Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest Income
Interest and fees on loans	$ 150,498	$ 170,012	$ 142,055
Interest on investment securities:
Taxable	23,355	23,389	17,337
Tax-exempt	3,914	2,967	2,843
Interest Income, Deposits with Financial Institutions	492	1,332	1,666
Total Interest Income	178,259	197,700	163,901
Interest Expense
Interest on deposits	22,522	32,666	21,397
Interest on short-term borrowings	993	3,491	3,415
Interest on long-term debt	100	182	880
Total Interest Expense	23,615	36,339	25,692
Net Interest Income	154,644	161,361	138,209
Financing Receivable, Credit Loss, Expense (Reversal)	10,722	(1,250)	(2,310)
Net Interest Income After Provision for (recovery of) Credit Losses	143,922	162,611	140,519
Non-Interest Income
Net gains on sale of investment securities	62	69	0
Equity Securities, FV-NI, Unrealized Gain (Loss)	(863)	888	(90)
Revenue from Contract with Customer, Including Assessed Tax	61,220	63,767	57,453
Bank owned  life insurance	4,424	3,766	3,090
Gain on Sale of Investments	17,837	0	0
Other income	4,692	4,000	2,962
Total Non-Interest Income	82,680	68,490	60,564
Non-Interest Expense
Salaries and employee benefits	62,074	62,138	54,385
Occupancy related expenses	9,765	10,595	9,323
Equipment and software related expenses	10,200	8,964	7,729
FDIC insurance expense	884	638	1,251
Advertising	2,776	3,344	2,974
Bankcard expenses	5,893	5,555	4,503
Postage, delivery, and statement mailings	2,268	2,416	2,157
Office supplies	1,556	1,559	1,319
Legal and professional fees	2,176	2,371	1,847
Telecommunications	2,129	2,455	1,750
Repossessed asset losses, net of expenses	245	634	845
Merger related costs	0	797	13,257
Other expenses	15,324	16,148	11,726
Total Non-Interest Expense	115,290	117,614	113,066
Income Before Income Taxes	111,312	113,487	88,017
Income tax expense	21,717	24,135	18,015
Net Income (Loss) Attributable to Parent	$ 89,595	$ 89,352	$ 70,002
Average shares outstanding, basic	15,975	16,314	15,421
Effect of dilutive securities	20	19	18
Average shares outstanding, diluted	15,995	16,333	15,439
Basic earnings per common share	$ 5.55	$ 5.43	$ 4.50
Diluted earnings per common share	$ 5.55	$ 5.42	$ 4.49
Deposit Account [Member]
Non-Interest Income
Revenue from Contract with Customer, Including Assessed Tax	$ 25,733	$ 31,515	$ 29,704
Debit Card [Member]
Non-Interest Income
Revenue from Contract with Customer, Including Assessed Tax	23,059	21,093	18,369
Fiduciary and Trust [Member]
Non-Interest Income
Revenue from Contract with Customer, Including Assessed Tax	$ 7,736	$ 7,159	$ 6,529