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Transactions with Controlled Companies - MITY, Inc. (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
Realized (Loss) Gain		(223,719)	(518,682)	(417,443)
Interest Receivable		$ 17,350	25,144
MITY, Inc. \| MITY Holdings of Delaware Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%
MITY-Lite, Inc. \| MITY, Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%
Broda USA, Inc. \| MITY, Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%
Broda Enterprises ULC \| MITY, Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%
Reportable Legal Entities \| Subsidiaries \| MITY, Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income		$ 9,590	9,336	8,988
Structuring Fee		178	107	130
Total Other Income		178	107	130
Realized (Loss) Gain		19	12	(1)
Additions		7,123	4,265	5,150
Interest Receivable		27	26
Other Receivables		2	65
Reportable Legal Entities \| Subsidiaries \| MITY, Inc. \| Prospect Administration
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Managerial Assistance		450	376	300
Reimbursement of Legal, Tax, etc		$ 31	37	23
Reportable Legal Entities \| Subsidiaries \| MITY Holdings of Delaware Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%
Reportable Legal Entities \| Subsidiaries \| MITY, Inc. \| MITY, Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income		$ 9,052	8,801	8,434
Reportable Legal Entities \| Subsidiaries \| MITY FSC, Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%
Reportable Legal Entities \| Subsidiaries \| Borda Canada \| MITY, Inc.
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income		$ 538	$ 535	$ 554