v3.26.1
Investments - Schedule of Portfolio Composition by Industry at Amortization Cost and Fair Value (Details) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Jun. 30, 2026
Sep. 30, 2025
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 8,377,113 $ 8,759,938
Investments, at fair value $ 8,196,353 [1] $ 8,769,389 [2]
Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 100.00% 100.00%
Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 100.00% 100.00%
Aerospace & Defense    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 58,461 $ 54,719
Investments, at fair value $ 58,686 $ 54,528
Aerospace & Defense | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.70% 0.60%
Aerospace & Defense | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.70% 0.60%
Air Freight & Logistics    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 52,911 $ 52,825
Investments, at fair value $ 54,334 $ 54,006
Air Freight & Logistics | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.60% 0.60%
Air Freight & Logistics | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.70% 0.60%
Airlines    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 0 $ 8,930
Investments, at fair value $ 0 $ 9,085
Airlines | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.10%
Airlines | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.10%
Auto Components    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 34,860 $ 39,106
Investments, at fair value $ 32,490 $ 32,910
Auto Components | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Auto Components | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Automobiles    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 382,509 $ 418,536
Investments, at fair value $ 379,358 $ 417,389
Automobiles | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 4.60% 4.80%
Automobiles | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 4.60% 4.80%
Banks    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 13,834 $ 12,895
Investments, at fair value $ 13,421 $ 12,951
Banks | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.10%
Banks | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.10%
Beverages    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 80,541 $ 79,802
Investments, at fair value $ 70,200 $ 71,405
Beverages | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.00% 0.90%
Beverages | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.90% 0.80%
Biotechnology    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 2,000 $ 2,000
Investments, at fair value $ 101 $ 149
Biotechnology | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.00%
Biotechnology | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.00%
Building Products    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 64,580 $ 62,749
Investments, at fair value $ 63,633 $ 62,640
Building Products | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.80% 0.70%
Building Products | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.80% 0.70%
Capital Markets    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 14,157 $ 14,049
Investments, at fair value $ 13,999 $ 14,115
Capital Markets | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Capital Markets | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Chemicals    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 148,806 $ 142,340
Investments, at fair value $ 141,814 $ 137,323
Chemicals | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.80% 1.60%
Chemicals | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.70% 1.60%
Commercial Services & Supplies    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 178,620 $ 217,458
Investments, at fair value $ 178,629 $ 219,594
Commercial Services & Supplies | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.10% 2.50%
Commercial Services & Supplies | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.20% 2.50%
Communications Equipment    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 16,537 $ 16,529
Investments, at fair value $ 16,289 $ 16,585
Communications Equipment | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Communications Equipment | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Construction & Engineering    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 14,248 $ 12,648
Investments, at fair value $ 14,181 $ 12,728
Construction & Engineering | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.10%
Construction & Engineering | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.10%
Containers & Packaging    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 125,389 $ 111,514
Investments, at fair value $ 123,586 $ 111,548
Containers & Packaging | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.50% 1.30%
Containers & Packaging | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.50% 1.30%
Diversified Consumer Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 466,908 $ 466,558
Investments, at fair value $ 457,787 $ 462,485
Diversified Consumer Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 5.60% 5.30%
Diversified Consumer Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 5.60% 5.30%
Diversified Financial Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 188,047 $ 171,432
Investments, at fair value $ 187,906 $ 175,762
Diversified Financial Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.20% 2.00%
Diversified Financial Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.30% 2.00%
Diversified Telecommunication Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 830 $ 1,525
Investments, at fair value $ 832 $ 1,529
Diversified Telecommunication Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.00%
Diversified Telecommunication Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.00%
Electric Utilities    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 7,326 $ 7,093
Investments, at fair value $ 7,703 $ 7,445
Electric Utilities | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.10%
Electric Utilities | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.10%
Electrical Equipment    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 0 $ 25,139
Investments, at fair value $ 0 $ 25,587
Electrical Equipment | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.30%
Electrical Equipment | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.30%
Electronic Equipment, Instruments & Components    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 32,915 $ 33,484
Investments, at fair value $ 33,022 $ 34,220
Electronic Equipment, Instruments & Components | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Electronic Equipment, Instruments & Components | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Energy Equipment & Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 4,302 $ 4,355
Investments, at fair value $ 2,126 $ 2,089
Energy Equipment & Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.00%
Energy Equipment & Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.00%
Food & Staples Retailing    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 35,571 $ 30,214
Investments, at fair value $ 34,030 $ 30,171
Food & Staples Retailing | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.30%
Food & Staples Retailing | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.30%
Food Products    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 226,789 $ 225,050
Investments, at fair value $ 227,651 $ 231,437
Food Products | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.70% 2.60%
Food Products | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.80% 2.60%
Healthcare Equipment & Supplies    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 266,386 $ 325,894
Investments, at fair value $ 268,661 $ 332,338
Healthcare Equipment & Supplies | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.20% 3.70%
Healthcare Equipment & Supplies | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.30% 3.80%
Healthcare Providers & Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 661,338 $ 650,544
Investments, at fair value $ 638,065 $ 645,551
Healthcare Providers & Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 7.90% 7.40%
Healthcare Providers & Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 7.80% 7.40%
Healthcare Technology    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 371,943 $ 401,952
Investments, at fair value $ 361,393 $ 406,376
Healthcare Technology | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 4.50% 4.60%
