WAREHOUSE AND OTHER LINES OF CREDIT - Warehouse Borrowings (Details) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Line of Credit Facility [Line Items]
Outstanding Balance	$ 4,265,343,000	$ 7,457,199,000
Debt obligations, net	2,427,140,000	1,628,208,000
Finance Servicing Rights
Line of Credit Facility [Line Items]
Debt obligations, net	114,700,000
Warehouse and Revolving Credit Facilities
Line of Credit Facility [Line Items]
Committed Amount	3,050,000,000
Uncommitted Amount	6,800,000,000
Total Facility Amount	9,850,000,000
Outstanding Balance	4,265,343,000	7,457,199,000
Warehouse and Revolving Credit Facilities | Facility 1
Line of Credit Facility [Line Items]
Committed Amount	400,000,000
Uncommitted Amount	1,100,000,000
Total Facility Amount	1,500,000,000
Outstanding Balance	643,618,000	851,088,000
Warehouse and Revolving Credit Facilities | Facility 2
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	600,000,000
Total Facility Amount	600,000,000
Outstanding Balance	160,471,000	295,743,000
Warehouse and Revolving Credit Facilities | Facility 3
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	500,000,000
Total Facility Amount	500,000,000
Outstanding Balance	146,580,000	459,018,000
Warehouse and Revolving Credit Facilities | Facility 4
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	900,000,000
Total Facility Amount	900,000,000
Outstanding Balance	325,842,000	266,230,000
Warehouse and Revolving Credit Facilities | Facility 5
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	200,000,000
Total Facility Amount	200,000,000
Outstanding Balance	852,000	391,000
Warehouse and Revolving Credit Facilities | Facility 6
Line of Credit Facility [Line Items]
Committed Amount	100,000,000
Uncommitted Amount	1,000,000,000
Total Facility Amount	1,100,000,000
Outstanding Balance	149,623,000	583,449,000
Warehouse and Revolving Credit Facilities | Facility 7
Line of Credit Facility [Line Items]
Committed Amount	750,000,000
Uncommitted Amount	750,000,000
Total Facility Amount	1,500,000,000
Outstanding Balance	609,506,000	1,410,367,000
Warehouse and Revolving Credit Facilities | Facility 8
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	750,000,000
Total Facility Amount	750,000,000
Outstanding Balance	148,592,000	361,783,000
Warehouse and Revolving Credit Facilities | Facility 9
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	0
Total Facility Amount	0
Outstanding Balance	0	600,000,000
Warehouse and Revolving Credit Facilities | Facility 10
Line of Credit Facility [Line Items]
Committed Amount	300,000,000
Uncommitted Amount	0
Total Facility Amount	300,000,000
Outstanding Balance	300,000,000	500,000,000
Warehouse and Revolving Credit Facilities | Facility 11
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	500,000,000
Total Facility Amount	500,000,000
Outstanding Balance	76,629,000	263,516,000
Warehouse and Revolving Credit Facilities | Facility 12
Line of Credit Facility [Line Items]
Committed Amount	500,000,000
Uncommitted Amount	0
Total Facility Amount	500,000,000
Outstanding Balance	500,000,000	500,000,000
Warehouse and Revolving Credit Facilities | Facility 13
Line of Credit Facility [Line Items]
Committed Amount	500,000,000
Uncommitted Amount	0
Total Facility Amount	500,000,000
Outstanding Balance	500,000,000	500,000,000
Warehouse and Revolving Credit Facilities | Facility 14
Line of Credit Facility [Line Items]
Committed Amount	0
Uncommitted Amount	500,000,000
Total Facility Amount	500,000,000
Outstanding Balance	203,630,000	365,614,000
Warehouse and Revolving Credit Facilities | Facility 15
Line of Credit Facility [Line Items]
Committed Amount	500,000,000
Uncommitted Amount	0
Outstanding Balance	500,000,000	$ 500,000,000
Securitization Facilities | Facility 15
Line of Credit Facility [Line Items]
Total Facility Amount	$ 500,000,000