Fair Value of Financial Instruments - Summary of Unobservable Inputs and Ranges (Details) - Level 3
$ in Thousands

Mar. 31, 2026

USD ($)

Sep. 30, 2025

USD ($)

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 934,607

$ 1,087,964

Truist Credit Facility | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 199,480

$ 425,477

Range of Input

^[1]

0.056

0.049

Equity | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 231,006

$ 286,210

Minimum | Equity | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.009

0.015

Maximum | Equity | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.28

0.283

Weighted Average | Equity | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.11

0.094

First Lien | Market Comparable | Broker/Dealer Bids or Quotes

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 27,210

$ 31,018

First Lien | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

424,229

550,259

First Lien | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 30,261

$ 1,096

First Lien | Minimum | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.07

0.04

First Lien | Minimum | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[2]

0.009

0.075

First Lien | Maximum | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.201

0.245

First Lien | Maximum | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[2]

0.117

0.083

First Lien | Weighted Average | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.102

0.101

First Lien | Weighted Average | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[2]

0.085

0.081

Second Lien | Market Comparable | Broker/Dealer Bids or Quotes

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 3,411

Second Lien | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 14,825

$ 14,750

Second Lien | Minimum | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.132

0.132

Second Lien | Maximum | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.154

0.155

Second Lien | Weighted Average | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.142

0.143

Subordinated Debt / Corporate Notes | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 182,335

$ 201,220

Subordinated Debt / Corporate Notes | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Fair value

$ 24,741

Subordinated Debt / Corporate Notes | Minimum | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.117

0.07

Subordinated Debt / Corporate Notes | Minimum | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.009

Subordinated Debt / Corporate Notes | Maximum | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.161

0.254

Subordinated Debt / Corporate Notes | Maximum | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.262

Subordinated Debt / Corporate Notes | Weighted Average | Market Comparable | Market Yield

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.125

0.132

Subordinated Debt / Corporate Notes | Weighted Average | Enterprise Market Value | EBITDA Multiple

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]

Range of Input

^[1]

0.052

[1]	The weighted averages disclosed in the table above were weighted by their relative fair value.
[2]	The weighted averages disclosed in the table above were weighted by their relative fair value.