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]
Property and equipment	$ 122,003	$ 90,445
Less: accumulated depreciation	43,119	31,444
Total	78,884	59,001
Depreciation expense for premises and equipment	13,300	9,800	$ 7,700
Land
Property, Plant and Equipment [Line Items]
Property and equipment	16,090	13,820
Premises
Property, Plant and Equipment [Line Items]
Property and equipment	20,371	16,697
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	36,634	25,884
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Property and equipment	48,723	33,871
Automobiles
Property, Plant and Equipment [Line Items]
Property and equipment	$ 185	$ 173