GOVERNMENT AND GOVERNMENT-BACKED SECURITIES - Summary of Real Estate Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) security	Dec. 31, 2023 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 15,878,274	$ 18,562,039
Carrying Value	$ 7,245,667	9,337,159
Weighted Average Life (Years)	3 years 7 months 6 days
AFS Agency
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 69,295	74,639
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Carrying Value	$ 60,135	$ 65,496
Number of Securities | security	1	1
Weighted Average Coupon	3.50%	3.50%
Weighted Average Yield	3.50%	3.50%
Weighted Average Life (Years)	7 years 9 months 18 days	10 years 9 months 18 days
FVO Agency
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 6,602,894	$ 8,515,621
Gross Unrealized Gains	428	121,771
Gross Unrealized Losses	(51,024)	(5,666)
Carrying Value	$ 6,390,508	$ 8,467,634
Number of Securities | security	42	43
Weighted Average Coupon	5.00%	5.20%
Weighted Average Yield	5.00%	5.20%
Weighted Average Life (Years)	5 years 8 months 12 days	8 years 2 months 12 days
FVO Non-Agency
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 3,250,000
Gross Unrealized Gains	4,102
Gross Unrealized Losses	(781)
Carrying Value	$ 3,260,703
Number of Securities | security	3
Weighted Average Coupon	4.50%
Weighted Average Yield	4.50%
Weighted Average Life (Years)	1 year 10 months 24 days
Agency And Non-Agency Residential Mortgage Backed Securities
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 9,922,189	$ 8,590,260
Gross Unrealized Gains	4,530	121,771
Gross Unrealized Losses	(51,805)	(5,666)
Carrying Value	$ 9,711,346	$ 8,533,130
Number of Securities | security	46	44
Weighted Average Coupon	4.80%	5.20%
Weighted Average Yield	4.80%	5.20%
Weighted Average Life (Years)	4 years 4 months 24 days	8 years 2 months 12 days