Investments - Schedule of Investments by Industry Classification and Enumerates Percentage, by Fair Value, of Total Portfolio Assets Excluding Cash and Cash Equivalents (Details)	Mar. 31, 2023	Sep. 30, 2022
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	100.00%	100.00%
Media
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	9.00%	7.00%
Professional Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	7.00%	9.00%
IT Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	7.00%	6.00%
Commercial Services & Supplies
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	6.00%	5.00%
Personal Products
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	5.00%	7.00%
Media: Diversified and Production
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	5.00%	5.00%
High Tech Industries
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	5.00%	5.00%
Aerospace and Defense
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	5.00%	4.00%
Diversified Consumer Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	5.00%	4.00%
Capital Equipment
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	4.00%	4.00%
Healthcare Technology
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	4.00%	4.00%
Electronic Equipment, Instruments, and Components
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	3.00%	3.00%
Healthcare Providers and Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	3.00%	3.00%
Construction and Building
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	3.00%	3.00%
Insurance
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	2.00%
Diversified Financial Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	2.00%
Distributors
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	2.00%
Chemicals, Plastics and Rubber
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	2.00%
Healthcare Equipment and Supplies
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	2.00%
Media: Broadcasting and Subscription
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	2.00%
Business Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	3.00%
Hotels, Restaurants and Leisure
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	1.00%
Consumer Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	2.00%
Automobiles
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Energy Equipment and Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Financial Services
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Textiles, Apparel and Luxury Goods
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Leisure Products
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Construction & Engineering
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%
Air Freight and Logistics
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Banking, Finance, Insurance & Real Estate
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Food Products
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Wholesale
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	1.00%	1.00%
Building Products
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	0.00%	1.00%
All Other Industries
Investment Holdings [Line Items]
Fair value investments of portfolio assets excluding cash and cash equivalents percentage	2.00%	3.00%