EXCESS MORTGAGE SERVICING RIGHTS - Schedule of Activity Related to the Carrying Value of Investments in Excess MSRs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Carrying Value of Investments in Excess MSRs
Beginning balance	$ 8,889,403	$ 6,858,803
Ending balance	$ 8,405,938	$ 8,889,403
Servicing Asset, Fair Value, Change in Fair Value, Other, Statement of Income or Comprehensive Income [Extensible Enumeration]	Realized and unrealized gains (losses), net	Realized and unrealized gains (losses), net
Excess MSRs
Carrying Value of Investments in Excess MSRs
Beginning balance	$ 249,366	$ 259,198
Interest income	18,310	38,035
Other income	267	42
Proceeds from repayments	(41,552)	(43,950)
Proceeds from sales	(2,779)	(997)
Change in fair value	(15,227)	(2,962)
Ending balance	$ 208,385	$ 249,366