CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Comprehensive income (loss):
Net income (loss)	$ 331,468	$ 367,329	$ 652,380	$ (58,381)
Other comprehensive income:
Unrealized gains (losses) on available-for-sale securities, net	(17,198)	40,470	(82,065)	(97,334)
Reclassification adjustment for net realized losses (gains) included in net income	0	(22,999)	(37,116)	(56,021)
Other comprehensive income (loss)	(17,198)	17,471	(119,181)	(153,355)
Comprehensive income (loss) before preferred stock dividends	314,270	384,800	533,199	(211,736)
Dividends on preferred stock	18,438	18,438	55,313	55,313
Comprehensive income (loss) available to common stock shareholders	$ 295,832	$ 366,362	$ 477,886	$ (267,049)