Quarterly report pursuant to Section 13 or 15(d)

INVESTMENTS - Summary Investment Holdings (Details)

v3.23.2
INVESTMENTS - Summary Investment Holdings (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Jun. 30, 2023
Mar. 31, 2023
Summary of Investment Holdings [Line Items]    
Cost $ 767,985 $ 720,630 [1]
Fair Value 800,078 753,543 [1]
Northeast    
Summary of Investment Holdings [Line Items]    
Fair Value 258,179 266,612
West    
Summary of Investment Holdings [Line Items]    
Fair Value 215,362 197,989
South    
Summary of Investment Holdings [Line Items]    
Fair Value 200,067 171,056
Midwest    
Summary of Investment Holdings [Line Items]    
Fair Value 126,470 117,886
Diversified/Conglomerate Services    
Summary of Investment Holdings [Line Items]    
Fair Value 296,479 268,954
Home and Office Furnishings, Housewares, and Durable Consumer Products    
Summary of Investment Holdings [Line Items]    
Fair Value 147,007 143,685
Hotels, Motels, Inns, and Gaming    
Summary of Investment Holdings [Line Items]    
Fair Value 61,185 58,713
Buildings and Real Estate    
Summary of Investment Holdings [Line Items]    
Fair Value 59,822 60,571
Leisure, Amusement, Motion Pictures, and Entertainment    
Summary of Investment Holdings [Line Items]    
Fair Value 39,948 47,616
Healthcare, Education, and Childcare    
Summary of Investment Holdings [Line Items]    
Fair Value 38,465 37,445
Mining, Steel, Iron and Non-Precious Metals    
Summary of Investment Holdings [Line Items]    
Fair Value 26,277 25,998
Aerospace and Defense    
Summary of Investment Holdings [Line Items]    
Fair Value 25,696 22,215
Chemicals, Plastics, and Rubber    
Summary of Investment Holdings [Line Items]    
Fair Value 25,454 24,891
Machinery (Non-Agriculture, Non-Construction, and Non-Electronic)    
Summary of Investment Holdings [Line Items]    
Fair Value 23,075 20,088
Telecommunications    
Summary of Investment Holdings [Line Items]    
Fair Value 16,800 18,987
Printing and Publishing    
Summary of Investment Holdings [Line Items]    
Fair Value 15,275 0
Cargo Transport    
Summary of Investment Holdings [Line Items]    
Fair Value 14,487 14,707
Diversified/Conglomerate Manufacturing    
Summary of Investment Holdings [Line Items]    
Fair Value 10,077 9,646
Other    
Summary of Investment Holdings [Line Items]    
Fair Value $ 31 $ 27
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 37.10% 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 18.40% 19.10%
Investment Owned, At Fair Value | Industry Concentration Risk | Hotels, Motels, Inns, and Gaming    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 7.60% 7.80%
Investment Owned, At Fair Value | Industry Concentration Risk | Buildings and Real Estate    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 7.50% 8.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Leisure, Amusement, Motion Pictures, and Entertainment    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 5.00% 6.30%
Investment Owned, At Fair Value | Industry Concentration Risk | Healthcare, Education, and Childcare    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 4.80% 5.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Mining, Steel, Iron and Non-Precious Metals    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 3.30% 3.50%
Investment Owned, At Fair Value | Industry Concentration Risk | Aerospace and Defense    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 3.20% 2.80%
Investment Owned, At Fair Value | Industry Concentration Risk | Chemicals, Plastics, and Rubber    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 3.10% 3.30%
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 2.90% 2.70%
Investment Owned, At Fair Value | Industry Concentration Risk | Telecommunications    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 2.10% 2.50%
Investment Owned, At Fair Value | Industry Concentration Risk | Printing and Publishing    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 1.90% 0.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Cargo Transport    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 1.80% 2.00%
Investment Owned, At Fair Value | Industry Concentration Risk | Diversified/Conglomerate Manufacturing    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 1.30% 1.30%
Investment Owned, At Fair Value | Industry Concentration Risk | Other    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 0.00% 0.00%
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 | Northeast    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 32.30% 35.40%
Investment Owned, At Fair Value | Geographic Regions Risk | West    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 26.90% 26.30%
Investment Owned, At Fair Value | Geographic Regions Risk | South    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 25.00% 22.70%
Investment Owned, At Fair Value | Geographic Regions Risk | Midwest    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 15.80% 15.60%
Debt Securities    
Summary of Investment Holdings [Line Items]    
Cost $ 595,297 $ 555,597
Fair Value $ 557,009 $ 513,251
Debt Securities | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 77.50% 77.10%
Debt Securities | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 69.60% 68.20%
Secured First Lien Debt    
Summary of Investment Holdings [Line Items]    
Cost $ 486,139 $ 471,439
Fair Value $ 452,215 $ 437,517
Secured First Lien Debt | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 63.30% 65.40%
Secured First Lien Debt | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 56.50% 58.10%
Secured Second Lien Debt    
Summary of Investment Holdings [Line Items]    
Cost $ 109,158 $ 84,158
Fair Value $ 104,794 $ 75,734
Secured Second Lien Debt | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 14.20% 11.70%
Secured Second Lien Debt | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 13.10% 10.10%
Equity Securities    
Summary of Investment Holdings [Line Items]    
Cost $ 172,688 $ 165,033
Fair Value $ 243,069 $ 240,292
Equity Securities | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 22.50% 22.90%
Equity Securities | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 30.40% 31.80%
Preferred Equity    
Summary of Investment Holdings [Line Items]    
Cost $ 152,374 $ 149,099
Fair Value $ 214,258 $ 222,585
Preferred Equity | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 19.80% 20.70%
Preferred Equity | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 26.80% 29.50%
Common Equity/ Equivalents    
Summary of Investment Holdings [Line Items]    
Cost $ 20,314 $ 15,934
Fair Value $ 28,811 $ 17,707
Common Equity/ Equivalents | Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 2.70% 2.20%
Common Equity/ Equivalents | Investment Owned, At Fair Value | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 3.60% 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.