Premises and Equipment - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 127,083	$ 122,788
Accumulated depreciation	(71,469)	(65,848)
Total	55,614	56,940
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	8,651	9,018
Premises
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	61,299	60,767
Furniture and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	45,072	41,713
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 12,061	$ 11,290