Summary of Significant Accounting Policies - Changes in the Balance of Each Component of Accumulated Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Changes in the balance of each component of accumulated other comprehensive earnings (loss)
Beginning balance	$ (166,303)
Other comprehensive earnings (loss)	(12,671)	$ 37,707
Ending balance	(178,974)
Unrealized Gains and Losses on Available-for-Sale Securities
Changes in the balance of each component of accumulated other comprehensive earnings (loss)
Beginning balance	(166,303)	(229,076)
Other comprehensive earnings (loss) before reclassifications	(13,275)	36,254
Amounts reclassified from accumulated other comprehensive earnings	604	1,453
Other comprehensive earnings (loss)	(12,671)	37,707
Ending balance	(178,974)	(191,369)
Balance of securities for which an allowance for credit losses has been recognized in net earnings	$ 904	$ 1,841

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount, after tax, of accumulated increase (decrease) in equity from transaction and other event and circumstance from nonowner source.

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Amount, after tax, of accumulated unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) with allowance for credit loss.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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