v3.25.2
Commitments and Contingencies - Schedule of Unfunded Commitments by Investment (Details) - USD ($)
$ in Thousands
Jun. 30, 2025
Sep. 30, 2024
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment $ 1,000,470 $ 642,044
Investment, Identifier [Axis]: 107 Fair Street LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 2,849
Investment, Identifier [Axis]: 107-109 Beech OAK22 LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 8,544 7,501
Investment, Identifier [Axis]: 112-126 Van Houten Real22 LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 870
Investment, Identifier [Axis]: ACESO Holding 4 S.A.R.L.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 9,511
Investment, Identifier [Axis]: ACP Falcon Buyer Inc    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 5,333 5,333
Investment, Identifier [Axis]: ASP Integrity Acquisition Co LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 16,554 0
Investment, Identifier [Axis]: ASP-R-PAC Acquisition Co LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 253 247
Investment, Identifier [Axis]: AVSC Holding Corp.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 12,016 0
Investment, Identifier [Axis]: Accession Risk Management Group, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 16,505 28,981
Investment, Identifier [Axis]: AmSpec Parent LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 19,666
Investment, Identifier [Axis]: Avalara, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 1,903
Investment, Identifier [Axis]: Bamboo US Bidco LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 11,395 7,220
Investment, Identifier [Axis]: BioXcel Therapeutics, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,577 4,471
Investment, Identifier [Axis]: Biscuit Parent, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 31,516 15,000
Investment, Identifier [Axis]: Blue Bidco Ltd    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 5,621 0
Investment, Identifier [Axis]: CVAUSA Management, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 13,657
Investment, Identifier [Axis]: Centralsquare Technologies, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,302 3,378
Investment, Identifier [Axis]: Cielo Bidco Limited    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 69,432 0
Investment, Identifier [Axis]: Coupa Holdings, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 2,122 2,122
Investment, Identifier [Axis]: Creek Parent, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 15,225 0
Investment, Identifier [Axis]: Crewline Buyer, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 4,573 4,573
Investment, Identifier [Axis]: Delta Leasing SPV II LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 11,419
Investment, Identifier [Axis]: Draken International, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 22,175 0
Investment, Identifier [Axis]: Dukes Root Control Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 998 853
Investment, Identifier [Axis]: Entrata, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 5,211 5,211
Investment, Identifier [Axis]: Enverus Holdings, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 4,852 6,567
Investment, Identifier [Axis]: Establishment Labs Holdings Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 1,689 3,378
Investment, Identifier [Axis]: Everbridge, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 19,899 19,899
Investment, Identifier [Axis]: Evergreen IX Borrower 2023, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 4,006 4,006
Investment, Identifier [Axis]: Eyesouth Eye Care Holdco LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 4,467 4,835
Investment, Identifier [Axis]: F&M BUYER LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 11,435 0
Investment, Identifier [Axis]: Finastra USA, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,637 2,436
Investment, Identifier [Axis]: Galileo Parent, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,305 991
Investment, Identifier [Axis]: Geo Topco Corporation    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 16,967 0
Investment, Identifier [Axis]: Grand River Aseptic Manufacturing, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 9,237 0
Investment, Identifier [Axis]: Grove Hotel Parcel Owner, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 1,768 1,768
Investment, Identifier [Axis]: Harrow, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 4,301
Investment, Identifier [Axis]: IW Buyer LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 7,336 7,504
Investment, Identifier [Axis]: Icefall Parent, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 2,662 2,662
Investment, Identifier [Axis]: Integrity Marketing Acquisition, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 28,645 48,889
Investment, Identifier [Axis]: Inventus Power, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 4,139 4,967
Investment, Identifier [Axis]: Janus Bidco Limited    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 15,760 15,793
Investment, Identifier [Axis]: Kairos Intermediateco AB    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 66,921 0
Investment, Identifier [Axis]: Kings Buyer, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 5,492 3,329
