Annual report [Section 13 and 15(d), not S-K Item 405]

INVESTMENTS - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details)

v3.26.1
INVESTMENTS - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details)
$ in Thousands
Mar. 31, 2026
USD ($)
Mar. 31, 2025
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 1,309,248 [1] $ 979,320 [2]
Significant Unobservable Inputs (Level 3)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 1,304,243 974,345
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Secured First Lien Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 570,602 514,334
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Secured Second Lien Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 99,197 90,956
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Preferred Equity    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 426,949 302,163
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Common Equity/ Equivalents    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 207,495 $ 54,268
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Secured First Lien Debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 3.6 3.7
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Secured First Lien Debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 8.7 7.9
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Secured First Lien Debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 6.4 6.0
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Secured Second Lien Debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 5.0 6.1
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Secured Second Lien Debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 10.3 7.2
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Secured Second Lien Debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 7.6 6.8
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Preferred Equity | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 3.6 3.7
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Preferred Equity | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 8.7 7.9
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Preferred Equity | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 6.4 6.1
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Common Equity/ Equivalents | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 5.0 5.5
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Common Equity/ Equivalents | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 10.3 7.2
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA multiple | Common Equity/ Equivalents | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 9.0 6.8
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Secured First Lien Debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 430 $ 1,208
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Secured First Lien Debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 28,973 25,038
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Secured First Lien Debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 11,991 12,162
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Secured Second Lien Debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 3,000 3,637
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Secured Second Lien Debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 44,315 24,234
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Secured Second Lien Debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 19,510 16,900
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Preferred Equity | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 430 2,153
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Preferred Equity | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 28,973 25,038
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Preferred Equity | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 9,870 11,029
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Common Equity/ Equivalents | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 1,210 1,208
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Common Equity/ Equivalents | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 44,315 24,234
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | EBITDA | Common Equity/ Equivalents | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 32,353 $ 18,562
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue multiple | Secured First Lien Debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 0.3 0.3
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue multiple | Secured First Lien Debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 0.6 0.6
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue multiple | Secured First Lien Debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 0.5 0.4
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue multiple | Preferred Equity | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 0.3 0.3
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue multiple | Preferred Equity | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 0.6 0.6
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue multiple | Preferred Equity | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input 0.4 0.4
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue | Secured First Lien Debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 21,768 $ 6,690
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue | Secured First Lien Debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 99,974 102,791
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue | Secured First Lien Debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 62,789 72,303
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue | Preferred Equity | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 21,768 6,690
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue | Preferred Equity | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 99,974 102,791
Significant Unobservable Inputs (Level 3) | Total Enterprise Value | Revenue | Preferred Equity | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value 76,364 53,604
Significant Unobservable Inputs (Level 3) | Yield Analysis | Secured Second Lien Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 0 $ 12,624
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured Second Lien Debt | Minimum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input   0.207
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured Second Lien Debt | Maximum    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input   0.207
Significant Unobservable Inputs (Level 3) | Yield Analysis | Discount Rate | Secured Second Lien Debt | Weighted Average    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair value, measurement input   0.207
[1] Cumulative gross unrealized appreciation for federal income tax purposes is $428.5 million; cumulative gross unrealized depreciation for federal income tax purposes is $173.7 million. Cumulative net unrealized appreciation is $254.8 million, based on a tax cost of $1.1 billion.
[2] Cumulative gross unrealized appreciation for federal income tax purposes is $183.3 million; cumulative gross unrealized depreciation for federal income tax purposes is $144.9 million. Cumulative net unrealized appreciation is $38.5 million, based on a tax cost of $940.9 million.