Consolidated Statements of Income - USD ($)		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest income
Interest and fees on loans and leases		$ 201,347,000	$ 193,105,000	$ 196,983,000
Interest and dividends on investment securities:
Taxable		6,136,000	7,842,000	10,660,000
Exempt from federal income taxes		170,000	678,000	1,420,000
Interest on deposits with other banks		661,000	574,000	2,876,000
Interest and dividends on other earning assets		1,417,000	1,746,000	2,154,000
Total interest income		209,731,000	203,945,000	214,093,000
Interest expense
Interest on demand deposits		5,581,000	7,724,000	18,633,000
Interest on savings deposits		1,114,000	2,057,000	3,660,000
Interest on time deposits		6,178,000	9,835,000	13,276,000
Interest on short-term borrowings		8,000	327,000	1,012,000
Interest on long-term debt and subordinated notes		8,467,000	9,641,000	8,280,000
Total interest expense		21,348,000	29,584,000	44,861,000
Net interest income (expense)	[1]	188,383,000	174,361,000	169,232,000
(Reversal of provision) provision for credit losses		(10,132,000)	40,794,000	8,511,000
Net interest income after provision for credit losses		198,515,000	133,567,000	160,721,000
Disaggregation of Revenue [Line Items]
Insurance commission and fee income		16,357,000	16,087,000	16,571,000
Bank owned life insurance income	[1]	3,981,000	2,940,000	3,179,000
Net gain on sales of investment securities	[1]	145,000	871,000	54,000
Net gain on mortgage banking activities	[1]	15,141,000	16,442,000	3,946,000
Other income	[2]	4,482,000	5,953,000	2,619,000
Total noninterest income		83,224,000	78,328,000	65,422,000
Noninterest expense
Salaries, benefits and commissions		104,191,000	93,208,000	88,289,000
Net occupancy		10,397,000	10,358,000	10,221,000
Equipment		3,899,000	3,841,000	4,170,000
Data processing		12,743,000	11,333,000	10,450,000
Professional fees		7,687,000	5,338,000	5,563,000
Marketing and advertising		2,063,000	1,975,000	2,594,000
Deposit insurance premiums		2,712,000	2,591,000	780,000
Intangible expenses		979,000	1,216,000	1,595,000
Restructuring charges		0	1,439,000	0
Other expense		22,738,000	23,699,000	22,428,000
Total noninterest expense		167,409,000	154,998,000	146,090,000
Income before income taxes		114,330,000	56,897,000	80,053,000
Income tax expense		22,529,000	9,981,000	14,334,000
Net income (loss)		$ 91,801,000	$ 46,916,000	$ 65,719,000
Net income per share:
Basic (in dollars per share)		$ 3.12	$ 1.60	$ 2.24
Diluted (in dollars per share)		$ 3.11	$ 1.60	$ 2.24
Trust fee income
Disaggregation of Revenue [Line Items]
Noninterest income		$ 8,403,000	$ 7,703,000	$ 7,826,000
Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Noninterest income		5,504,000	4,845,000	5,946,000
Investment advisory commission and fee income
Disaggregation of Revenue [Line Items]
Noninterest income		18,936,000	15,944,000	15,940,000
Other service fee income
Disaggregation of Revenue [Line Items]
Noninterest income	[2]	$ 10,275,000	$ 7,543,000	$ 9,341,000

[1] Net interest income as well as many other revenues for financial assets and liabilities including loans, leases, securities, and derivatives are excluded from the scope of FASB ASC 606 "Revenue from Contracts with Customers" (FASB ASC 606). Noninterest income streams that are out of scope of FASB ASC 606 include bank owned life insurance income, sales of investment securities and mortgage banking activities.

[2] Other service fee income and other income include certain items that are in scope and certain items that are out of scope of FASB ASC 606 as described further in the following paragraphs.