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Amount of fees and commissions from banking, advisory, brokerage, and securities underwriting activities. Activities include, but are not limited to, underwriting securities, private placements of securities, investment advisory and management services, merger and acquisition services, sale and servicing of mutual funds, and other related consulting fees.

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Transactions with Controlled Companies - First Tower Finance Company LLC (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
First Tower Finance Company LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest		78.06%
First Tower Finance Company LLC \| First Tower Holdings of Delaware LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	80.10%	80.10%
First Tower, LLC \| First Tower Finance Company LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%
Reportable Legal Entities \| Subsidiaries \| First Tower Holdings of Delaware LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Additions		$ 10,928	17,501	0
Interest Income Capitalized as PIK		31	10,115	29,385
Repayment of Loan Receivable		2,867	437	319
Interest Receivable		205	189
Other Receivables		4	96
Reportable Legal Entities \| Subsidiaries \| First Tower Finance Company LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income		71,975	65,954	62,675
Structuring Fee		328	421	0
Total Other Income		328	421	0
Reportable Legal Entities \| Subsidiaries \| First Tower Finance Company LLC \| Prospect Administration
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Managerial Assistance		2,400	2,400	2,400
Reimbursement of Legal, Tax, etc		$ 13	$ 0	$ 0
Reportable Legal Entities \| First Tower Holdings of Delaware LLC \| Subsidiaries
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%	100.00%