v3.23.3
Commitments and Contingencies - Schedule of Unfunded Commitments by Investment (Details) - USD ($)
$ in Thousands
Sep. 30, 2023
Sep. 30, 2022
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments $ 232,740 $ 224,239
Investment, Identifier [Axis]: 107 Fair Street LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 4,227 0
Investment, Identifier [Axis]: 107-109 Beech OAK22 LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 26,969 0
Investment, Identifier [Axis]: 109 Montgomery Owner LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 477
Investment, Identifier [Axis]: 112-126 Van Houten Real22 LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,343 0
Investment, Identifier [Axis]: ADC Therapeutics SA    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 3,020 3,020
Investment, Identifier [Axis]: ASP-R-PAC Acquisition Co LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 396 0
Investment, Identifier [Axis]: Accupac, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 4,500 4,605
Investment, Identifier [Axis]: Acquia Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,376 1,326
Investment, Identifier [Axis]: Apptio, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 1,338
Investment, Identifier [Axis]: Ardonagh Midco 3 PLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 4,372
Investment, Identifier [Axis]: Assembled Brands Capital LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 7,514 2,008
Investment, Identifier [Axis]: Avalara, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 5,047 0
Investment, Identifier [Axis]: BAART Programs, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 8,645
Investment, Identifier [Axis]: Berner Food & Beverage, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,622 1,392
Investment, Identifier [Axis]: BioXcel Therapeutics, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 14,547 11,785
Investment, Identifier [Axis]: CorEvitas, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 915
Investment, Identifier [Axis]: Coupa Holdings, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,075 0
Investment, Identifier [Axis]: Coyote Buyer, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 400 1,333
Investment, Identifier [Axis]: Delta Leasing SPV II LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 14,639 27,187
Investment, Identifier [Axis]: Dialyze Holdings, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 3,431
Investment, Identifier [Axis]: Digital.AI Software Holdings, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,078 826
Investment, Identifier [Axis]: Dominion Diagnostics, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 3,484 11,148
Investment, Identifier [Axis]: Establishment Labs Holdings Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 3,384 5,075
Investment, Identifier [Axis]: Evergreen IX Borrower 2023, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,626 0
Investment, Identifier [Axis]: Fairbridge Strategic Capital Funding LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 13,090 22,150
Investment, Identifier [Axis]: Finastra USA, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 960 0
Investment, Identifier [Axis]: GKD Index Partners, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 320
Investment, Identifier [Axis]: Galileo Parent, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,061 0
Investment, Identifier [Axis]: Grove Hotel Parcel Owner, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 5,286 4,293
Investment, Identifier [Axis]: Harrow, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 4,011 0
Investment, Identifier [Axis]: Impel Pharmaceuticals Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,458 0
Investment, Identifier [Axis]: Innocoll Pharmaceuticals Limited    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 4,195
Investment, Identifier [Axis]: Inventus Power, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 3,792 0
Investment, Identifier [Axis]: Kings Buyer, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 5,189 1,537
Investment, Identifier [Axis]: LSL Holdco, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,650 427
Investment, Identifier [Axis]: Liquid Environmental Solutions Corporation    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,383 1,115
Investment, Identifier [Axis]: MHE Intermediate Holdings, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 821 1,429
Investment, Identifier [Axis]: MND Holdings III Corp    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 9,122 0
Investment, Identifier [Axis]: MRI Software LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,261 5,196
Investment, Identifier [Axis]: Marinus Pharmaceuticals, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 5,734
Investment, Identifier [Axis]: Mesoblast, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 3,553
Investment, Identifier [Axis]: Mindbody, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 4,762 4,000
Investment, Identifier [Axis]: OCSI Glick JV LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 13,998 13,998
Investment, Identifier [Axis]: OTG Management, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 3,190 3,789
Investment, Identifier [Axis]: Oranje Holdco, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,904 0
Investment, Identifier [Axis]: PPW Aero Buyer, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,466 0
Investment, Identifier [Axis]: PRGX Global, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 3,127 2,518
Investment, Identifier [Axis]: Pluralsight, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,787 3,532
Investment, Identifier [Axis]: Relativity ODA LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,762 2,218
Investment, Identifier [Axis]: RumbleOn, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 4,822
Investment, Identifier [Axis]: SCP Eye Care Services, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,356 0
Investment, Identifier [Axis]: SIO2 Medical Products, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 1,821 0
Investment, Identifier [Axis]: Salus Workers' Compensation, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 3,102 0
Investment, Identifier [Axis]: Senior Loan Fund JV I, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 13,125 35,000
Investment, Identifier [Axis]: Seres Therapeutics, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 8,090 0
Investment, Identifier [Axis]: Spanx, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,473 2,226
Investment, Identifier [Axis]: Supreme Fitness Group NY Holdings, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,199 1,527
Investment, Identifier [Axis]: Tahoe Bidco B.V.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 2,162 1,741
Investment, Identifier [Axis]: Telestream Holdings Corporation    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 407 528
Investment, Identifier [Axis]: Thrasio, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 0 2,578
Investment, Identifier [Axis]: iCIMs, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments 7,466 6,930
Investment, Identifier [Axis]: scPharmaceuticals Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded commitments $ 5,212 $ 0