Summary of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Income (Loss), Net Of Tax) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 388,187	$ 354,450	$ 305,830
Other Comprehensive Income (Loss)	10,035	(9,709)	2,150
Balance	389,108	388,187	354,450
Unrealized Holding Gains (Losses) On Available-For-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(2,955)
Other Comprehensive Income (Loss)	9,900
Balance	6,945	(2,955)
Unrealized Actuarial Loss On Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(5,696)
Other Comprehensive Income (Loss)	2,442
Balance	(3,254)	(5,696)
Unrealized Losses On Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(789)
Other Comprehensive Income (Loss)	(2,307)
Balance	(3,096)	(789)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(9,440)	546	(1,604)
Other Comprehensive Income (Loss)	10,035	(9,709)	2,150
Balance	$ 595	$ (9,440)	$ 546