Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Changes in accumulated other comprehensive income by component
Beginning balance	$ 1,927,407	$ 1,642,068	$ 1,890,424	$ 1,596,856
Other comprehensive income/(loss) before reclassification adjustments	(59,015)	8,736	(69,989)	24,113
Amounts reclassified from accumulated other comprehensive income	(289)	(124)	(1,221)	(461)
Other comprehensive (loss)/income	(59,304)	8,612	(71,210)	23,652
Ending balance	1,892,234	1,855,736	1,892,234	1,855,736
Total
Changes in accumulated other comprehensive income by component
Beginning balance	(82,597)	(95,874)	(70,691)	(110,914)
Other comprehensive (loss)/income	(59,304)	8,612	(71,210)	23,652
Ending balance	(141,901)	(87,262)	(141,901)	(87,262)
Unrealized losses on securities available-for-sale
Changes in accumulated other comprehensive income by component
Beginning balance	(109,390)	(112,959)	(96,126)	(130,248)
Other comprehensive income/(loss) before reclassification adjustments	(58,819)	8,820	(71,413)	26,108
Amounts reclassified from accumulated other comprehensive income	(158)	44	(828)	45
Other comprehensive (loss)/income	(58,977)	8,864	(72,241)	26,153
Ending balance	(168,367)	(104,095)	(168,367)	(104,095)
Other comprehensive income (loss) before reclassification adjustment, tax	21,101	(2,826)	26,228	(8,489)
Amounts reclassified from accumulated other comprehensive income	51	(13)	267	(13)
Change in fair value of cash flow hedges
Changes in accumulated other comprehensive income by component
Beginning balance	398	(752)	(891)	1,159
Other comprehensive income/(loss) before reclassification adjustments	(196)	(84)	1,093	(1,995)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Other comprehensive (loss)/income	(196)	(84)	1,093	(1,995)
Ending balance	202	(836)	202	(836)
Other comprehensive income (loss) before reclassification adjustment, tax	75	32	(415)	655
Change in defined benefit pension plans
Changes in accumulated other comprehensive income by component
Beginning balance	26,395	17,837	26,326	18,175
Other comprehensive income/(loss) before reclassification adjustments	0	0	331	0
Amounts reclassified from accumulated other comprehensive income	(131)	(168)	(393)	(506)
Other comprehensive (loss)/income	(131)	(168)	(62)	(506)
Ending balance	26,264	17,669	26,264	17,669
Other comprehensive income (loss) before reclassification adjustment, tax			(125)
Amounts reclassified from accumulated other comprehensive income	$ 50	$ 64	$ 151	$ 191

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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