DEBT OBLIGATIONS - Carrying Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Roll Forward]
Beginning balance	$ 29,237,694	$ 25,191,875
Ending balance	21,356,679	29,237,694
Excess MSRs
Debt Instrument [Roll Forward]
Beginning balance	237,835	275,088
Ending balance	227,596	237,835
MSRs
Debt Instrument [Roll Forward]
Beginning balance	4,234,771	2,691,791
Ending balance	4,791,543	4,234,771
Servicer advances
Debt Instrument [Roll Forward]
Beginning balance	2,711,691	3,008,719
Ending balance	2,679,704	2,711,691
Real Estate Securities
Debt Instrument [Roll Forward]
Beginning balance	9,043,412	13,499,636
Ending balance	7,431,070	9,043,412
Residential mortgage loans and REO
Debt Instrument [Roll Forward]
Beginning balance	10,940,823	5,082,296
Ending balance	3,371,315	10,940,823
Consumer Loans
Debt Instrument [Roll Forward]
Beginning balance	458,580	628,759
Ending balance	299,498	458,580
SFR properties
Debt Instrument [Roll Forward]
Beginning balance	357,922	5,586
Ending balance	822,372	357,922
Mortgage Loans Receivable
Debt Instrument [Roll Forward]
Beginning balance	1,252,660	0
Ending balance	1,733,581	1,252,660
Secured Financing Agreements
Debt Instrument [Roll Forward]
Beginning balance	20,592,884
Acquired borrowings, net of discount		7,090,577
Borrowings	130,455,309	195,904,761
Repayments	(139,791,583)	(199,951,591)
Capitalized deferred financing costs, net of amortization	1,128	1,457
Ending balance	11,257,736	20,592,884
Secured Financing Agreements | Excess MSRs
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	0
Repayments	0	0
Capitalized deferred financing costs, net of amortization	0	0
Secured Financing Agreements | MSRs
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	0
Repayments	0	0
Capitalized deferred financing costs, net of amortization	0	0
Secured Financing Agreements | Servicer advances
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	0
Repayments	0	0
Capitalized deferred financing costs, net of amortization	0	0
Secured Financing Agreements | Real Estate Securities
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	54,385,892	64,749,425
Repayments	(55,998,234)	(69,206,600)
Capitalized deferred financing costs, net of amortization	0	951
Secured Financing Agreements | Residential mortgage loans and REO
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		7,090,577
Borrowings	73,782,327	129,676,976
Repayments	(81,320,424)	(130,719,004)
Capitalized deferred financing costs, net of amortization	1,128	812
Secured Financing Agreements | Consumer Loans
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	0
Repayments	0	0
Capitalized deferred financing costs, net of amortization	0	0
Secured Financing Agreements | SFR properties
Debt Instrument [Roll Forward]
Beginning balance	158,515
Acquired borrowings, net of discount		0
Borrowings	206,595	199,713
Repayments	(360,433)	0
Capitalized deferred financing costs, net of amortization	0	(306)
Ending balance	4,677	158,515
Secured Financing Agreements | Mortgage Loans Receivable
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	2,080,495	1,278,647
Repayments	(2,112,492)	(25,987)
Capitalized deferred financing costs, net of amortization	0	0
Secured Notes and Bonds Payable
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		1,121,772
Borrowings	6,236,323	7,964,077
Repayments	(4,696,138)	(8,078,073)
Discount on borrowings, net of amortization	(42,030)
Unrealized (gain) loss on notes, fair value	(45,791)	(12,991)
Capitalized deferred financing costs, net of amortization	1,767	5,830
Secured Notes and Bonds Payable | Excess MSRs
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	0
Repayments	(10,239)	(37,253)
Discount on borrowings, net of amortization	0
Unrealized (gain) loss on notes, fair value	0	0
Capitalized deferred financing costs, net of amortization	0	0
Secured Notes and Bonds Payable | MSRs
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		1,045,000
Borrowings	2,027,637	4,042,325
Repayments	(1,473,037)	(3,549,148)
Discount on borrowings, net of amortization	0
Unrealized (gain) loss on notes, fair value	0	0
Capitalized deferred financing costs, net of amortization	2,172	4,803
Secured Notes and Bonds Payable | Servicer advances
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		76,772
Borrowings	2,804,677	2,971,974
Repayments	(2,839,257)	(3,346,873)
Discount on borrowings, net of amortization	0
Unrealized (gain) loss on notes, fair value	0	0
Capitalized deferred financing costs, net of amortization	2,593	1,099
Secured Notes and Bonds Payable | Real Estate Securities
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	0
Repayments	0	0
Discount on borrowings, net of amortization	0
Unrealized (gain) loss on notes, fair value	0	0
Capitalized deferred financing costs, net of amortization	0	0
Secured Notes and Bonds Payable | Residential mortgage loans and REO
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	796,849
Repayments	(33,204)	(974,176)
Discount on borrowings, net of amortization	0
Unrealized (gain) loss on notes, fair value	665	(13,435)
Capitalized deferred financing costs, net of amortization	0	(72)
Secured Notes and Bonds Payable | Consumer Loans
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	0	0
Repayments	(123,770)	(170,623)
Discount on borrowings, net of amortization	0
Unrealized (gain) loss on notes, fair value	(35,312)	444
Capitalized deferred financing costs, net of amortization	0	0
Secured Notes and Bonds Payable | SFR properties
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	879,947	152,929
Repayments	(216,631)	0
Discount on borrowings, net of amortization	(42,030)
Unrealized (gain) loss on notes, fair value	0	0
Capitalized deferred financing costs, net of amortization	(2,998)	0
Secured Notes and Bonds Payable | Mortgage Loans Receivable
Debt Instrument [Roll Forward]
Acquired borrowings, net of discount		0
Borrowings	524,062	0
Repayments	0	0
Discount on borrowings, net of amortization	0
Unrealized (gain) loss on notes, fair value	(11,144)	0
Capitalized deferred financing costs, net of amortization	$ 0	$ 0