INVESTMENTS - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ (510,294)	$ (100,958)
Additions to allowance for credit losses not previously recorded	(26,431)	(2,965)
Additions to allowance for credit losses arising from purchases		(3,246)
Reductions for securities sold during the period	78,355
Additions (reductions) on securities with previous allowance	(8,586)	(20,640)
Write-offs charged against the allowance	436	1,449
Balance at end of period	(466,520)	(126,360)
Securitization notes
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	0	0
Additions to allowance for credit losses not previously recorded	(2,873)	0
Additions to allowance for credit losses arising from purchases		0
Reductions for securities sold during the period	0
Additions (reductions) on securities with previous allowance	0	0
Write-offs charged against the allowance	0	0
Balance at end of period	(2,873)	0
Securitization certificates
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	(508,741)	(98,679)
Additions to allowance for credit losses not previously recorded	(23,558)	(2,965)
Additions to allowance for credit losses arising from purchases		0
Reductions for securities sold during the period	78,355
Additions (reductions) on securities with previous allowance	(8,492)	(19,705)
Write-offs charged against the allowance	0	0
Balance at end of period	(462,436)	(121,349)
Other loans and receivables
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	(1,553)	(2,279)
Additions to allowance for credit losses not previously recorded	0	0
Additions to allowance for credit losses arising from purchases		(3,246)
Reductions for securities sold during the period	0
Additions (reductions) on securities with previous allowance	(94)	(935)
Write-offs charged against the allowance	436	1,449
Balance at end of period	$ (1,211)	$ (5,011)