CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net (loss)/income	$ (231,581)	$ 328,870	$ (679,390)
Other Comprehensive (Loss):
Unrealized (losses)/gains on securities available-for-sale	(25,492)	(32,774)	420,281
Reclassification adjustment for securities sales included in net income	0	0	(389,127)
Reclassification adjustment for impairments included in net income	0	0	(344,269)
Derivative hedging instrument fair value changes, net	0	0	(50,127)
Changes in fair value of financing agreements at fair value due to changes in instrument-specific credit risk	1,255	1,059	(2,314)
Reclassification adjustment for losses/gains related to hedging instruments included in net income	0	0	72,802
Other Comprehensive (Loss)	(24,237)	(31,715)	(292,754)
Comprehensive (loss)/income before preferred stock dividends	(255,818)	297,155	(972,144)
Dividends required on preferred stock	(32,875)	(32,875)	(29,796)
Comprehensive (Loss)/Income Available to Common Stock and Participating Securities	$ (288,693)	$ 264,280	$ (1,001,940)