FAIR VALUE MEASUREMENTS - Measurement Inputs and Valuation Techniques (Details) $ in Thousands	Jun. 30, 2025 USD ($)		Mar. 31, 2025 USD ($)
Fair Value
Investments at fair value	$ 1,780,198	[1],[2],[3],[4],[5]	$ 1,785,299	[6],[7],[8],[9],[10]
Significant Unobservable Inputs (Level 3)
Fair Value
Investments at fair value	1,780,198		1,785,299
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Discount Rate
Fair Value
Investments at fair value	1,549,162		1,448,656
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Third Party Broker Quote
Fair Value
Investments at fair value	$ 3,400		$ 6,923
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.048		0.052
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Minimum | Third Party Broker Quote
Significant Unobservable Inputs
Significant Level 3 Inputs	0.400		0.400
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.592		0.647
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Maximum | Third Party Broker Quote
Significant Unobservable Inputs
Significant Level 3 Inputs	0.700		1.000
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.120		0.128
Significant Unobservable Inputs (Level 3) | First lien loans | Income Approach | Weighted Average | Third Party Broker Quote
Significant Unobservable Inputs
Significant Level 3 Inputs	0.609		0.798
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach
Fair Value
Investments at fair value	$ 30,172		$ 125,500
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach | Minimum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	0.980		0.898
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach | Maximum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	1.000		1.000
Significant Unobservable Inputs (Level 3) | First lien loans | Market Approach | Weighted Average | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	0.985		0.979
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach
Fair Value
Investments at fair value	$ 12,604		$ 5,543
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.151		0.210
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	7.9		3.0
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.482		0.492
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	9.0		9.0
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.151		0.210
Significant Unobservable Inputs (Level 3) | First lien loans | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	7.9		3.0
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach
Fair Value
Investments at fair value	$ 17,383
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Discount Rate
Fair Value
Investments at fair value			$ 18,066
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.088		0.095
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.624		0.412
Significant Unobservable Inputs (Level 3) | Second lien loans | Income Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.133		0.133
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach
Fair Value
Investments at fair value	$ 0		$ 0
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.213		0.210
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	3.0		3.0
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.213		0.210
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	3.0		3.0
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.000		0.000
Significant Unobservable Inputs (Level 3) | Second lien loans | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	0.0		0.0
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Discount Rate
Fair Value
Investments at fair value	$ 524		$ 538
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Third Party Broker Quote
Fair Value
Investments at fair value	$ 58		$ 58
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.145		0.144
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Minimum | Third Party Broker Quote
Significant Unobservable Inputs
Significant Level 3 Inputs	0.250		0.250
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.145		0.144
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Maximum | Third Party Broker Quote
Significant Unobservable Inputs
Significant Level 3 Inputs	0.250		0.250
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.145		0.144
Significant Unobservable Inputs (Level 3) | Subordinated debt | Income Approach | Weighted Average | Third Party Broker Quote
Significant Unobservable Inputs
Significant Level 3 Inputs	0.250		0.250
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach
Fair Value
Investments at fair value	$ 125		$ 65
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach | Minimum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	1.000		1.000
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach | Maximum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	1.000		1.000
Significant Unobservable Inputs (Level 3) | Subordinated debt | Market Approach | Weighted Average | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	1.000		1.000
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach
Fair Value
Investments at fair value	$ 557		$ 557
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.146		0.133
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	6.4		6.1
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.178		0.176
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	7.8		7.6
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.156		0.147
Significant Unobservable Inputs (Level 3) | Subordinated debt | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	6.8		6.6
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach
Fair Value
Investments at fair value			$ 2,900
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach | Minimum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs			1.000
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach | Maximum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs			1.000
Significant Unobservable Inputs (Level 3) | Preferred equity | Market Approach | Weighted Average | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs			1.000
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach
Fair Value
Investments at fair value	$ 66,230		$ 100,018
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.120		0.111
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	3.0		3.0
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.482		0.492
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	17.2		16.9
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.168		0.159
Significant Unobservable Inputs (Level 3) | Preferred equity | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	8.0		8.8
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach
Fair Value
Investments at fair value	$ 1,000		$ 1,597
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach | Minimum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	1.000		1.000
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach | Maximum | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	1.000		1.000
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Market Approach | Weighted Average | Cost
Significant Unobservable Inputs
Significant Level 3 Inputs	1.000		1.000
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach
Fair Value
Investments at fair value	$ 95,526		$ 74,878
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.127		0.119
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Minimum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	3.0		3.0
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.244		0.233
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Maximum | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	16.5		16.0
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.152		0.144
Significant Unobservable Inputs (Level 3) | Common equity & warrants | Enterprise Value Waterfall Approach | Weighted Average | EBITDA Multiple
Significant Unobservable Inputs
Significant Level 3 Inputs	8.5		8.4
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach
Fair Value
Investments at fair value	$ 3,457
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach | Minimum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.343
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach | Maximum | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.343
Significant Unobservable Inputs (Level 3) | Earnout | Income Approach | Weighted Average | Discount Rate
Significant Unobservable Inputs
Significant Level 3 Inputs	0.343

