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

FINANCIAL HIGHLIGHTS (Details)

v3.26.1
FINANCIAL HIGHLIGHTS (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Mar. 31, 2022
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2017
Investment Company, Financial Highlights [Roll Forward]                    
Net asset value at beginning of period (in USD per share) $ 13.55 $ 13.43 $ 13.09 $ 13.43 $ 11.52 $ 11.17 $ 12.40 $ 10.85 $ 9.95 $ 9.22
(Loss) income from investment operations                    
Net investment (loss) income, basic (in USD per share) (0.10) 0.76 0.63 1.11 0.45 0.54 1.11 0.23 0.68 0.74
Net realized (loss) gain on investments and other (in USD per share) (0.71) 1.72 0.88 0.32 0.37 0.32 1.36 2.04 0.04 0.51
Taxes on deemed distributions of long-term capital gains (in USD per share) 0 0 0 0 0 0 (0.31) (0.41) 0 0
Net unrealized appreciation (depreciation) of investments and other (in USD per share) 5.58 (0.70) 0.96 (0.36) 2.26 0.42 (2.38) 0.63 1.16 0.23
Total from investment operations (in USD per share) 4.77 1.78 2.47 1.07 3.08 1.28 (0.22) 2.49 1.88 1.48
Effect of equity capital activity                    
Cash distributions to common stockholders from net investment income (in USD per share) (0.99) (0.64) (1.08) (0.92) (0.91) (0.83) (0.75) (0.69) (0.84) (0.75)
Cash distributions to common stockholders from net realized gains (in USD per share) (0.51) (1.02) (1.12) (0.49) (0.26) (0.10) (0.28) (0.24) (0.05) 0
Discounts, commissions, and offering costs par share (in USD per share) (0.02) 0 (0.02) (0.01) 0 0 0 0 (0.03) 0
Net accretive (dilutive) effect of equity offering (in USD per share) 0.07 0 0.10 0.01 0 0 0.01 0 (0.04) 0
Total from equity capital activity (in USD per share) (1.45) (1.66) (2.12) (1.41) (1.17) (0.93) (1.02) (0.93) (0.96) (0.75)
Other, net (in USD per share) (0.09) 0 (0.01) 0 0 0 0.01 (0.01) (0.02) 0
Net asset value at end of period (in USD per share) 16.78 13.55 13.43 13.09 13.43 11.52 11.17 12.40 10.85 9.95
Per common share market value at beginning of period (in USD per share) 13.36 14.23 13.25 16.13 12.23 7.85 11.60 10.10 9.07 7.02
Per common share market value at end of period (in USD per share) $ 14.20 $ 13.36 $ 14.23 $ 13.25 $ 16.13 $ 12.23 $ 7.85 $ 11.60 $ 10.10 $ 9.07
Total investment return 18.14% 5.65% 25.52% (8.90%) 42.40% 70.65% (26.23%) 24.95% 21.82% 41.58%
Common stock outstanding at end of period (in shares) 39,821,967 36,837,381 36,688,667 33,591,505 33,205,023 33,205,023 33,049,463 32,822,459 32,653,635 30,270,958
Weighted-average shares of common stock outstanding - basic (in shares) 38,712,611 36,735,218 34,466,724 33,311,785 33,205,023 33,176,760 32,865,840 32,807,597 32,268,776 30,270,958
Weighted-average shares of common stock outstanding - diluted (in shares) 38,712,611 36,735,218 34,466,724 33,311,785 33,205,023 33,176,760 32,865,840 32,807,597 32,268,776 30,270,958
Consolidated Statement of Assets and Liabilities Data:                    
Net assets at end of year $ 668,225 $ 499,084 $ 492,711 $ 439,742 $ 445,830 $ 382,364 $ 369,031 $ 407,110 $ 354,200 $ 301,082
Average net assets 545,378 478,440 461,819 446,899 425,985 365,568 404,336 391,786 328,533 294,030
Senior Securities Data:                    
Total borrowings, at cost 572,888 463,738 404,238 297,688 267,584 155,434 54,296 58,096 112,096 74,796
Mandatorily redeemable preferred stock $ 0 $ 0 $ 0 $ 0 $ 0 $ 94,371 $ 132,250 $ 132,250 $ 139,150 $ 139,150
Ratios/Supplemental Data:                    
Ratio of net expenses to average net assets 18.85% 13.70% 14.19% 9.97% 13.51% 10.58% 6.32% 13.30% 11.08% 10.02%
Ratio of net investment (loss) income to average net assets (0.69%) 5.87% 4.72% 8.28% 3.52% 4.91% 8.99% 1.92% 6.68% 7.63%
Portfolio turnover ratio 1.68% 20.41% 9.58% 12.45% 12.34% 8.99% 21.27% 17.16% 14.87% 13.86%
Ratio of expenses to average net assets - annualized 22.02% 16.79% 17.38% 12.58% 16.72% 13.33% 9.12% 16.45% 14.11% 13.46%
Ratio of net expenses to average net assets             6.89% 14.07%    
Ratio of net investment (loss) income to average net assets – annualized (3.85%) 2.79% 1.53% 5.66% 0.31% 2.16% 6.20% (1.22%) 3.66% 4.19%