Borrowed Funds (Summary Of Short-Term Borrowings) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Beginning Balance	$ 193,513		$ 250,499	[1]
Short-term FHLB Advances [Member]
Debt Instrument [Line Items]
Beginning Balance	190,000	$ 225,400	247,000
Average balance outstanding for the period	240,179	193,481	201,712
Maximum balance outstanding at any month end during period	$ 262,000	$ 225,400	$ 247,000
Weighted average interest rate for the period	1.72%	0.84%	1.19%
Weighted average interest rate for balances outstanding	2.02%	1.02%	1.60%
Federal Funds Purchased and Lines of Credit [Member]
Debt Instrument [Line Items]
Beginning Balance	$ 3,513	$ 3,468	$ 3,499
Average balance outstanding for the period	3,506	3,465	3,512
Maximum balance outstanding at any month end during period	$ 3,513	$ 3,468	$ 3,499
Weighted average interest rate for the period	1.50%	0.78%	1.10%
Weighted average interest rate for balances outstanding	1.75%	1.00%	1.50%
Repurchase Agreements [Member]
Debt Instrument [Line Items]
Beginning Balance			$ 0
Average balance outstanding for the period			519
Maximum balance outstanding at any month end during period			$ 0
Weighted average interest rate for the period			0.12%
Weighted average interest rate for balances outstanding			0.00%

[1] Derived from audited consolidated financial statements