SECURED FINANCING - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Repurchase Agreements:
Netted amounts	$ 61,659,460	$ 65,688,923	[1]
Repurchase agreements, weighted average remaining maturities	50 days	32 days
Repurchase agreements weighted average rate	4.56%	4.76%
Repurchase agreement amount	$ 3,900,000
Remaining capacity of repurchase agreement	2,200,000
Fair value of collateral received for reverse repurchase agreements	2,500,000	$ 2,600,000
Fair value of securities sold	2,500,000	2,500,000
Other secured financing	$ 900,000	$ 750,000	[1]
Debt weighted average interest rate	7.03%	7.21%
Secured financings and interest rate swaps - collateral held, estimated fair value	$ 68,000,000	$ 71,800,000
Secured financings and interest rate swaps - collateral held, accrued interest	310,100	332,700
Line of Credit | Mortgage Servicing Rights Committed Credit Facility
Repurchase Agreements:
Credit facility, maximum borrowing capacity	$ 1,800,000	$ 1,600,000
Minimum
Repurchase Agreements:
Debt instrument, maturity	1 year	1 month
Maximum
Repurchase Agreements:
Debt instrument, maturity	2 years	2 years

[1] (1)Derived from the audited consolidated financial statements at December 31, 2024.