Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 420,300	$ (1,523,420)	$ 354,095
Available for sale securities:
Unrealized (losses) gains arising during the period	(124,970)	106,814	86,029
Income tax benefit (expense) related to unrealized gains (losses)	32,142	(27,473)	(22,127)
Reclassification adjustment for net realized (gains) losses in earnings	(8)	(190)	7,184
Income tax expense (benefit) related to realized (gains) losses	2	49	(1,848)
Net change in unrealized (losses) gains for available for sale securities	(92,834)	79,200	69,238
Junior subordinated debentures, at fair value:
Unrealized (losses) gains arising during the period	(37,899)	18,842	25,855
Income tax benefit (expense) related to unrealized gains (losses)	9,747	(4,846)	(6,630)
Net change in unrealized (losses) gains for junior subordinated debentures, at fair value	(28,152)	13,996	19,225
Other comprehensive (loss) income, net of tax	(120,986)	93,196	88,463
Comprehensive income (loss)	$ 299,314	$ (1,430,224)	$ 442,558