DERIVATIVE INSTRUMENTS - Effect of Other Derivative Contracts on the Consolidated Statements of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Derivative [Line Items]
Unrealized Gain (Loss)	$ (753,601)	$ 900,902
Amount of Gain/(Loss) Recognized in Net Gains (Losses) on Other Derivatives	(372,022)	167,330
Futures
Derivative [Line Items]
Realized Gain (Loss)	9,000
Unrealized Gain (Loss)		1,200
Purchase commitments
Derivative [Line Items]
Realized Gain (Loss)	0	0
Unrealized Gain (Loss)	9,859	(6,613)
Amount of Gain/(Loss) Recognized in Net Gains (Losses) on Other Derivatives	9,859	(6,613)
Net TBA derivatives
Derivative [Line Items]
Realized Gain (Loss)	(14,355)	(8,615)
Unrealized Gain (Loss)	44,533	14,898
Amount of Gain/(Loss) Recognized in Net Gains (Losses) on Other Derivatives	30,178	6,283
Net interest rate swaptions
Derivative [Line Items]
Realized Gain (Loss)	0	0
Unrealized Gain (Loss)	(8,600)	30,631
Amount of Gain/(Loss) Recognized in Net Gains (Losses) on Other Derivatives	(8,600)	30,631
Futures | Futures
Derivative [Line Items]
Realized Gain (Loss)	(86,356)	(8,680)
Unrealized Gain (Loss)	(317,103)	145,709
Amount of Gain/(Loss) Recognized in Net Gains (Losses) on Other Derivatives	$ (403,459)	$ 137,029