Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Changes in the Balance of Each Component of Accumulated Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Changes in the balance of each component of accumulated other comprehensive earnings (loss)
Beginning balance			$ (229,076)				$ (229,076)
Net current-period other comprehensive earnings (loss)	$ (56,834)	$ (19,721)	37,707	$ (81,248)	$ (97,563)	$ (115,581)	(38,848)	$ (294,392)
Ending balance	(267,924)						(267,924)
Unrealized Gains and Losses on Available-for-Sale Securities
Changes in the balance of each component of accumulated other comprehensive earnings (loss)
Beginning balance	(211,090)		$ (229,076)	(163,318)		$ 49,826	(229,076)	49,826
Other comprehensive earnings (loss) before reclassifications	(57,261)			(82,785)			(41,355)	(296,422)
Amounts reclassified from accumulated other comprehensive earnings	427			1,537			2,507	2,030
Net current-period other comprehensive earnings (loss)	(56,834)			(81,248)			(38,848)	(294,392)
Ending balance	(267,924)	$ (211,090)		(244,566)	$ (163,318)		(267,924)	(244,566)
Balance of securities for which an allowance for credit losses has not been recognized in net earnings	$ 2,005			$ 1,520			$ 2,005	$ 1,520