Summary of Significant Accounting Policies - Changes in the Balance of Each Component of Accumulated Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Changes in the balance of each component of accumulated other comprehensive earnings (loss)
Shareholders' Equity Attributable to Parent, Beginning Balance	$ 1,413,514	$ 1,177,341	$ 1,229,361
Other comprehensive earnings (loss)	(7,420)	62,773	(278,902)
Shareholders' Equity Attributable to Parent, Ending Balance	1,521,967	1,413,514	1,177,341
Balance of securities for which an allowance for credit losses has not been recognized in net earnings	1,492	1,224	1,693
Cumulative Effect, Period of Adoption, Adjustment
Changes in the balance of each component of accumulated other comprehensive earnings (loss)
Shareholders' Equity Attributable to Parent, Beginning Balance		(951)
Shareholders' Equity Attributable to Parent, Ending Balance			(951)
Unrealized Gains and Losses on Available-for-Sale Securities
Changes in the balance of each component of accumulated other comprehensive earnings (loss)
Shareholders' Equity Attributable to Parent, Beginning Balance	(166,303)	(229,076)	49,826
Other comprehensive earnings before reclassifications	(11,501)	59,922	(281,189)
Amounts reclassified from accumulated other comprehensive earnings	4,081	2,851	2,287
Other comprehensive earnings (loss)	(7,420)	62,773	(278,902)
Shareholders' Equity Attributable to Parent, Ending Balance	$ (173,723)	$ (166,303)	$ (229,076)