Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net earnings		$ 122,360	$ 180,512	$ 242,488	$ 330,918
Other comprehensive income (loss), net of tax:
Unrealized net holding gains (losses) on securities available-for-sale arising during the period		(72,572)	54,076	(682,398)	(37,447)
Income tax (expense) benefit related to unrealized holding gains (losses) arising during the period		19,928	(14,941)	187,386	10,513
Unrealized net holding gains (losses) on securities available-for-sale, net of tax		(52,644)	39,135	(495,012)	(26,934)
Reclassification adjustment for net (gains) losses included in net earnings	[1]	1,209	0	1,105	(101)
Income tax expense (benefit) related to reclassification adjustment		(332)	0	(303)	28
Reclassification adjustment for net (gains) losses included in net earnings, net of tax		877	0	802	(73)
Amortization of Unrealized Net Loss on Securities Transferred From Available-For-Sale to Held-to-Maturity, net of tax		(218,326)	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		(2,507)	0	(2,507)	0
Debt Securities, Held-to-maturity, Transfer, Unrealized Gain (Loss)		(689)	0	(689)	0
Amortization of Unrealized Net Loss on Securities Transferred From Available-For-Sale to Held-to-Maturity, net of tax		1,818	0	1,818	0
Other comprehensive income (loss), net of tax		(268,275)	39,135	(710,718)	(27,007)
Comprehensive income (loss)		$ (145,915)	$ 219,647	$ (468,230)	$ 303,911

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