Reconciliation of changes in the components of OCI (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax		$ (19,705)	$ 3,633	$ 13,435
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax		(6,281)	19,873	7,490
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax		16,055	(50,767)	(19,139)
Other Comprehensive Income (Loss), before Tax [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax		22,336	(70,640)	(26,629)
Change in fair value of securities available for sale, pre tax amount		(42,019)	155,037	29,995
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax		210	5,603	3,414
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax		(536)	635	1,331
Amortization of certain costs included in net periodic retirement costs, pre tax amount		(39)	(39)	(192)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	(312)	6,246	4,937
Total other comprehensive loss, pre tax amount		64,043	(219,431)	(51,687)
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax		(9,593)	36,047	7,073
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax		(59)	(1,575)	(960)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax		151	(179)	(374)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax		(11)	(11)	(54)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	[1]	88	(1,756)	(1,388)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent		(15,786)	54,164	13,175
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax		32,426	(118,990)	(22,922)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent		32,426	(118,990)	(22,922)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax		151	4,028	2,454
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax		(385)	456	957
Amortization of certain costs included in net periodic retirement costs, after tax amount		28	28	138
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	[1]	(224)	4,490	3,549
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		48,257	(165,267)	(38,512)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax		0	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax		0	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, Portion Attributable to Parent		42,019	(155,037)	(29,995)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, before Tax		42,019	(155,037)	(29,995)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax		9,593	(36,047)	(7,073)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax		32,426	(118,990)	(22,922)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax		0	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax		0	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, Portion Attributable to Parent		42,019	(155,037)	(29,995)
Other Comprehensive Income (Loss), Available-for-Sale Securities, Tax, Portion Attributable to Parent, Total		9,593	(36,047)	(7,073)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent		32,426	(118,990)	(22,922)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax		(5,078)	(65,586)	(7,938)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax		1,428	18,452	2,234
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax		(3,650)	(47,134)	(5,704)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax		(27,414)	5,054	18,691
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax		7,709	(1,421)	(5,256)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax		(19,705)	3,633	13,435
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax		22,336	(70,640)	(26,629)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax		6,281	(19,873)	(7,490)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax		16,055	(50,767)	(19,139)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax		210	5,603	3,414
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax		59	1,575	960
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax		151	4,028	2,454
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax		536	(635)	(1,331)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax		151	(179)	(374)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax		385	(456)	(957)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax		39	39	192
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax		11	11	54
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax		28	28	138
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax		(25)	(31)
Other Comprehensive Income (Loss), Defined Benefit Plan, Adjustment for Settlement or Curtailment Gain (Loss), Tax		7	9
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax		(18)	(22)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	312	(6,246)	(4,937)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	[1]	88	(1,756)	(1,388)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	[1]	224	(4,490)	(3,549)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent		64,043	(219,431)	(51,687)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent		15,786	(54,164)	(13,175)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		$ 48,257	$ (165,267)	$ (38,512)

[1] The amortization of prior service costs is included in the computation of net periodic pension costs as disclosed in Note 12 - Employee Benefit Plans within the Notes to the Consolidated Financial Statements in Item 8.