Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Gross premises and equipment	$ 97,098	$ 90,677
Less accumulated depreciation	(50,390)	(45,258)
Total premises and equipment, net of accumulated depreciation	46,708	45,419
Depreciation expense	5,400	4,700	$ 4,700
Land and land improvements
Property, Plant and Equipment [Line Items]
Gross premises and equipment	9,090	8,435
Bank premises and leasehold improvements
Property, Plant and Equipment [Line Items]
Gross premises and equipment	51,312	48,184
Computer software and equipment
Property, Plant and Equipment [Line Items]
Gross premises and equipment	13,953	12,652
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Gross premises and equipment	$ 22,743	$ 21,406