DEBT OBLIGATIONS - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Outstanding Face Amount	$ 23,562,807
Carrying Value	$ 23,458,626	$ 21,356,679	$ 29,237,694
Weighted Average Funding Cost	6.60%
Weighted Average Life (Years)	1 year 2 months 12 days
Interest payable	$ 149,552	87,700
Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	12,570,327
Carrying Value	$ 12,561,283	11,257,736
Weighted Average Funding Cost	6.10%
Weighted Average Life (Years)	7 months 6 days
Interest payable	$ 142,300
Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	10,770,230
Carrying Value	$ 10,679,186	10,098,943
Weighted Average Funding Cost	7.10%
Weighted Average Life (Years)	1 year 10 months 24 days
Warehouse Credit Facilities-Residential Mortgage Loans | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	$ 1,940,295
Carrying Value	$ 1,940,038	2,601,327
Weighted Average Funding Cost	6.80%
Weighted Average Life (Years)	7 months 6 days
Face amount of fixed rate debt	$ 233,900
Interest rate, stated percentage	5.00%
Warehouse Credit Facilities-Residential Mortgage Loans | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	21 years 6 months
Outstanding Face	$ 2,201,857
Amortized Cost Basis	2,315,385
Carrying Value	2,235,311
Warehouse Credit Facility- Mortgage Loans Receivable | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	1,337,010
Carrying Value	$ 1,337,010	1,220,662
Weighted Average Funding Cost	8.20%
Weighted Average Life (Years)	1 year 8 months 12 days
Warehouse Credit Facility- Mortgage Loans Receivable | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	1 year 2 months 12 days
Outstanding Face	$ 1,610,728
Amortized Cost Basis	1,609,242
Carrying Value	1,609,242
Agency RMBS or Treasuries | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	8,152,469
Carrying Value	$ 8,152,469	6,821,788
Weighted Average Funding Cost	5.50%
Weighted Average Life (Years)	2 months 12 days
Agency RMBS or Treasuries | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	8 years 2 months 12 days
Outstanding Face	$ 8,588,624
Amortized Cost Basis	8,415,294
Carrying Value	8,566,211
Non-Agency RMBS | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	610,189
Carrying Value	$ 610,189	609,282
Weighted Average Funding Cost	7.60%
Weighted Average Life (Years)	9 months 18 days
Non-Agency RMBS | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	6 years 1 month 6 days
Outstanding Face	$ 15,285,491
Amortized Cost Basis	932,248
Carrying Value	958,292
SFR Properties
Debt Instrument [Line Items]
Carrying Value	809,708	822,372	357,922
SFR Properties | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	20,534
Carrying Value	$ 20,534	4,677
Weighted Average Funding Cost	8.20%
Weighted Average Life (Years)	1 year
SFR Properties | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Amortized Cost Basis	$ 47,433
Carrying Value	47,433
SFR Properties | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	833,386
Carrying Value	$ 789,174	817,695
Weighted Average Funding Cost	4.10%
Weighted Average Life (Years)	3 years 3 months 18 days
SFR Properties | Secured Notes And Bonds Payable | Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage	3.50%
SFR Properties | Secured Notes And Bonds Payable | Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage	7.10%
SFR Properties | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Amortized Cost Basis	$ 952,923
Carrying Value	952,923
CLOs | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	186,378
Carrying Value	$ 183,947	0
Weighted Average Funding Cost	6.40%
Weighted Average Life (Years)	8 years 10 months 24 days
CLOs | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	8 years 10 months 24 days
Outstanding Face	$ 186,378
Amortized Cost Basis	184,112
Carrying Value	184,112
CLOs | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	30,458
Carrying Value	$ 30,258	0
Weighted Average Funding Cost	7.10%
Weighted Average Life (Years)	6 years 8 months 12 days
CLOs | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	6 years 8 months 12 days
Outstanding Face	$ 30,458
Amortized Cost Basis	30,425
Carrying Value	30,425
Commercial Notes Receivable
Debt Instrument [Line Items]
Carrying Value	317,096	0	0
Commercial Notes Receivable | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	323,452
Carrying Value	$ 317,096	0
Weighted Average Funding Cost	6.50%
Weighted Average Life (Years)	10 months 24 days
Commercial Notes Receivable | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Outstanding Face	$ 429,240
Amortized Cost Basis	364,977
Carrying Value	364,977
Excess MSRs
Debt Instrument [Line Items]
Carrying Value	2,713,933	2,907,300	2,949,526
Excess MSRs | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	181,522
Carrying Value	$ 181,522	227,596
Weighted Average Funding Cost	8.70%
Weighted Average Life (Years)	1 year 9 months 18 days
Excess MSRs | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	6 years 1 month 6 days
Outstanding Face	$ 60,049,904
Amortized Cost Basis	235,395
Carrying Value	272,308
MSRs | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	4,807,776
Carrying Value	$ 4,800,728	4,791,543
Weighted Average Funding Cost	7.50%
Weighted Average Life (Years)	1 year 10 months 24 days
MSRs | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	7 years 6 months
Outstanding Face	$ 522,025,042
