DEBT OBLIGATIONS - Information on Outstanding Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Debt obligations, net	$ 2,427,140	$ 1,628,208
Secured debt obligations
Debt Instrument [Line Items]
Debt obligations, net	1,436,684	542,892
Secured debt obligations | Term Notes
Debt Instrument [Line Items]
Debt obligations, net	199,415	199,133
Secured debt obligations | MSR Facilities
Debt Instrument [Line Items]
Debt obligations, net	1,105,630	262,250
Secured debt obligations | Securities financing facilities
Debt Instrument [Line Items]
Debt obligations, net	98,900	66,439
Secured debt obligations | Servicing advance facilities
Debt Instrument [Line Items]
Debt obligations, net	32,739	15,070
Secured debt obligations | Revolving credit facility
Debt Instrument [Line Items]
Debt obligations, net	1,237,269	343,759
Unsecured debt obligations | Senior Notes
Debt Instrument [Line Items]
Debt obligations, net	$ 990,456	$ 1,085,316