Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 117,623	$ 93,361
Less: Accumulated depreciation	36,523	33,036
Premises and equipment, net	81,100	60,325
Depreciation	4,400	3,900	$ 3,900
Land
Property, Plant and Equipment [Line Items]
Total premises and equipment	22,954	21,483
Buildings and building improvements
Property, Plant and Equipment [Line Items]
Total premises and equipment	69,315	50,984
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 25,354	$ 20,894