Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for loan and lease losses	$ 16,294	$ 15,936
Right-of-use asset - operating leases	6,450
Deferred compensation	4,748	4,692
Identified intangible assets and goodwill	4,319	0
Supplemental Executive Retirement Plans	3,023	2,846
Unrealized loss on investment securities available-for-sale	0	2,737
Net operating loss carryforwards	187	976
Postretirement benefits	458	391
Nonaccrual interest	557	482
Accrued expense	0	372
Restricted stock and stock option plans	751	497
Employee stock ownership plan	83	106
Other	733	331
Total gross deferred tax assets	37,603	29,366
Deferred tax liabilities:
Operating leases - liability	6,450
Identified intangible assets and goodwill	0	2,428
Deferred loan origination costs, net	3,785	3,537
Depreciation	420	789
Unrealized gain on investment securities available-for-sale	622	0
Prepaid expense	110	116
Accrued Expense	122	0
Acquisition fair value adjustments	1,077	1,001
Total gross deferred tax liabilities	12,586	7,871
Net deferred tax asset	$ 25,017	$ 21,495