Other Comprehensive Income (Loss) - Tax Effects of Components in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Before Tax
Total other comprehensive income	$ 8,239	$ 7,453	$ 21,148	$ 4,527
Tax Effect
Total other comprehensive income	(2,293)	(2,098)	(5,884)	(1,274)
After Tax
Total other comprehensive income	5,946	5,355	15,264	3,253
Unrealized gain (loss) on debt securities available for sale:
Before Tax
Other comprehensive income (loss), before reclassifications	5,889	(626)	21,773	(7,575)
Total other comprehensive income	6,231	(623)	22,101	(8,823)
Tax Effect
Other comprehensive income (loss), before reclassifications	(1,639)	176	(6,058)	2,133
Total other comprehensive income	(1,734)	175	(6,149)	2,484
After Tax
Other comprehensive income (loss), before reclassifications	4,250	(450)	15,715	(5,442)
Total other comprehensive income	4,497	(448)	15,952	(6,339)
Accretion of unrealized (loss) gain on debt securities reclassified as held to maturity
Before Tax
Reclassification from AOCI, current period	6	3	(8)	8
Tax Effect
Reclassification from AOCI, current period	(2)	(1)	2	(2)
After Tax
Reclassification from AOCI, current period	4	2	(6)	6
Reclassification adjustment for (loss) included in net income
Before Tax
Reclassification from AOCI, current period	336	0	336	(1,256)
Tax Effect
Reclassification from AOCI, current period	(93)	0	(93)	353
After Tax
Reclassification from AOCI, current period	243	0	243	(903)
Unrealized (loss) gain on swap contracts accounted for as cash flow hedges
Before Tax
Other comprehensive income (loss), before reclassifications	(1,649)	414	(4,616)	5,647
Tax Effect
Other comprehensive income (loss), before reclassifications	459	(116)	1,285	(1,589)
After Tax
Other comprehensive income (loss), before reclassifications	(1,190)	298	(3,331)	4,058
Total other comprehensive income	(1,190)	298	(3,331)	4,058
Change in funded status of retirement obligations
Before Tax
Other comprehensive income (loss), before reclassifications	3,668	8,224	3,684	8,813
Total other comprehensive income	3,657	7,662	3,663	7,703
Tax Effect
Other comprehensive income (loss), before reclassifications	(1,021)	(2,315)	(1,026)	(2,481)
Total other comprehensive income	(1,018)	(2,157)	(1,020)	(2,169)
After Tax
Other comprehensive income (loss), before reclassifications	2,647	5,909	2,658	6,332
Total other comprehensive income	2,639	5,505	2,643	5,534
Amortization of prior service cost included in net income
Before Tax
Reclassification from AOCI, current period	(34)	(14)	(67)	(28)
Tax Effect
Reclassification from AOCI, current period	9	4	19	8
After Tax
Reclassification from AOCI, current period	(25)	(10)	(48)	(20)
Reclassification adjustment of actuarial net gain (loss) included in net income
Before Tax
Reclassification from AOCI, current period	23	(548)	46	(1,082)
Tax Effect
Reclassification from AOCI, current period	(6)	154	(13)	304
After Tax
Reclassification from AOCI, current period	$ 17	$ (394)	$ 33	$ (778)

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