Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Mar. 31, 2023		Sep. 30, 2022
Assets
Investments, at fair value	$ 5,486,352	[1]	$ 5,446,356	[2]
Cash and cash equivalents	76,757		117,290
Foreign currencies (cost of $10,547 and $7,021, respectively)	10,716		6,847
Restricted cash and cash equivalents	50,223		56,416
Interest receivable	31,240		20,794
Net unrealized appreciation on forward currency contracts	15,438		32,333
Other assets	1,024		1,188
Total Assets	5,671,750		5,681,224
Liabilities
Debt	3,116,857		3,093,603
Less unamortized debt issuance costs	(19,154)		(17,211)
Debt less unamortized debt issuance costs	3,097,703		3,076,392
Interest payable	23,574		20,384
Management and incentive fees payable	36,653		33,430
Accrued trustee fees	38		225
Accounts payable and other liabilities	7,637		6,293
Total Liabilities	3,165,605		3,136,724
Commitments and Contingencies (Note 8)
Net Assets
Preferred stock, par value $0.001 per share, 1,000,000 shares authorized, zero shares issued and outstanding as of March 31, 2023 and September 30, 2022	0		0
Common stock, par value $0.001 per share, 350,000,000 shares authorized, 170,144,126 and 170,895,670 shares issued and outstanding as of March 31, 2023 and September 30, 2022, respectively.	170		171
Paid in capital in excess of par	2,667,028		2,676,674
Distributable earnings (losses)	(161,053)		(132,345)
Total Net Assets	2,506,145		2,544,500
Total Liabilities and Total Net Assets	$ 5,671,750		$ 5,681,224
Number of common shares outstanding (in shares)	170,144,126		170,895,670
Net asset value per common share (in dollars per share)	$ 14.73		$ 14.89
Non-controlled/non-affiliate company investments
Assets
Investments, at fair value	$ 5,429,604	[1]	$ 5,374,594	[2]
Non-controlled affiliate company investments
Assets
Investments, at fair value	43,056	[1],[3]	57,689	[2],[4]
Controlled affiliate company investments
Assets
Investments, at fair value	$ 13,692	[1],[5]	$ 14,073	[2],[6]

[1] The fair values of investments were valued using significant unobservable inputs, unless noted otherwise. See Note 6. Fair Value Measurements.

[2] The fair values of investments were valued using significant unobservable inputs, unless noted otherwise. See Note 6. Fair Value Measurements.

[3] As defined in the 1940 Act, the Company is deemed to be an “affiliated person” of the portfolio company as the Company owns five percent or more of the portfolio company's voting securities (“non-controlled affiliate”). Transactions related to investments in non-controlled affiliates for the six months ended March 31, 2023 were as follows: Portfolio CompanyFair value as of September 30, 2022 Gross Additions(a) Gross Reductions(b) Net change in unrealized gain (loss)Net realized gain (loss)Fair value as of March 31, 2023Interest, dividend and fee incomeAbita Brewing Co. LLC$8,071 $675 $(472)$(2,151)$— $6,123 $373 Benetech, Inc.1,740 321 (257)(167)— 1,637 9 Elite Dental Partners LLC20,689 2,634 (18)(7,051)— 16,254 943 Rubio's Restaurants, Inc13,174 1,783 — (3,401)— 11,556 922 Sloan Company, Inc.6,318 38 (6,329)(347)320 — 344 Switchfly LLC7,697 144 — (355)— 7,486 69 Total Non-Controlled Affiliates$57,689 $5,595 $(7,076)$(13,472)$320 $43,056 $2,660  (a) Gross additions may include increases in the cost basis of investments resulting from new investments, amounts related to PIK interest capitalized and added to the principal balance of the respective loans, the accretion of discounts, the exchange of one or more existing investments for one or more new investments and the movement of an existing portfolio company into this affiliated category from a different category. (b) Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments and sales, the amortization of premiums, the reversal of capitalized PIK for non-accrual positions and the exchange of one or more existing securities for one or more new securities.

