DEBT OBLIGATIONS - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Outstanding Face Amount	$ 28,627,042
Carrying Value	$ 28,534,544	$ 23,458,626
Weighted Average Funding Cost	6.30%
Weighted Average Life (Years)	1 year 2 months 12 days
MSR purchase price holdback	$ 144,216	149,552
Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	18,278,569
Carrying Value	$ 18,271,046	12,561,283
Weighted Average Funding Cost	6.00%
Weighted Average Life (Years)	7 months 6 days
MSR purchase price holdback	$ 134,300
Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	10,126,223
Carrying Value	$ 10,045,375	10,679,186
Weighted Average Funding Cost	6.90%
Weighted Average Life (Years)	2 years
Warehouse Credit Facilities-Residential Mortgage Loans | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	$ 3,087,260
Carrying Value	$ 3,087,196	1,940,038
Weighted Average Funding Cost	6.90%
Weighted Average Life (Years)	8 months 12 days
Face amount of debt at fixed rate	$ 224,700
Interest rate	5.00%
Warehouse Credit Facilities-Residential Mortgage Loans | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	28 years 9 months 18 days
Outstanding Face	$ 3,514,478
Amortized Cost Basis of Collateral	3,522,074
Carrying Value	3,438,132
Warehouse Credit Facilities - Mortgage Loans Receivable | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	1,457,135
Carrying Value	$ 1,457,135	1,337,010
Weighted Average Funding Cost	8.10%
Weighted Average Life (Years)	1 year 6 months
Warehouse Credit Facilities - Mortgage Loans Receivable | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	1 year 2 months 12 days
Outstanding Face	$ 1,749,029
Amortized Cost Basis of Collateral	1,761,010
Carrying Value	1,761,010
Agency RMBS or US Treasuries | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	12,557,569
Carrying Value	$ 12,557,569	8,152,469
Weighted Average Funding Cost	5.40%
Weighted Average Life (Years)	4 months 24 days
Agency RMBS or US Treasuries | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	6 years 9 months 18 days
Outstanding Face	$ 12,962,940
Amortized Cost Basis of Collateral	12,773,350
Carrying Value	12,817,767
Non-Agency RMBS | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	645,381
Carrying Value	$ 645,381	610,189
Weighted Average Funding Cost	7.40%
Weighted Average Life (Years)	7 months 6 days
Non-Agency RMBS | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	7 years
Outstanding Face	$ 15,812,493
Amortized Cost Basis of Collateral	974,002
Carrying Value	1,002,578
SFR properties
Debt Instrument [Line Items]
Carrying Value	819,526	809,708
SFR properties | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	27,914
Carrying Value	$ 27,914	20,534
Weighted Average Funding Cost	8.20%
Weighted Average Life (Years)	8 months 12 days
SFR properties | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Amortized Cost Basis of Collateral	$ 60,054
Carrying Value	60,054
SFR properties | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	832,972
Carrying Value	$ 791,612	789,174
Weighted Average Funding Cost	4.10%
Weighted Average Life (Years)	3 years 1 month 6 days
SFR properties | Secured Notes and Bonds Payable | Minimum
Debt Instrument [Line Items]
Interest rate	3.50%
SFR properties | Secured Notes and Bonds Payable | Maximum
Debt Instrument [Line Items]
Interest rate	7.10%
SFR properties | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Amortized Cost Basis of Collateral	$ 946,603
Carrying Value	946,603
CLOs | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	179,858
Carrying Value	$ 178,527	183,947
Weighted Average Funding Cost	6.30%
Weighted Average Life (Years)	8 years 8 months 12 days
CLOs | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	8 years 8 months 12 days
Outstanding Face	$ 180,890
Amortized Cost Basis of Collateral	180,890
Carrying Value	178,475
CLOs | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	19,364
Carrying Value	$ 19,331	30,258
Weighted Average Funding Cost	6.80%
Weighted Average Life (Years)	7 years 3 months 18 days
CLOs | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	7 years 3 months 18 days
Outstanding Face	$ 23,013
Amortized Cost Basis of Collateral	19,541
Carrying Value	22,099
Commercial Notes Receivable
Debt Instrument [Line Items]
Carrying Value	317,324	317,096
Commercial Notes Receivable | Secured Financing Agreements
Debt Instrument [Line Items]
Outstanding Face Amount	323,452
Carrying Value	$ 317,324	317,096
Weighted Average Funding Cost	6.50%
Weighted Average Life (Years)	8 months 12 days
Commercial Notes Receivable | Secured Financing Agreements | Collateral
Debt Instrument [Line Items]
Outstanding Face	$ 429,240
Amortized Cost Basis of Collateral	364,977
Carrying Value	364,977
Excess MSRs
Debt Instrument [Line Items]
Carrying Value	2,594,291	2,713,933
Excess MSRs | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	169,603
Carrying Value	$ 169,603	181,522
Weighted Average Funding Cost	8.80%
Weighted Average Life (Years)	1 year 4 months 24 days
Excess MSRs | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	5 years 9 months 18 days
