Transactions with Controlled Companies - Pacific World Corporation (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Dec. 31, 2025	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2024
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income		$ 581,932	$ 671,109	$ 770,312
Structuring Fee		9,000	12,348	27,666
Total Other Income		10,555	28,949	79,397
Interest Receivable		17,350	25,144
Reportable Legal Entities \| Subsidiaries \| Pacific World Corporation
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income		9,775	9,865	10,164
Structuring Fee		418	286	812
Total Other Income		418	286	812
Additions		16,700	14,275	32,500
Interest Income Capitalized as PIK		8,126	6,317	9,021
Repayment of Loan Receivable		0	4,875	0
Interest Receivable		27	27
Other Receivables		197	155
Reportable Legal Entities \| Subsidiaries \| Pacific World Corporation \| Prospect Administration
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Reimbursement of Legal, Tax, etc		$ 0	$ 38	$ 5
Reportable Legal Entities \| Subsidiaries \| Pacific World Corporation
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Preferred equity ownership interest	100.00%	100.00%
Ownership interest	99.99%	99.99%

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