Basis of Presentation and Summary of Significant Accounting Policies - Effects of Reclassifications out of Accumulated Other Comprehensive Earnings (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Abstract]
Earnings before income taxes	$ 67,341	$ 78,631
Income tax (expense) benefit	(12,456)	(15,417)
Net earnings	54,885	63,214
Unrealized Gains and Losses on Available-for-Sale Securities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Abstract]
Net realized gains (losses)	(1,063)	(205)
Credit gains (losses) presented within net realized gains	290	40
Earnings before income taxes	(773)	(165)
Income tax (expense) benefit	162	34
Net earnings	$ (611)	$ (131)