Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total cost	$ 174,967	$ 167,207
Less accumulated depreciation and amortization	(54,465)	(52,348)
Total premises and equipment	120,502	114,859
Land
Property, Plant and Equipment [Line Items]
Total cost	38,584	38,164
Buildings
Property, Plant and Equipment [Line Items]
Total cost	103,232	93,738
Furniture and equipment
Property, Plant and Equipment [Line Items]
Total cost	30,097	33,110
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total cost	$ 3,054	$ 2,195