v3.26.1
Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Changes in accumulated other comprehensive (loss) income by component, net of tax        
Beginning balance $ 2,504,781 $ 1,240,182 $ 2,496,061 $ 1,221,939
Other comprehensive income (loss) (3,616) 2,214 (15,075) 9,993
Reclassification adjustment for (income) expense recognized in earnings 98 906 148 3,511
Ending balance 2,539,796 1,254,171 2,539,796 1,254,171
Accumulated Other Comprehensive Income (Loss)        
Changes in accumulated other comprehensive (loss) income by component, net of tax        
Beginning balance (31,411) (42,498) (20,002) (52,882)
Ending balance (34,929) (39,378) (34,929) (39,378)
Investment Securities Available-for-Sale        
Changes in accumulated other comprehensive (loss) income by component, net of tax        
Beginning balance (31,938) (43,981) (20,593) (53,718)
Other comprehensive income (loss) (3,501) 4,327 (14,846) 14,064
Reclassification adjustment for (income) expense recognized in earnings 0 0 0 0
Ending balance (35,439) (39,654) (35,439) (39,654)
Net Change in Fair Value of Cash Flow Hedges        
Changes in accumulated other comprehensive (loss) income by component, net of tax        
Beginning balance (12) (676) 52 (1,323)
Other comprehensive income (loss) (115) (157) (229) (2,115)
Reclassification adjustment for (income) expense recognized in earnings 98 397 148 3,002
Ending balance (29) (436) (29) (436)
Postretirement Benefits        
Changes in accumulated other comprehensive (loss) income by component, net of tax        
Beginning balance 539 2,159 539 2,159
Other comprehensive income (loss) 0 (1,956) 0 (1,956)
Reclassification adjustment for (income) expense recognized in earnings 0 509 0 509
Ending balance $ 539 $ 712 $ 539 $ 712