v3.26.3
Accumulated Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income, Changes In (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
AOCI Attributable to Parent, Net of Tax        
Beginning balance, net of tax $ 882,464 $ 807,200 $ 847,615 $ 811,942
Income tax (expense) benefit 15,358 (8,874) 14,415 (4,465)
Ending balance, net of tax 842,884 834,850 842,884 834,850
Unrealized Gains (Losses) on Securities        
AOCI Attributable to Parent, Net of Tax        
Beginning balance, net of tax (77,921) (123,451) (76,311) (112,199)
Other comprehensive (loss) income before reclassifications (78,909) 16,327 (85,289) (2,504)
Reclassification adjustments included in net income 2,032 26,474 6,374 31,061
Income tax (expense) benefit 16,144 (8,989) 16,572 (5,997)
Net current-period other comprehensive income (loss), net of tax (60,733) 33,812 (62,343) 22,560
Ending balance, net of tax (138,654) (89,639) (138,654) (89,639)
Unrealized Gains (Losses) on Derivatives        
AOCI Attributable to Parent, Net of Tax        
Beginning balance, net of tax 2,321 (3) (1,784) 6,303
Other comprehensive (loss) income before reclassifications 3,105 828 8,812 (2,715)
Reclassification adjustments included in net income (34) (1,988) (545) (6,427)
Income tax (expense) benefit (645) 243 (1,736) 1,919
Net current-period other comprehensive income (loss), net of tax 2,426 (917) 6,531 (7,223)
Ending balance, net of tax 4,747 (920) 4,747 (920)
Retirement Plans        
AOCI Attributable to Parent, Net of Tax        
Beginning balance, net of tax (16,467) (18,031) (17,522) (19,002)
Other comprehensive (loss) income before reclassifications 0 0 0 0
Reclassification adjustments included in net income 668 614 2,003 1,844
Income tax (expense) benefit (141) (128) (421) (387)
Net current-period other comprehensive income (loss), net of tax 527 486 1,582 1,457
Ending balance, net of tax (15,940) (17,545) (15,940) (17,545)
Total        
AOCI Attributable to Parent, Net of Tax        
Beginning balance, net of tax (92,067) (141,485) (95,617) (124,898)
Other comprehensive (loss) income before reclassifications (75,804) 17,155 (76,477) (5,219)
Reclassification adjustments included in net income 2,666 25,100 7,832 26,478
Income tax (expense) benefit 15,358 (8,874) 14,415 (4,465)
Net current-period other comprehensive income (loss), net of tax (57,780) 33,381 (54,230) 16,794
Ending balance, net of tax $ (149,847) $ (108,104) $ (149,847) $ (108,104)