Accumulated Other Comprehensive Income (Schedule of Changes In Each Component of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 591,993	$ 695,476	$ 681,105	$ 701,106
Other comprehensive (loss) income, net of tax	(61,499)	(7,349)	(159,742)	(16,016)
Ending balance	548,288	677,296	548,288	677,296
Defined Benefit Pension Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(3,485)	(5,661)	(3,485)	(5,661)
Ending balance	(3,485)	(5,661)	(3,485)	(5,661)
Securities available-for-sale:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(80,498)	28,227	17,745	36,894
Other comprehensive loss before reclassifications	(61,499)	(7,349)	(159,742)	(15,779)
Amounts reclassified from other comprehensive income		0		(237)
Other comprehensive (loss) income, net of tax	(61,499)	(7,349)	(159,742)	(16,016)
Ending balance	(141,997)	20,878	(141,997)	20,878
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(83,983)	22,566	14,260	31,233
Other comprehensive loss before reclassifications	(61,499)	(7,349)	(159,742)	(15,779)
Amounts reclassified from other comprehensive income		0		(237)
Other comprehensive (loss) income, net of tax	(61,499)	(7,349)	(159,742)	(16,016)
Ending balance	$ (145,482)	$ 15,217	$ (145,482)	$ 15,217