Other Comprehensive Income (Loss) (Component Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	$ 0	$ 0	$ 0	$ 0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	15,000	113,000	154,000	238,000
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Reclassification Adjustments, after Tax	(45,002,000)	4,858,000	(100,765,000)	(8,739,000)
Other comprehensive loss before reclassifications	(44,987,000)	4,971,000	(100,611,000)	(8,501,000)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	52,000	0	52,000	0
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent	52,000		52,000
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax	67,000	113,000	206,000	238,000
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax	(45,002,000)	4,858,000	(100,765,000)	(8,739,000)
Other comprehensive income (loss)	(44,935,000)	4,971,000	(100,559,000)	(8,501,000)
Changes in pension plan assets and benefit obligations, Net-of-tax amount	(5,792,000)	(34,421,000)	(5,792,000)	(34,421,000)	$ 5,792,000	$ 5,792,000	$ 34,421,000	$ 34,421,000
AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax	0	(460,000)	0	(460,000)	(67,000)	(206,000)	(573,000)	(698,000)
Unrealized gains on available-for-sale securities, Net-of-tax amount	(79,612,000)	31,951,000	(79,612,000)	31,951,000	(34,610,000)	21,153,000	27,093,000	40,690,000
Total accumulated other comprehensive income (loss), Net-of-tax amount	$ (85,404,000)	$ (2,930,000)	(85,404,000)	$ (2,930,000)	$ (40,469,000)	$ 15,155,000	$ (7,901,000)	$ 5,571,000
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent			$ 66,000