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CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS (Parentheticals) - $ / shares	12 Months Ended
	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	Mar. 31, 2016
Statement of Stockholders' Equity [Abstract]
Net investment income (loss) (in USD per share)	$ 0.64	$ 1.08	$ 0.92	$ 0.91	$ 0.83	$ 0.75	$ 0.69	$ 0.84	$ 0.75	$ 0.64
Gain (loss) on investment (in USD per share)	$ 1.02	$ 1.12	$ 0.49	$ 0.26	$ 0.10	$ 0.28	$ 0.24	$ 0.05	$ 0	$ 0.11

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