REAL ESTATE AND OTHER SECURITIES (AS RESTATED) - Summary of Real Estate Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 18,562,039	$ 18,112,783
Carrying Value	$ 9,337,159	7,952,889	$ 9,201,474	$ 8,722,018
Weighted Average Life (Years)	4 years
Investments	$ 24,842,688	23,742,231
Residual Bonds
Debt Securities, Available-for-sale [Line Items]
Investments	30,500
Non-Agency Bonds
Debt Securities, Available-for-sale [Line Items]
Investments	1,000
AFS Agency
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	74,639	80,261
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Carrying Value	$ 65,496	$ 73,439
Number of Securities | security	1	1
Weighted Average Coupon	3.50%	3.50%
Weighted Average Yield	3.50%	3.50%
Weighted Average Life (Years)	10 years 9 months 18 days	8 years 10 months 24 days
AFS Non-Agency
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 2,446,762	$ 2,598,679
Gross Unrealized Gains	68,624	72,354
Gross Unrealized Losses	(24,488)	(33,684)
Carrying Value	$ 337,427	$ 369,055
Number of Securities | security	308	310
Weighted Average Coupon	3.40%	3.40%
Weighted Average Yield	3.80%	3.40%
Weighted Average Life (Years)	5 years	6 years 1 month 6 days
FVO Agency
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 8,515,621	$ 7,383,261
Gross Unrealized Gains	121,771	91,770
Gross Unrealized Losses	(5,666)	(43,826)
Carrying Value	$ 8,467,634	$ 7,264,978
Number of Securities | security	43	35
Weighted Average Coupon	5.20%	5.00%
Weighted Average Yield	5.20%	5.00%
Weighted Average Life (Years)	8 years 2 months 12 days	8 years 7 months 6 days
FVO Non-Agency
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 7,525,017	$ 8,050,582
Gross Unrealized Gains	20,681	17,374
Gross Unrealized Losses	(39,661)	(47,441)
Carrying Value	$ 466,602	$ 245,417
Number of Securities | security	314	222
Weighted Average Coupon	4.00%	1.90%
Weighted Average Yield	6.80%	3.20%
Weighted Average Life (Years)	6 years 10 months 24 days	4 years 4 months 24 days
Agency And Non-Agency Residential Mortgage Backed Securities
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 18,562,039	$ 18,112,783
Gross Unrealized Gains	211,076	181,498
Gross Unrealized Losses	(69,815)	(124,951)
Carrying Value	$ 9,337,159	$ 7,952,889
Number of Securities | security	666	568
Weighted Average Coupon	5.00%	4.80%
Weighted Average Yield	5.20%	4.90%
Weighted Average Life (Years)	8 years	8 years 4 months 24 days
Agency RMBS
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 8,590,260	$ 7,463,522
Agency RMBS | Fixed Rate Securities
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	8,600,000	7,500,000
Non-Agency RMBS
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	9,971,779	10,649,261
Non-Agency RMBS | Fixed Rate Securities
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	7,600,000	8,300,000
Residual and interest - only notional amount	6,900,000	7,500,000
Non-Agency RMBS | Floating Rate Securities
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	2,400,000	2,400,000
Residual and interest - only notional amount	2,100,000	2,300,000
Corporate debt
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount		514
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Carrying Value		$ 465
Number of Securities | security		2
Weighted Average Coupon		8.20%
Weighted Average Yield		9.50%
Weighted Average Life (Years)		2 years 2 months 12 days
Consumer loan bonds
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	239	$ 518
Gross Unrealized Gains	640	522
Gross Unrealized Losses	0	0
Carrying Value	$ 640	$ 590
Number of Securities | security	1	3
Weighted Average Life (Years)	1 year 8 months 12 days	8 months 12 days
Interest-only securities
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 3,833,797	$ 4,382,002
Gross Unrealized Gains	7,275	9,683
Gross Unrealized Losses	(24,312)	(25,795)
Carrying Value	$ 73,110	$ 94,830
Number of Securities | security	113	111
Weighted Average Coupon	1.00%	1.00%
Weighted Average Yield	10.20%	1.20%
Weighted Average Life (Years)	2 years 6 months	2 years 6 months
Servicing strips
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 2,469,571	$ 2,645,546
Gross Unrealized Gains	3,876	2,274
Gross Unrealized Losses	(645)	(926)
Carrying Value	$ 20,855	$ 21,206
Number of Securities | security	50	50
Weighted Average Coupon	0.00%	0.00%
Weighted Average Yield	14.80%	5.30%
Weighted Average Life (Years)	7 years 2 months 12 days	6 years 2 months 12 days
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 3,845
Gross Unrealized Gains	91
Gross Unrealized Losses	0
Carrying Value	$ 3,812
Number of Securities | security	2
Weighted Average Coupon	7.90%
Weighted Average Yield	8.60%
Weighted Average Life (Years)	1 year 4 months 24 days
CLOs
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 244,336
Gross Unrealized Gains	2,896
Gross Unrealized Losses	(44)
Carrying Value	$ 226,486
Number of Securities | security	88
Weighted Average Coupon	5.70%
Weighted Average Yield	6.10%
Weighted Average Life (Years)	9 years 1 month 6 days