INVESTMENTS IN LOANS AND SECURITIES - Schedule of Investments in Loans and Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 1,150,767		$ 811,874
Gross Unrealized Gains	13,783		19,313
Gross Unrealized Losses	(74,995)		(13,436)
Allowance for Credit Losses	(178,130)	$ (126,360)	(100,958)	$ (78,327)	$ (68,347)	$ 0
Fair Value	911,425		716,793
Accrued interest receivable	$ 13,600		$ 12,500
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Fees and other receivables (including related party receivables of $55,549 and $51,036 as of June 30, 2024 and December 31, 2023, respectively)		Fees and other receivables (including related party receivables of $55,549 and $51,036 as of June 30, 2024 and December 31, 2023, respectively)
Securitization notes
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 249,373		$ 91,654
Gross Unrealized Gains	469		629
Gross Unrealized Losses	(1,156)		(1,858)
Allowance for Credit Losses	0	0	0	0	0	0
Fair Value	248,686		90,425
Securitization certificates
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	893,351		715,646
Gross Unrealized Gains	13,314		18,684
Gross Unrealized Losses	(73,839)		(11,578)
Allowance for Credit Losses	(174,077)	(121,349)	(98,679)	(74,287)	(65,572)	0
Fair Value	658,749		624,073
Other loans and receivables
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	8,043		4,574
Gross Unrealized Gains	0		0
Gross Unrealized Losses	0		0
Allowance for Credit Losses	(4,053)	$ (5,011)	(2,279)	$ (4,040)	$ (2,775)	$ 0
Fair Value	$ 3,990		$ 2,295