[1] All debt investments are income-producing, unless otherwise noted. Equity investments are non-income producing, unless otherwise noted. All amounts are stated in U.S. Dollars.

[2] Non-Control/Non-Affiliate investments are generally defined by the 1940 Act as investments that are neither control investments nor affiliate investments. Investments are classified as non-control/non-affiliate investments, unless otherwise noted. At June 30, 2025, the Company held $1,449.5 million of non-control/non-affiliate investments, which represented approximately 81.4% of the Company’s investment assets. The fair value of these investments as a percent of net assets is 158.1%.

[3] The Company's investment portfolio is comprised entirely of debt and equity securities of privately held companies for which quoted prices falling within the categories of Level 1 and Level 2 inputs are not readily available. Therefore, the Company values all of its portfolio investments at fair value, as determined in good faith by the valuation committee comprised of certain officers of the Company (the "Valuation Committee") as the valuation designee of the Board of Directors (the "Valuation Designee") pursuant to Rule 2a-5 under the Investment Company Act of 1940, as amended (the “1940 Act”), using significant unobservable Level 3 inputs. Refer to Note 4 - Fair Value Measurements for further discussion.

[4] Equity ownership may be held in shares or units of a company that is either wholly owned by the portfolio company or under common control by the same parent company to the portfolio company.

[5] Unless otherwise noted, all portfolio company headquarters are based in the United States.

[6] Equity ownership may be held in shares or units of a company that is either wholly owned by the portfolio company or under common control by the same parent company to the portfolio company.

[7] Unless otherwise noted, all portfolio company headquarters are based in the United States.

[8] All debt investments are income-producing, unless otherwise noted. Equity investments are non-income producing, unless otherwise noted. All amounts are stated in U.S. Dollars.

[9] Non-Control/Non-Affiliate investments are generally defined by the 1940 Act as investments that are neither control investments nor affiliate investments. Investments are classified as non-control/non-affiliate investments, unless otherwise noted. At March 31, 2025, the Company held $1,436.3 million of non-control/non-affiliate investments, which represented approximately 80.5% of the Company’s investment assets. The fair value of these investments as a percent of net assets is 162.6%.

[10] The Company's investment portfolio is comprised entirely of debt and equity securities of privately held companies for which quoted prices falling within the categories of Level 1 and Level 2 inputs are not readily available. Therefore, the Company values all of its portfolio investments at fair value, as determined in good faith by the valuation committee comprised of certain officers of the Company (the "Valuation Committee") as the valuation designee of the Board of Directors (the "Valuation Designee") pursuant to Rule 2a-5 under the Investment Company Act of 1940, as amended (the “1940 Act”), using significant unobservable Level 3 inputs. Refer to Note 4 - Fair Value Measurements for further discussion.