FAIR VALUE MEASUREMENT - Schedule of Financial Assets and Liabilities Not Recorded at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Assets:
Cash and cash equivalents, and restricted cash and cash equivalents	$ 264,767	$ 226,518
Fees receivables	154,976	127,114
Investments in other loans and receivables	1,610	4,893
Liabilities:
Accrued interest receivable	21,700	14,300
Secured borrowing
Liabilities:
Long-term debt	133,667	177,554
Exchangeable notes
Liabilities:
Long-term debt	381,382	163,360
Long-term debt
Liabilities:
Long-term debt	466,180	366,396
Carrying Value
Assets:
Cash and cash equivalents, and restricted cash and cash equivalents	264,767	226,518
Fees receivables	154,976	127,114
Investments in other loans and receivables	1,610	4,893
Carrying Value | Secured borrowing
Liabilities:
Long-term debt	131,525	176,089
Carrying Value | Exchangeable notes
Liabilities:
Long-term debt	148,148	146,342
Carrying Value | Long-term debt
Liabilities:
Long-term debt	487,789	321,317
Fair Value | Level 1
Assets:
Cash and cash equivalents, and restricted cash and cash equivalents	264,767	226,518
Fees receivables	0	0
Investments in other loans and receivables	0	0
Fair Value | Level 1 | Secured borrowing
Liabilities:
Long-term debt	0	0
Fair Value | Level 1 | Exchangeable notes
Liabilities:
Long-term debt	0	0
Fair Value | Level 1 | Long-term debt
Liabilities:
Long-term debt	0	0
Fair Value | Level 2
Assets:
Cash and cash equivalents, and restricted cash and cash equivalents	0	0
Fees receivables	79,154	63,143
Investments in other loans and receivables	0	0
Fair Value | Level 2 | Secured borrowing
Liabilities:
Long-term debt	0	0
Fair Value | Level 2 | Exchangeable notes
Liabilities:
Long-term debt	381,382	163,360
Fair Value | Level 2 | Long-term debt
Liabilities:
Long-term debt	466,180	0
Fair Value | Level 3
Assets:
Cash and cash equivalents, and restricted cash and cash equivalents	0	0
Fees receivables	75,822	63,971
Investments in other loans and receivables	1,610	4,893
Fair Value | Level 3 | Secured borrowing
Liabilities:
Long-term debt	133,667	177,554
Fair Value | Level 3 | Exchangeable notes
Liabilities:
Long-term debt	0	0
Fair Value | Level 3 | Long-term debt
Liabilities:
Long-term debt	$ 0	$ 366,396