Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest Income
Interest and fees on loans	$ 35,761	$ 42,944	$ 114,813	$ 128,397
Interest and dividends on investment securities:
Taxable	6,266	6,044	17,855	17,465
Tax-exempt	1,132	722	2,659	2,257
Interest on deposits in depository institutions	72	271	432	1,034
Total Interest Income	43,231	49,981	135,759	149,153
Interest Expense
Interest on deposits	5,123	8,585	18,324	24,768
Interest on short-term borrowings	131	814	873	2,729
Interest on long-term debt	0	45	100	140
Total Interest Expense	5,254	9,444	19,297	27,637
Net Interest Income	37,977	40,537	116,462	121,516
Provision for (recovery of) credit losses	1,026	274	10,248	(1,175)
Net Interest Income After Provision for (Recovery of) Credit Losses	36,951	40,263	106,214	122,691
Non-Interest Income
(Losses) gains on sale of investment securities, net	0	(40)	56	69
Unrealized gains (losses) recognized on equity securities still held	461	(214)	(1,698)	(27)
Bank owned  life insurance	1,088	762	3,611	2,910
Sale of VISA shares	0	0	17,837	0
Other income	1,232	765	3,550	3,139
Total Non-Interest Income	16,985	16,698	64,960	50,447
Non-Interest Expense
Salaries and employee benefits	15,361	15,210	46,085	46,220
Occupancy related expense	2,428	2,725	7,318	8,055
Equipment and software related expense	2,607	2,248	7,540	6,662
FDIC insurance expense	355	0	522	639
Advertising	462	861	2,238	2,650
Bankcard expenses	1,517	1,554	4,450	4,270
Postage, delivery, and statement mailings	513	659	1,721	1,828
Office supplies	396	382	1,143	1,167
Legal and professional fees	548	539	1,738	1,665
Telecommunications	547	569	1,589	1,892
Repossessed asset losses (gains), net of expenses	39	(59)	313	410
Merger related costs	0	0	0	797
Other expenses	3,939	3,709	11,992	12,326
Total Non-Interest Expense	28,712	28,397	86,649	88,581
Income Before Income Taxes	25,224	28,564	84,525	84,557
Income tax expense	5,098	6,193	17,151	17,816
Net Income Available to Common Shareholders	$ 20,126	$ 22,371	$ 67,374	$ 66,741
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Average common shares outstanding, basic (in shares)	15,950	16,271	16,065	16,350
Effect of dilutive securities (in shares)	20	18	19	18
Average common shares outstanding, diluted (in shares)	15,970	16,289	16,084	16,368
Earnings Per Share [Abstract]
Basic earnings per common share (in dollars per share)	$ 1.25	$ 1.36	$ 4.15	$ 4.05
Diluted earnings per common share (in dollars per share)	$ 1.25	$ 1.36	$ 4.15	$ 4.04
Service charges
Non-Interest Income
Revenue from contract with customer	$ 6,295	$ 8,183	$ 18,962	$ 23,281
Bankcard revenue
Non-Interest Income
Revenue from contract with customer	6,065	5,440	17,068	15,931
Trust and investment management fee income
Non-Interest Income
Revenue from contract with customer	$ 1,844	$ 1,802	$ 5,574	$ 5,144