Amortized Cost Basis	6,367,520
Carrying Value	8,340,171
Servicer Advance Investments | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	278,845
Carrying Value	$ 278,042	318,445
Weighted Average Funding Cost	7.50%
Weighted Average Life (Years)	2 months 12 days
Servicer Advance Investments | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	8 years 2 months 12 days
Outstanding Face	$ 314,442
Amortized Cost Basis	353,113
Carrying Value	367,803
Servicer Advances | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	2,254,515
Carrying Value	$ 2,254,369	2,361,259
Weighted Average Funding Cost	7.70%
Weighted Average Life (Years)	4 months 24 days
Servicer Advances | Secured Notes And Bonds Payable | Secured Overnight Financing Rate | Minimum
Debt Instrument [Line Items]
Variable interest rate spread	1.50%
Servicer Advances | Secured Notes And Bonds Payable | Secured Overnight Financing Rate | Maximum
Debt Instrument [Line Items]
Variable interest rate spread	3.70%
Servicer Advances | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	8 months 12 days
Outstanding Face	$ 2,856,680
Amortized Cost Basis	2,760,250
Carrying Value	2,760,250
Residential Mortgage Loans | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	650,000
Carrying Value	$ 650,000	769,988
Weighted Average Funding Cost	6.50%
Weighted Average Life (Years)	4 months 24 days
Residential Mortgage Loans | Secured Notes And Bonds Payable | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Variable interest rate spread	1.20%
Residential Mortgage Loans | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	29 years 2 months 12 days
Outstanding Face	$ 649,978
Amortized Cost Basis	651,948
Carrying Value	652,059
Consumer Loans
Debt Instrument [Line Items]
Carrying Value	1,106,974	299,498	458,580
Consumer Loans | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	1,134,666
Carrying Value	$ 1,106,974	299,498
Weighted Average Funding Cost	7.00%
Weighted Average Life (Years)	4 years 2 months 12 days
Consumer Loans | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	1 year 8 months 12 days
Outstanding Face	$ 1,308,774
Amortized Cost Basis	1,269,872
Carrying Value	1,274,005
Mortgage Loans Receivable
Debt Instrument [Line Items]
Carrying Value	1,856,008	1,733,581	$ 1,252,660
Mortgage Loans Receivable | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	524,062
Carrying Value	$ 518,998	512,919
Weighted Average Funding Cost	5.70%
Weighted Average Life (Years)	2 years 9 months 18 days
Face amount of fixed rate debt	$ 238,100
Interest rate, stated percentage	4.60%
Mortgage Loans Receivable | Secured Notes And Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	1 year
Outstanding Face	$ 578,314
Amortized Cost Basis	578,314
Carrying Value	578,314
Secured Facility- Asset Management | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	75,000
Carrying Value	$ 69,121	0
Weighted Average Funding Cost	8.80%
Weighted Average Life (Years)	1 year 9 months 18 days
Liabilities of Consolidated Funds | Liabilities of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 222,250
Carrying Value	$ 218,157	$ 0
Weighted Average Funding Cost	5.00%
Weighted Average Life (Years)	4 years 9 months 18 days
Liabilities of Consolidated Funds | Liabilities of Consolidated Funds | Collateral
Debt Instrument [Line Items]
Outstanding Face	$ 205,723
Carrying Value	203,794
2.5% To 3.7% Agency MSR Secured Note And Bond Payable | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 3,800,000
2.5% To 3.7% Agency MSR Secured Note And Bond Payable | Secured Notes And Bonds Payable | Secured Overnight Financing Rate | Minimum
Debt Instrument [Line Items]
Variable interest rate spread	2.50%
2.5% To 3.7% Agency MSR Secured Note And Bond Payable | Secured Notes And Bonds Payable | Secured Overnight Financing Rate | Maximum
Debt Instrument [Line Items]
Variable interest rate spread	3.70%
3.0% To 5.4% Public Notes | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 1,000,000
3.0% To 5.4% Public Notes | Secured Notes And Bonds Payable | Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage	3.00%
3.0% To 5.4% Public Notes | Secured Notes And Bonds Payable | Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage	5.40%
Consumer Loan, UPB Class A | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 205,200
Interest rate, stated percentage	2.00%
Consumer Loan, UPB Class B | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 53,000
Interest rate, stated percentage	2.70%
Consumer Loan, Marcus | Secured Notes And Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 871,200
Consumer Loan, Marcus | Secured Notes And Bonds Payable | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Variable interest rate spread	3.00%
Consolidated Funds, Notes Payable, Class A | Liabilities of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 120,000
Interest rate, stated percentage	4.30%
Consolidated Funds, Notes Payable, Class B | Liabilities of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 70,000
Interest rate, stated percentage	5.30%
Consolidated Funds, Notes Payable, Class C | Liabilities of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 15,000
Interest rate, stated percentage	6.30%
Subordinated Notes | Liabilities of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 17,300