[4] Transactions related to investments in non-controlled affiliates for the year ended September 30, 2022 were as follows: Portfolio Company Fair value as of September 30, 2021 Gross Additions(a) Gross Reductions(b) Net change in unrealized gain (loss)Net realized gain (loss)Fair value as of September 30, 2022Interest, dividend and fee incomeAbita Brewing Co. LLC$10,050 $413 $(212)$(2,180)$— $8,071 $823  Benetech, Inc. 2,399 2,821 (2,512)(968)— 1,740 227 Elite Dental Partners LLC16,952 4,151 (60)(354)— 20,689 1,313 Paradigm DKD Group, LLC2,627 357 (3,605)(571)1,192 — 2,026 Rubio's Restaurants, Inc17,559 4 (44)(4,345)— 13,174 1,379 Sloan Company, Inc.5,162 1,520 (648)284 — 6,318 127  Switchfly LLC 6,168 1,321 — 208 — 7,697 603  Uinta Brewing Company 462 22 (498)1,040 (1,026)— 6  Total Non-Controlled Affiliates $61,379 $10,609 $(7,579)$(6,886)$166 $57,689 $6,504  (a) Gross additions may include increases in the cost basis of investments resulting from new investments, amounts related to PIK interest capitalized and added to the principal balance of the respective loans, the accretion of discounts, the exchange of one or more existing investments for one or more new investments and the movement of an existing portfolio company into this affiliated category from a different category. (b) Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments and sales, the amortization of premiums, the reversal of capitalized PIK for non-accrual positions and the exchange of one or more existing securities for one or more new securities.

[5] As defined in the 1940 Act, the Company is deemed to be both an “affiliated person” of and “control” this portfolio company as the Company owns more than 25% of the portfolio company's outstanding voting securities or has the power to exercise control over management or policies of such portfolio company (including through a management agreement) (“controlled affiliate”). Transactions related to investments in controlled affiliates for the six months ended March 31, 2023 were as follows: Portfolio CompanyFair value as of September 30, 2022 Gross Additions(a) Gross Reductions(b) Net change in unrealized gain (loss)Net realized gain (loss)Fair value as of March 31, 2023Interest, dividend and fee incomeMMan Acquisition Co.$14,073 $1,018 $(820)$(579)$— $13,692 $142 Total Controlled Affiliates$14,073 $1,018 $(820)$(579)$— $13,692 $142  (a) Gross additions may include increases in the cost basis of investments resulting from new investments, amounts related to PIK interest capitalized and added to the principal balance of the respective loans, the accretion of discounts, the exchange of one or more existing investments for one or more new investments and the movement of an existing portfolio company into this affiliated category from a different category. (b) Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the amortization of premiums, the reversal of capitalized PIK for non-accrual positions and the exchange of one or more existing securities for one or more new securities.

[6] Transactions related to investments in controlled affiliates for the year ended September 30, 2022 were as follows: Portfolio Company Fair value as of September 30, 2021 Gross Additions(a) Gross Reductions(b) Net change in unrealized gain (loss)Net realized gain (loss)Fair value as of September 30, 2022Interest, dividend and fee incomeMMan Acquisition Co.$18,237 $4,956 $(2,996)$(6,124)$— $14,073 $102  Total Controlled Affiliates $18,237 $4,956 $(2,996)$(6,124)$— $14,073 $102  (a) Gross additions may include increases in the cost basis of investments resulting from new investments, amounts related to PIK interest capitalized and added to the principal balance of the respective loans, the accretion of discounts, the exchange of one or more existing investments for one or more new investments and the movement of an existing portfolio company into this affiliated category from a different category. (b) Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the amortization of premiums, the reversal of capitalized PIK for non-accrual positions and the exchange of one or more existing securities for one or more new securities.