Non-Agriculture, Non-Construction, and Non-Electronic)    
Summary of Investment Holdings [Line Items]    
Fair Value 92,293 20,088
Hotels, Motels, Inns, and Gaming    
Summary of Investment Holdings [Line Items]    
Fair Value 80,557 58,713
Buildings and Real Estate    
Summary of Investment Holdings [Line Items]    
Fair Value 64,352 60,571
Healthcare, Education, and Childcare    
Summary of Investment Holdings [Line Items]    
Fair Value 50,237 37,445
Oil and Gas    
Summary of Investment Holdings [Line Items]    
Fair Value 45,983 0
Leisure, Amusement, Motion Pictures, and Entertainment    
Summary of Investment Holdings [Line Items]    
Fair Value 38,356 47,616
Mining, Steel, Iron and Non-Precious Metals    
Summary of Investment Holdings [Line Items]    
Fair Value 27,831 25,998
Aerospace and Defense    
Summary of Investment Holdings [Line Items]    
Fair Value 25,754 22,215
Chemicals, Plastics, and Rubber    
Summary of Investment Holdings [Line Items]    
Fair Value 19,256 24,891
Printing and Publishing    
Summary of Investment Holdings [Line Items]    
Fair Value 15,210 0
Cargo Transport    
Summary of Investment Holdings [Line Items]    
Fair Value 13,500 14,707
Telecommunications    
Summary of Investment Holdings [Line Items]    
Fair Value 8,881 18,987
Other    
Summary of Investment Holdings [Line Items]    
Fair Value $ 9,560 $ 9,673
Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Investment Owned, At Fair Value | Industry Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Diversified/Conglomerate Services    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 28.30% 35.70%
Investment Owned, At Fair Value | Industry Concentration Risk | Home and Office Furnishings, Housewares, and Durable Consumer Products    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 17.30% 19.10%
Investment Owned, At Fair Value | Industry Concentration Risk | Machinery (Non-Agriculture, Non-Construction, and Non-Electronic)    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 10.20% 2.70%
Investment Owned, At Fair Value | Industry Concentration Risk | Hotels, Motels, Inns, and Gaming    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 8.90% 7.80%
Investment Owned, At Fair Value | Industry Concentration Risk | Buildings and Real Estate    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 7.10% 8.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Healthcare, Education, and Childcare    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 5.60% 5.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Oil and Gas    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 5.10% 0.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Leisure, Amusement, Motion Pictures, and Entertainment    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 4.20% 6.30%
Investment Owned, At Fair Value | Industry Concentration Risk | Mining, Steel, Iron and Non-Precious Metals    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 3.10% 3.50%
Investment Owned, At Fair Value | Industry Concentration Risk | Aerospace and Defense    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 2.90% 2.80%
Investment Owned, At Fair Value | Industry Concentration Risk | Chemicals, Plastics, and Rubber    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 2.10% 3.30%
Investment Owned, At Fair Value | Industry Concentration Risk | Printing and Publishing    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 1.70% 0.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Cargo Transport    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 1.50% 2.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Telecommunications    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 1.00% 2.50%
Investment Owned, At Fair Value | Industry Concentration Risk | Other    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 1.00% 1.30%
Investment Owned, At Fair Value | Geographic Regions Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Investment Owned, At Fair Value | Geographic Regions Risk | South    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 36.20% 22.70%
Investment Owned, At Fair Value | Geographic Regions Risk | West    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 25.30% 26.30%
Investment Owned, At Fair Value | Geographic Regions Risk | Northeast    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 23.60% 35.40%
Investment Owned, At Fair Value | Geographic Regions Risk | Midwest    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 14.90% 15.60%
Debt Securities    
Summary of Investment Holdings [Line Items]    
Cost $ 665,697 $ 555,597
Fair Value $ 613,606 $ 513,251
Debt Securities | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 76.60% 77.10%
Debt Securities | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 67.90% 68.20%
Secured First Lien Debt    
Summary of Investment Holdings [Line Items]    
Cost $ 517,539 $ 471,439
Fair Value $ 476,126 $ 437,517
Secured First Lien Debt | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 59.60% 65.40%
Secured First Lien Debt | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 52.70% 58.10%
Secured Second Lien Debt    
Summary of Investment Holdings [Line Items]    
Cost $ 148,158 $ 84,158
Fair Value $ 137,480 $ 75,734
Secured Second Lien Debt | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 17.00% 11.70%
Secured Second Lien Debt | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 15.20% 10.10%
Equity Securities    
Summary of Investment Holdings [Line Items]    
Cost $ 202,807 $ 165,033
Fair Value $ 289,202 $ 240,292
Equity Securities | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 23.40% 22.90%
Equity Securities | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 32.10% 31.80%
Preferred Equity    
Summary of Investment Holdings [Line Items]    
Cost $ 151,969 $ 149,099
Fair Value $ 214,664 $ 222,585
Preferred Equity | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 17.50% 20.70%
Preferred Equity | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 23.80% 29.50%
Common Equity/ Equivalents    
Summary of Investment Holdings [Line Items]    
Cost $ 50,838 $ 15,934
Fair Value $ 74,538 $ 17,707
Common Equity/ Equivalents | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 5.90% 2.20%
Common Equity/ Equivalents | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 8.30% 2.30%
[1] Cumulative gross unrealized appreciation for federal income tax purposes is $150.4 million; cumulative gross unrealized depreciation for federal income tax purposes is $119.3 million. Cumulative net unrealized appreciation is $31.1 million, based on a tax cost of $722.4 million.