Consolidated Statements Of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest Income
Interest and fees on loans	$ 36,872	$ 32,004	$ 104,082	$ 93,223
Interest and dividends on investment securities:
Taxable	4,216	3,666	12,314	10,591
Tax-exempt	701	665	2,114	2,014
Interest on deposits in depository institutions	940	31	1,043	51
Total Interest Income	42,729	36,366	119,553	105,879
Interest Expense
Interest on deposits	5,497	3,796	14,741	10,885
Interest on short-term borrowings	1,435	349	2,354	693
Interest on long-term debt	239	195	680	565
Total Interest Expense	7,171	4,340	17,775	12,143
Net Interest Income	35,558	32,026	101,778	93,736
(Recovery of) provision for loan losses	(27)	1,393	(1,910)	2,584
Net Interest Income After (Recovery of) Provision for Loan Losses	35,585	30,633	103,688	91,152
Non-Interest Income
Net gains on sale of investment securities	0	0	0	4,276
Bank owned life insurance	813	774	2,356	2,972
Other income	1,086	660	3,382	2,303
Total Non-Interest Income	15,753	14,611	45,856	48,043
Non-Interest Expense
Salaries and employee benefits	13,576	12,580	40,368	38,783
Occupancy related expense	2,323	2,426	7,073	7,361
Equipment and software related expense	1,965	1,940	5,691	5,835
FDIC insurance expense	315	328	943	1,031
Advertising	808	689	2,444	2,203
Bankcard expenses	1,134	1,051	3,274	2,964
Postage, delivery, and statement mailings	537	517	1,630	1,576
Office supplies	364	377	1,006	1,082
Legal and professional fees	453	504	1,378	1,393
Telecommunications	408	494	1,349	1,470
Repossessed asset losses, net of expenses	156	107	638	589
Other expenses	3,001	3,296	9,098	8,799
Total Non-Interest Expense	25,040	24,309	74,892	73,086
Income Before Income Taxes	26,298	20,935	74,652	66,109
Income tax expense	5,606	7,003	15,369	21,463
Net Income Available to Common Shareholders	20,692	13,932	59,283	44,646
Total Comprehensive Income	$ 16,367	$ 14,240	$ 44,307	$ 47,881
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Average common shares outstanding, basic (in shares)	15,340	15,485	15,360	15,391
Effect of dilutive securities (in shares)	18	20	20	24
Average common shares outstanding, diluted (in shares)	15,358	15,505	15,380	15,415
Earnings Per Share [Abstract]
Basic earnings per common share (in dollars per share)	$ 1.34	$ 0.89	$ 3.82	$ 2.87
Diluted earnings per common share (in dollars per share)	1.33	0.89	3.82	2.86
Dividends declared per common share (in dollars per share)	$ 0.53	$ 0.44	$ 1.45	$ 1.32
Deposit Account [Member]
Non-Interest Income
Revenue from Contract with Customer	$ 7,598	$ 7,415	$ 21,783	$ 21,219
Debit Card [Member]
Non-Interest Income
Revenue from Contract with Customer	4,677	4,291	13,543	12,804
Fiduciary and Trust [Member]
Non-Interest Income
Revenue from Contract with Customer	$ 1,579	$ 1,471	$ 4,792	$ 4,469