FAIR VALUE MEASUREMENT - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands		Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Assets:
Investments in loans and securities	[1]	$ 887,736		$ 778,409
Liabilities:
Warrant liability		7,379	$ 2,471	893	$ 2,884	$ 1,671	$ 3,242
Other liabilities		8,715		6,090
Accrued interest receivable		21,700		14,300
Level 1
Liabilities:
Warrant liability		7,379		890
Other liabilities		0		0
Level 2
Liabilities:
Warrant liability		0		3
Other liabilities		0		0
Level 3
Liabilities:
Warrant liability		0		0
Other liabilities		8,715		6,090
Notes
Assets:
Investments in loans and securities		344,763		240,274
Notes | Level 1
Assets:
Investments in loans and securities		0		0
Notes | Level 2
Assets:
Investments in loans and securities		135,272		115,220
Notes | Level 3
Assets:
Investments in loans and securities		209,491		125,054
Certificates
Assets:
Investments in loans and securities		541,363		533,243
Certificates | Level 1
Assets:
Investments in loans and securities		0		0
Certificates | Level 2
Assets:
Investments in loans and securities		0		0
Certificates | Level 3
Assets:
Investments in loans and securities		$ 541,363		$ 533,243

[1] Accrued interest receivable of $14.3 million, previously reported within “Fee receivables” as of December 31, 2024, has been reclassified to “Investment in loans and securities” to conform to the current period’s presentation.