Changes in Accumulated Other Comprehensive Income (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 income by component
Beginning balance	$ 1,904,307	$ 1,628,955	$ 1,890,424	$ 1,596,856
Other comprehensive (loss)/income before reclassification adjustments	(2,924)	2,775	(10,974)	15,377
Amounts reclassified from accumulated other comprehensive income	(794)	(168)	(932)	(337)
Other comprehensive (loss)/income	(3,718)	2,607	(11,906)	15,040
Ending balance	1,927,407	1,642,068	1,927,407	1,642,068
Total
Changes in accumulated other comprehensive income by component
Beginning balance	(78,879)	(98,481)	(70,691)	(110,914)
Other comprehensive (loss)/income	(3,718)	2,607	(11,906)	15,040
Ending balance	(82,597)	(95,874)	(82,597)	(95,874)
Unrealized losses on securities available-for-sale
Changes in accumulated other comprehensive income by component
Beginning balance	(105,241)	(116,385)	(96,126)	(130,248)
Other comprehensive (loss)/income before reclassification adjustments	(3,486)	3,425	(12,594)	17,288
Amounts reclassified from accumulated other comprehensive income	(663)	1	(670)	1
Other comprehensive (loss)/income	(4,149)	3,426	(13,264)	17,289
Ending balance	(109,390)	(112,959)	(109,390)	(112,959)
Other comprehensive income (loss) before reclassification adjustment, tax	1,697	(1,180)	5,127	(5,663)
Amounts reclassified from accumulated other comprehensive income	214	0	216	0
Change in fair value of interest rate swaps
Changes in accumulated other comprehensive income by component
Beginning balance	(164)	(102)	(891)	1,159
Other comprehensive (loss)/income before reclassification adjustments	562	(650)	1,289	(1,911)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Other comprehensive (loss)/income	562	(650)	1,289	(1,911)
Ending balance	398	(752)	398	(752)
Other comprehensive income (loss) before reclassification adjustment, tax	(216)	246	(490)	624
Change in defined benefit pension plans
Changes in accumulated other comprehensive income by component
Beginning balance	26,526	18,006	26,326	18,175
Other comprehensive (loss)/income before reclassification adjustments	0	0	331	0
Amounts reclassified from accumulated other comprehensive income	(131)	(169)	(262)	(338)
Other comprehensive (loss)/income	(131)	(169)	69	(338)
Ending balance	26,395	17,837	26,395	17,837
Other comprehensive income (loss) before reclassification adjustment, tax			(125)
Amounts reclassified from accumulated other comprehensive income	$ 50	$ 64	$ 101	$ 128

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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Amount of tax expense (benefit) allocated to other comprehensive income (loss) before reclassification adjustment from accumulated other comprehensive income (loss).

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