Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net (loss) earnings		$ (1,899,137)	$ 423,613	$ 606,959
arising during the year		16,525	(952,391)	(146,066)
(losses) arising during the year		(3,938)	262,049	40,677
net of tax		12,587	(690,342)	(105,389)
Reclassification adjustment for net losses (gains) included in net earnings (1)	[1]	442,413	50,321	(1,615)
Income tax (benefit) expense related to reclassification adjustment		(120,797)	(12,397)	449
net earnings, net of tax		321,616	37,924	(1,166)
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), after Tax1		0	(218,326)	0
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), before Tax1		31,895	18,191	0
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), Tax		(8,835)	(4,318)	0
Other comprehensive income (loss), net of tax		358,789	(856,871)	(106,555)
Comprehensive (loss) income		(1,540,348)	(433,258)	500,404
Amortization of Unrealized Net Loss on Securities Transferred From Available-For-Sale to Held-to-Maturity, net of tax		23,060	13,873	0
Change In Fair Value of Credit-linked Notes		7,794	0	0
Income Tax Expense Related to Change In Fair Value of Credit-linked Notes		(2,211)	0	0
Change In Fair Value of Credit-linked Notes, Net of Tax		5,583	0	0
Unrealized Gain (Loss) on Price Risk Cash Flow Derivatives, before Tax		(5,714)	0	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		1,657	0	0
Unrealized Gain (Loss) on Cash Flow Hedging Instruments		$ (4,057)	$ 0	$ 0

[1] Entire amount recognized in "(Loss) gain on sale of securities" on the Consolidated Statements of Earnings (Loss).