Fair Value Measurements (Schedule Of Estimates Of Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets:
Securities available-for-sale	$ 810,106	$ 721,796
Securities held-to-maturity	50,598	60,706
Marketable Securities	887,632	812,891
Carrying Amount
Assets:
Cash and cash equivalents	140,144	122,991
Securities available-for-sale	810,106	721,796
Securities held-to-maturity	49,036	60,827
Marketable Securities	12,634	11,771
Net loans	3,604,510	3,571,642
Accrued interest receivable	11,569	12,424
Derivative assets	19,310	17,100
Liabilities:
Deposits	4,075,894	3,975,559
Short-term debt	211,255	261,911
Long-term debt	4,056	4,053
Accrued Interest Payable Fair Value Disclosure	2,849	2,630
Derivative liabilities	19,380	16,905
Fair Value
Assets:
Cash and cash equivalents	140,144	122,991
Securities available-for-sale	810,106	721,796
Securities held-to-maturity	50,598	60,706
Marketable Securities	12,634	11,771
Net loans	3,574,435	3,516,557
Accrued interest receivable	11,569	12,424
Derivative assets	19,310	17,100
Liabilities:
Deposits	4,094,493	3,985,534
Short-term debt	211,255	261,911
Long-term debt	4,124	4,115
Accrued Interest Payable Fair Value Disclosure	2,849	2,630
Derivative liabilities	19,380	16,905
Level 1
Assets:
Cash and cash equivalents	140,144	122,991
Securities available-for-sale	0	0
Securities held-to-maturity	0	0
Marketable Securities	7,787	7,365
Net loans	0	0
Accrued interest receivable	11,569	12,424
Derivative assets	0	0
Liabilities:
Deposits	2,711,323	2,622,905
Short-term debt	0	0
Long-term debt	0	0
Accrued Interest Payable Fair Value Disclosure	2,849	2,630
Derivative liabilities	0	0
Level 2
Assets:
Cash and cash equivalents	0	0
Securities available-for-sale	810,106	721,535
Securities held-to-maturity	50,598	60,706
Marketable Securities	4,847	4,406
Net loans	0	0
Accrued interest receivable	0	0
Derivative assets	19,310	17,100
Liabilities:
Deposits	1,383,170	1,362,629
Short-term debt	211,255	261,911
Long-term debt	4,124	4,115
Accrued Interest Payable Fair Value Disclosure	0	0
Derivative liabilities	19,380	16,905
Level 3
Assets:
Cash and cash equivalents	0	0
Securities available-for-sale	0	261
Securities held-to-maturity	0	0
Marketable Securities	0	0
Net loans	3,574,435	3,516,557
Accrued interest receivable	0	0
Derivative assets	0	0
Liabilities:
Deposits	0	0
Short-term debt	0	0
Long-term debt	0	0
Accrued Interest Payable Fair Value Disclosure	0	0
Derivative liabilities	$ 0	$ 0