FAIR VALUE MEASUREMENT - Schedule of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Assets:
Investments in loans and securities	$ 894,151	$ 716,793
Liabilities:
Warrant liability	1,342	3,242	$ 1,210	$ 1,400
Notes
Assets:
Investments in loans and securities	173,812	90,425
Certificates and Other loans and receivables
Assets:
Investments in loans and securities	720,339	626,368
Level 1
Liabilities:
Warrant liability	872	2,106
Level 1 | Notes
Assets:
Investments in loans and securities	0	0
Level 1 | Certificates and Other loans and receivables
Assets:
Investments in loans and securities	0	0
Level 2
Liabilities:
Warrant liability	470	1,136
Level 2 | Notes
Assets:
Investments in loans and securities	69,030	90,425
Level 2 | Certificates and Other loans and receivables
Assets:
Investments in loans and securities	0	0
Level 3
Liabilities:
Warrant liability	0	0
Level 3 | Notes
Assets:
Investments in loans and securities	104,782	0
Level 3 | Certificates and Other loans and receivables
Assets:
Investments in loans and securities	$ 720,339	$ 626,368