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Transactions with Controlled Companies - Credit Central Loan Company, LLC (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Jun. 30, 2026
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income	$ 132,608	$ 152,394
Interest Receivable	$ 23,039		$ 17,350
Credit Central Loan Company, LLC \| Credit Central Holdings of Delaware, LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	99.80%		99.80%
Credit Central, LLC \| Credit Central Loan Company, LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%		100.00%
Credit Central South, LLC \| Credit Central Loan Company, LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%		100.00%
Credit Central of Texas, LLC \| Credit Central Loan Company, LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%		100.00%
Credit Central of Tennessee, LLC \| Credit Central Loan Company, LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%		100.00%
Reportable Legal Entities \| Subsidiaries \| Credit Central Loan Company, LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Interest Income	$ 1,371	2,304
Additions	1,398	2,315
Interest Receivable	(11)		$ 15
Other Receivables	83		$ 79
Reportable Legal Entities \| Subsidiaries \| Credit Central Loan Company, LLC \| Prospect Administration
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Managerial Assistance	175	175
Reimbursement of Legal, Tax, etc	$ 12	$ 0
Reportable Legal Entities \| Subsidiaries \| Credit Central Holdings of Delaware, LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest	100.00%		100.00%