v3.26.1
Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Changes in accumulated other comprehensive (loss) income by component, net of tax    
Beginning balance $ 2,496,061 $ 1,221,939
Other comprehensive income (loss) (11,457) 9,987
Reclassification adjustment for (income) expense recognized in earnings 48 397
Ending balance 2,504,781 1,240,182
Accumulated Other Comprehensive Income (Loss)    
Changes in accumulated other comprehensive (loss) income by component, net of tax    
Beginning balance (20,002) (52,882)
Ending balance (31,411) (42,498)
Investment Securities Available-for-Sale    
Changes in accumulated other comprehensive (loss) income by component, net of tax    
Beginning balance (20,593) (53,718)
Other comprehensive income (loss) (11,345) 9,737
Reclassification adjustment for (income) expense recognized in earnings 0 0
Ending balance (31,938) (43,981)
Net Change in Fair Value of Cash Flow Hedges    
Changes in accumulated other comprehensive (loss) income by component, net of tax    
Beginning balance 52 (1,323)
Other comprehensive income (loss) (112) 250
Reclassification adjustment for (income) expense recognized in earnings 48 397
Ending balance (12) (676)
Postretirement Benefits    
Changes in accumulated other comprehensive (loss) income by component, net of tax    
Beginning balance 539 2,159
Other comprehensive income (loss) 0 0
Reclassification adjustment for (income) expense recognized in earnings 0 0
Ending balance $ 539 $ 2,159