SECURED FINANCING - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Repurchase Agreements:
Netted amounts	$ 60,993,018	$ 59,512,597	[1]
Repurchase agreements - weighted average remaining maturities	59 days	27 days
Repurchase agreement amount	$ 2,000,000
Remaining capacity of repurchase agreement	1,300,000
Other secured financing	$ 250,000	$ 250,000	[1]
Debt weighted average interest rate	7.54%
Secured financings and interest rate swaps - collateral held, estimated fair value	$ 64,000,000	62,200,000
Secured financings and interest rate swaps - collateral held, accrued interest	235,800	$ 226,400
Line of Credit | Mortgage Servicing Rights Committed Credit Facility
Repurchase Agreements:
Credit facility, maximum borrowing capacity	$ 750,000
Minimum
Repurchase Agreements:
Debt instrument, maturity	1 year
Maximum
Repurchase Agreements:
Debt instrument, maturity	3 years

[1] (1)Derived from the audited consolidated financial statements at December 31, 2022.