DERIVATIVE FINANCIAL INSTRUMENTS - Effect on the consolidated statements of operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	$ 184,820	$ 5,375	$ 466,394	$ 15,932
Eurodollar Future [Member] | Short [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	0	(7)	0	(14)
Treasury Note Future [Member] | Short [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	84,713	581	207,681	866
Swap [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	65,966	3,000	172,069	12,446
Payer Swaption [Member] | Short [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	(35,239)	2,295	(80,183)	3,507
Payer Swaption [Member] | Long [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	59,131	1,767	150,445	5,477
Interest Rate Floor [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	0	45	0	1,345
TBA Contracts [Member] | Short [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	10,642	(2,306)	14,194	864
TBA Contracts [Member] | Long [Member]
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	106	0	1,200	(8,559)
Interest Rate Cap
Derivatives, Fair Value [Line Items]
(Losses) gains on derivative instruments	$ (499)	$ 0	$ 988	$ 0