CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income/(loss)	$ 80,164	$ (231,581)	$ 328,870
Other Comprehensive Income/(Loss):
Unrealized gains/(losses) on securities available-for-sale	(2,873)	(25,492)	(32,774)
Reclassification adjustment for MBS sales included in net income	(770)	0	0
Changes in fair value of financing agreements at fair value due to changes in instrument-specific credit risk	0	1,255	1,059
Other Comprehensive Income/(Loss)	(3,643)	(24,237)	(31,715)
Comprehensive Income/(Loss) before preferred stock dividends	76,521	(255,818)	297,155
Dividends required on preferred stock	(32,875)	(32,875)	(32,875)
Comprehensive Income/(Loss) Available to Common Stock and Participating Securities	$ 43,646	$ (288,693)	$ 264,280