Healthcare Technology | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 4.40% 4.60%
Hotels, Restaurants & Leisure    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 282,892 $ 271,432
Investments, at fair value $ 283,282 $ 272,038
Hotels, Restaurants & Leisure | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.40% 3.10%
Hotels, Restaurants & Leisure | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.40% 3.10%
Household Durables    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 609 $ 0
Investments, at fair value $ 608 $ 0
Household Durables | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.00%
Household Durables | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.00%
Household Products    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 9,445 $ 9,511
Investments, at fair value $ 9,369 $ 9,564
Household Products | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.10%
Household Products | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.10%
Industrial Conglomerates    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 101,578 $ 84,797
Investments, at fair value $ 105,292 $ 90,985
Industrial Conglomerates | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.20% 1.00%
Industrial Conglomerates | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.30% 1.00%
Insurance    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 436,521 $ 425,336
Investments, at fair value $ 432,517 $ 426,028
Insurance | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 5.20% 4.90%
Insurance | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 5.30% 4.90%
Internet & Direct Marketing Retail    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 104,314 $ 103,716
Investments, at fair value $ 91,729 $ 87,060
Internet & Direct Marketing Retail | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.20% 1.20%
Internet & Direct Marketing Retail | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.10% 1.00%
IT Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 285,406 $ 280,208
Investments, at fair value $ 291,888 $ 292,679
IT Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.40% 3.20%
IT Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.50% 3.30%
Leisure Products    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 3,153 $ 14,582
Investments, at fair value $ 4,723 $ 16,174
Leisure Products | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.20%
Leisure Products | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.20%
Life Sciences Tools & Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 73,675 $ 126,213
Investments, at fair value $ 70,553 $ 128,419
Life Sciences Tools & Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.90% 1.40%
Life Sciences Tools & Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.90% 1.50%
Machinery    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 16,875 $ 30,878
Investments, at fair value $ 16,449 $ 30,896
Machinery | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.40%
Machinery | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.30%
Marine    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 34,104 $ 34,593
Investments, at fair value $ 32,966 $ 34,116
Marine | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Marine | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Media    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 19,298 $ 18,138
Investments, at fair value $ 18,990 $ 17,634
Media | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Media | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Multiline Retail    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 33,158 $ 32,524
Investments, at fair value $ 31,129 $ 33,243
Multiline Retail | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Multiline Retail | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.40% 0.40%
Oil, Gas & Consumable Fuels    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 2,725 $ 9,925
Investments, at fair value $ 1,123 $ 9,149
Oil, Gas & Consumable Fuels | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.10%
Oil, Gas & Consumable Fuels | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.00% 0.10%
Paper & Forest Products    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 17,838 $ 18,298
Investments, at fair value $ 18,183 $ 18,524
Paper & Forest Products | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Paper & Forest Products | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.20% 0.20%
Personal Products    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 24,926 $ 23,887
Investments, at fair value $ 21,635 $ 23,769
Personal Products | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.30% 0.30%
Personal Products | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.30% 0.30%
Pharmaceuticals    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 324,891 $ 321,121
Investments, at fair value $ 319,394 $ 322,002
Pharmaceuticals | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.90% 3.70%
Pharmaceuticals | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 3.90% 3.70%
Professional Services    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 212,728 $ 217,398
Investments, at fair value $ 208,591 $ 221,818
Professional Services | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.50% 2.50%
Professional Services | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 2.50% 2.50%
Real Estate Management & Development    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 112,495 $ 112,592
Investments, at fair value $ 110,789 $ 112,254
Real Estate Management & Development | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.30% 1.30%
Real Estate Management & Development | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 1.40% 1.30%
Road & Rail    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 41,731 $ 43,171
Investments, at fair value $ 40,693 $ 42,612
Road & Rail | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.50% 0.50%
Road & Rail | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.50% 0.50%
Software    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 2,183,912 $ 2,362,302
Investments, at fair value $ 2,135,050 $ 2,387,723
Software | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 26.10% 27.00%
Software | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 26.00% 27.20%
Specialty Retail    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 419,948 $ 450,181
Investments, at fair value $ 389,324 $ 436,744
Specialty Retail | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 5.00% 5.10%
Specialty Retail | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 4.70% 5.00%
Textiles, Apparel & Luxury Goods    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 43,124 $ 43,744
Investments, at fair value $ 43,299 $ 41,934
Textiles, Apparel & Luxury Goods | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.50% 0.50%
Textiles, Apparel & Luxury Goods | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.50% 0.50%
Trading Companies & Distributors    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 58,069 $ 56,605
Investments, at fair value $ 55,027 $ 52,247
Trading Companies & Distributors | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.70% 0.60%
Trading Companies & Distributors | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.70% 0.60%
Transportation Infrastructure    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 8,959 $ 8,904
Investments, at fair value $ 8,916 $ 8,856
Transportation Infrastructure | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.10%
Transportation Infrastructure | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.10% 0.10%
Water Utilities    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Amortized Cost: $ 74,931 $ 70,542
Investments, at fair value $ 74,937 $ 70,975
Water Utilities | Amortized Cost | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.90% 0.80%
Water Utilities | Fair Value | Industry Concentration Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value: 0.90% 0.80%
[1] The fair values of investments were valued using significant unobservable inputs, unless noted otherwise. See Note 6. The fair value of loan investments may include the impact of the unfunded commitment being valued below par.
[2] The fair values of investments were valued using significant unobservable inputs, unless noted otherwise. See Note 6. The fair value of loan investments may include the impact of the unfunded commitment being valued below par.