v3.26.3
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 9 Months Ended
Sep. 30, 2026
Jun. 30, 2026
Mar. 31, 2026
Sep. 30, 2025
Jun. 30, 2025
Mar. 31, 2025
Sep. 30, 2026
Sep. 30, 2025
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Abstract]                
Earnings before income taxes $ 100,093     $ 157,245     $ 378,122 $ 392,391
Income tax (expense) benefit (19,084)     (32,635)     (74,200) (80,231)
Net earnings 81,009 $ 168,028 $ 54,885 124,610 $ 124,336 $ 63,214 303,922 312,160
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) (1,273)     2,878     (2,843) 1,775
Credit gains (losses) presented within net realized gains (59)     (654)     306 (702)
Earnings before income taxes (1,332)     2,224     (2,537) 1,073
Income tax (expense) benefit 280     (467)     533 (225)
Net earnings $ (1,052)     $ 1,757     $ (2,004) $ 848