Investment, Identifier [Axis]: Kite Midco II Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 9,609 0
Investment, Identifier [Axis]: LDS Buyer, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 14,106 0
Investment, Identifier [Axis]: LSL Holdco, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 162 244
Investment, Identifier [Axis]: Legends Hospitality Holding Company, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 6,207 9,820
Investment, Identifier [Axis]: Lightbox Intermediate, L.P.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,845 0
Investment, Identifier [Axis]: MRI Software LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 6,482 10,716
Investment, Identifier [Axis]: Microf Funding V LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 11,472 8,670
Investment, Identifier [Axis]: Minotaur Acquisition, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 11,132 11,132
Investment, Identifier [Axis]: Monotype Imaging Holdings Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 13,501 15,061
Investment, Identifier [Axis]: NFM & J, L.P.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 14,651 16,947
Investment, Identifier [Axis]: Nellson Nutraceutical, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 10,068 0
Investment, Identifier [Axis]: Neptune Bidco US Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 6,863 6,863
Investment, Identifier [Axis]: Next Holdco, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 16,443 16,443
Investment, Identifier [Axis]: North Star Acquisitionco, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 6,962 14,066
Investment, Identifier [Axis]: OneOncology, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 65,433 10,470
Investment, Identifier [Axis]: Optimizely North America Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 7,109 0
Investment, Identifier [Axis]: Oranje Holdco, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 1,968 1,968
Investment, Identifier [Axis]: PAI Financing Merger Sub LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 15,790 0
Investment, Identifier [Axis]: PPW Aero Buyer, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 16,633 26,797
Investment, Identifier [Axis]: PetVet Care Centers, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 19,210 19,210
Investment, Identifier [Axis]: Pluralsight, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,351 3,351
Investment, Identifier [Axis]: Poseidon Midco AB    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 32,131 32,272
Investment, Identifier [Axis]: Project Accelerate Parent, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 6,250 6,250
Investment, Identifier [Axis]: Propio LS, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 1,029 0
Investment, Identifier [Axis]: Protein for Pets Opco, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 4,847 6,639
Investment, Identifier [Axis]: Quantum Bidco Limited    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 24,898
Investment, Identifier [Axis]: RWK Midco AB    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 35,762 0
Investment, Identifier [Axis]: SEI Holding I Corporation    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 14,400 14,608
Investment, Identifier [Axis]: Salus Workers' Compensation, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 531 1,898
Investment, Identifier [Axis]: Sierra Enterprises, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 7,264 0
Investment, Identifier [Axis]: Sorenson Communications, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 10,177 10,177
Investment, Identifier [Axis]: Spruce Bidco I Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 26,341 0
Investment, Identifier [Axis]: SumUp Holdings Luxembourg    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 12,795 12,795
Investment, Identifier [Axis]: Supreme Fitness Group NY Holdings, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 0 396
Investment, Identifier [Axis]: TBRS, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 15,397 0
Investment, Identifier [Axis]: THG Acquisition, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 16,211 0
Investment, Identifier [Axis]: Telephone and Data Systems, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 18,568 18,569
Investment, Identifier [Axis]: Transit Buyer LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 1,951 520
Investment, Identifier [Axis]: Truck-Lite Co., LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 39,749 13,454
Investment, Identifier [Axis]: USIC Holdings, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 5,005 5,692
Investment, Identifier [Axis]: Usalco LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,269 3,269
Investment, Identifier [Axis]: Verona Pharma, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 9,011 29,285
Investment, Identifier [Axis]: Violin Finco Guernsey Limited    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 3,933 3,933
Investment, Identifier [Axis]: WP CPP Holdings, LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 5,831 5,831
Investment, Identifier [Axis]: West Star Aviation Acquisition LLC    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment 21,276 0
Investment, Identifier [Axis]: iCIMs, Inc.    
Financial Support for Nonconsolidated Legal Entity [Line Items]    
Unfunded Commitment $ 1,176 $ 3,710