Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net loss		$ (23,344)	$ 131,616	$ (1,416,182)	$ 374,104
Other comprehensive (loss) income, net of tax:
Unrealized net holding gains (losses) on securities available-for-sale arising during the period		(149,201)	(288,174)	(145,375)	(970,572)
Income tax (expense) benefit related to unrealized holding gains (losses) arising during the period		41,328	79,132	40,268	266,518
Unrealized net holding gains (losses) on securities available-for-sale, net of tax		(107,873)	(209,042)	(105,107)	(704,054)
Reclassification adjustment for net (gains) losses included in net earnings	[1]	0	(86)	0	1,019
Income tax expense (benefit) related to reclassification adjustment		0	24	0	(279)
Reclassification adjustment for net (gains) losses included in net earnings, net of tax		0	(62)	0	740
Amortization of Unrealized Net Loss on Securities Transferred From Available-For-Sale to Held-to-Maturity, net of tax		0	0	0	(218,326)
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), before Tax1		(7,998)	(7,775)	(23,759)	(10,282)
Debt Securities, Held-to-maturity, Transfer, Unrealized Gain (Loss)		(2,215)	(2,135)	(6,581)	(2,824)
Amortization of Unrealized Net Loss on Securities Transferred From Available-For-Sale to Held-to-Maturity, net of tax		5,783	5,640	17,178	7,458
Change In Fair Value of Credit-linked Notes		3,050	0	7,107	0
Income Tax Expense Related to Change In Fair Value of Credit-linked Notes		(839)	0	(1,957)	0
Change In Fair Value of Credit-linked Notes, Net of Tax		2,211	0	5,150	0
Other comprehensive loss, net of tax		(99,879)	(203,464)	(82,779)	(914,182)
Comprehensive loss		$ (123,223)	$ (71,848)	$ (1,498,961)	$ (540,078)

[1] Entire amounts are recognized in "Gain (loss) on sale of securities" on the Condensed Consolidated Statements of Earnings.