Outstanding Face	$ 58,577,476
Amortized Cost Basis of Collateral	226,825
Carrying Value	261,420
MSRs | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	4,458,873
Carrying Value	$ 4,452,608	4,800,728
Weighted Average Funding Cost	7.40%
Weighted Average Life (Years)	1 year 8 months 12 days
MSRs | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	7 years 7 months 6 days
Outstanding Face	$ 521,148,213
Amortized Cost Basis of Collateral	6,480,406
Carrying Value	8,657,165
Servicer Advance Investments | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	270,705
Carrying Value	$ 270,705	278,042
Weighted Average Funding Cost	7.30%
Weighted Average Life (Years)	1 year 10 months 24 days
Servicer Advance Investments | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	8 years 4 months 24 days
Outstanding Face	$ 313,271
Amortized Cost Basis of Collateral	352,275
Carrying Value	374,511
Servicer Advances | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	2,154,019
Carrying Value	$ 2,153,983	2,254,369
Weighted Average Funding Cost	7.20%
Weighted Average Life (Years)	1 year 9 months 18 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	$ 2,648,186
Amortized Cost Basis of Collateral	2,586,079
Carrying Value	$ 2,586,079
Residential Mortgage Loans | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Variable interest rate spread	1.20%
Residential Mortgage Loans | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 650,000
Carrying Value	$ 650,000	650,000
Weighted Average Funding Cost	6.80%
Weighted Average Life (Years)	1 month 6 days
Residential Mortgage Loans | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	6 years 8 months 12 days
Outstanding Face	$ 648,077
Amortized Cost Basis of Collateral	665,862
Carrying Value	669,238
Consumer Loans
Debt Instrument [Line Items]
Carrying Value	943,821	1,106,974
Consumer Loans | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	971,627
Carrying Value	$ 943,821	1,106,974
Weighted Average Funding Cost	6.80%
Weighted Average Life (Years)	4 years 1 month 6 days
Consumer Loans | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	1 year 9 months 18 days
Outstanding Face	$ 1,154,642
Amortized Cost Basis of Collateral	1,123,851
Carrying Value	1,103,799
Mortgage Loans Receivable
Debt Instrument [Line Items]
Carrying Value	1,981,195	1,856,008
Mortgage Loans Receivable | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	524,060
Carrying Value	$ 524,060	518,998
Weighted Average Funding Cost	5.70%
Weighted Average Life (Years)	2 years 7 months 6 days
Face amount of debt at fixed rate	$ 238,100
Interest rate	4.60%
Mortgage Loans Receivable | Secured Notes and Bonds Payable | Collateral
Debt Instrument [Line Items]
Weighted Average Life (Years)	7 months 6 days
Outstanding Face	$ 565,996
Amortized Cost Basis of Collateral	565,996
Carrying Value	565,996
Secured Facility- Asset Management | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	75,000
Carrying Value	$ 69,652	69,121
Weighted Average Funding Cost	8.80%
Weighted Average Life (Years)	1 year 7 months 6 days
Notes Payable of Consolidated Funds | Notes Payable of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 222,250
Carrying Value	$ 218,123	$ 218,157
Weighted Average Funding Cost	5.00%
Weighted Average Life (Years)	4 years 7 months 6 days
Notes Payable of Consolidated Funds | Notes Payable of Consolidated Funds | Collateral
Debt Instrument [Line Items]
Outstanding Face	$ 206,141
Carrying Value	204,248
2.5% to 3.5% Agency MSR Secured Note and Bond Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 3,500,000
2.5% to 3.5% Agency MSR Secured Note and Bond Payable | Secured Overnight Financing Rate | Minimum
Debt Instrument [Line Items]
Variable interest rate spread	2.50%
2.5% to 3.5% Agency MSR Secured Note and Bond Payable | Secured Overnight Financing Rate | Maximum
Debt Instrument [Line Items]
Variable interest rate spread	3.70%
3.0% to 5.4% Public Notes
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	3.00%
3.0% to 5.4% Public Notes | Secured Notes and Bonds Payable | Maximum
Debt Instrument [Line Items]
Interest rate	5.40%
Consumer Loan, UPB Class A | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 191,700
Interest rate	2.00%
Consumer Loan, UPB Class B | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 53,000
Interest rate	2.70%
Consumer Loan, Marcus | Secured Notes and Bonds Payable
Debt Instrument [Line Items]
Outstanding Face Amount	$ 721,900,000
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 | Notes Payable of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 120,000
Interest rate	4.30%
Consolidated Funds, Notes Payable, Class B | Notes Payable of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 70,000
Interest rate	6.00%
Consolidated Funds, Notes Payable, Class C | Notes Payable of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 15,000
Interest rate	6.80%
Subordinated Notes | Notes Payable of Consolidated Funds
Debt Instrument [Line Items]
Outstanding Face Amount	$ 17,300