Fair Value and Maturity of Debt Outstanding - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Jun. 30, 2022
Debt Instrument [Line Items]
Asset coverage ratio	306.20%	273.30%
Principal Outstanding	$ 2,481,277	$ 2,769,156
Asset coverage ratio on our senior security stock	193.20%	215.60%
Senior Notes
Debt Instrument [Line Items]
Principal Outstanding	$ 2,481,277	$ 2,769,156

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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