Revenue From Contracts with Customers (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income		$ 44,521	$ 43,854	$ 43,518	$ 42,468	$ 42,429	$ 42,645	$ 42,635	$ 41,523	$ 174,361	[1]	$ 169,232	[1]	$ 158,062	[1]
Insurance commission and fee income										16,087		16,571		15,658
Bank owned life insurance income	[1]									2,940		3,179		3,174
Net gain on sales of investment securities	[1]									871		54		10
Net gain on mortgage banking activities	[1]									16,442		3,946		3,125
Other income	[2]									5,953		2,619		262
Noninterest income		$ 20,139	$ 21,805	$ 18,000	$ 18,384	$ 16,170	$ 16,599	$ 16,356	$ 16,297	78,328		65,422		60,173
Trust fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										7,703		7,826		7,882
Service charges on deposit accounts
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										4,845		5,946		5,632
Investment advisory commission and fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										15,944		15,940		15,098
Other service fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income	[2]									7,543		9,341		9,332
Banking [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income	[1]									181,082		174,202		163,042
Insurance commission and fee income										0		0		0
Bank owned life insurance income	[1]									2,831		2,849		3,284
Net gain on sales of investment securities	[1]									871		54		10
Net gain on mortgage banking activities	[1]									16,442		3,946		3,125
Other income	[2]									6,140		2,539		417
Noninterest income										37,910		23,748		20,815
Banking [Member] | Trust fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Banking [Member] | Service charges on deposit accounts
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										4,845		5,946		5,632
Banking [Member] | Investment advisory commission and fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Banking [Member] | Other service fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income	[2]									6,781		8,414		8,347
Wealth Management [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income	[1]									8		41		32
Insurance commission and fee income										0		0		0
Bank owned life insurance income	[1]									0		0		0
Net gain on sales of investment securities	[1]									0		0		0
Net gain on mortgage banking activities	[1]									0		0		0
Other income	[2]									0		0		0
Noninterest income										23,814		23,946		23,179
Wealth Management [Member] | Trust fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										7,703		7,826		7,882
Wealth Management [Member] | Service charges on deposit accounts
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Wealth Management [Member] | Investment advisory commission and fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										15,944		15,940		15,098
Wealth Management [Member] | Other service fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income	[2]									167		180		199
Insurance [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income	[1]									0		0		0
Insurance commission and fee income										16,087		16,571		15,658
Bank owned life insurance income	[1]									0		0		0
Net gain on sales of investment securities	[1]									0		0		0
Net gain on mortgage banking activities	[1]									0		0		0
Other income	[2]									0		0		(2)
Noninterest income										16,682		17,318		16,442
Insurance [Member] | Trust fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Insurance [Member] | Service charges on deposit accounts
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Insurance [Member] | Investment advisory commission and fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Insurance [Member] | Other service fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income	[2]									595		747		786
Other Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income	[1]									(6,729)		(5,011)		(5,012)
Insurance commission and fee income										0		0		0
Bank owned life insurance income	[1]									109		330		(110)
Net gain on sales of investment securities	[1]									0		0		0
Net gain on mortgage banking activities	[1]									0		0		0
Other income	[2]									(187)		80		(153)
Noninterest income										(78)		410		(263)
Other Segments [Member] | Trust fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Other Segments [Member] | Service charges on deposit accounts
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Other Segments [Member] | Investment advisory commission and fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income										0		0		0
Other Segments [Member] | Other service fee income
Segment Reporting, Revenue Reconciling Item [Line Items]
Noninterest income	[2]									$ 0		$ 0		$ 0

[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 are described further in the following paragraphs.