Investments - Summary of PSLF's Portfolio at Fair Value (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2025 USD ($) Portfolio		Sep. 30, 2024 USD ($) Portfolio
Schedule Of Investments [Line Items]
Investments at fair value (amortized cost - $1,289,319 and $1,036,305 respectively)	$ 1,287,273	[1],[2]	$ 1,328,050	[3],[4],[5]
PSLF
Schedule Of Investments [Line Items]
Investments at fair value (amortized cost - $1,289,319 and $1,036,305 respectively)	$ 1,265,901		$ 1,031,225	[6],[7],[8]
Weighted average cost yield on income producing investments	10.10%		11.30%
Number of portfolio companies in PSLF | Portfolio	109		102
Largest portfolio company investment at fair value	$ 24,802		$ 25,073
Total of five largest portfolio company investments at fair value	$ 121,360		$ 109,927

[1] All investments are in US Companies unless noted otherwise. Total cost, fair value, and percentage of Net Assets for the U.S. Companies were $1,181.8 million, $1,198.6 million, and 258.4%

[2] Valued based on our accounting policy (See Note 2).

[3] The provisions of the 1940 Act classify investments based on the level of control that we maintain in a particular portfolio company. As defined in the 1940 Act, a company is generally presumed to be “non-controlled” when we own 25% or less of the portfolio company’s voting securities and “controlled” when we own more than 25% of the portfolio company’s voting securities.

[4] The provisions of the 1940 Act classify investments further based on the level of ownership that we maintain in a particular portfolio company. As defined in the 1940 Act, a company is generally deemed as “non-affiliated” when we own less than 5% of a portfolio company’s voting securities and “affiliated” when we own 5% or more of a portfolio company’s voting securities (See Note 6).

[5] Valued based on our accounting policy (See Note 2).

[6] All of our investments are not registered under the 1933 Act and have restrictions on resale.

[7] As of September 30, 2024, all investments are in US Companies. Total cost, fair value, and percentage of Net Assets for U.S. Companies were $1,036.3 million, $1,031.2 million and 918.5%

[8] Valued based on PSLF’s accounting policy.