Statement of Comprehensive Income (Statement) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net Income (Loss) Attributable to Parent	$ 126,734	$ 148,351	$ 153,945
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	38	(12)	1,754
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	(8,334)	876	(26,875)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax, Total	(8,372)	888	(28,629)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	(6,221)	0	0
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	21,610	(116,867)	(19,537)
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax	27,831	(116,867)	(19,537)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	0	154	492
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	0	52	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax	0	206	492
Other Comprehensive Income (Loss), Net of Tax	36,203	(117,549)	9,584
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest, Total	$ 162,937	$ 30,802	$ 163,529