Premises and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Premises and equipment
Total premises and equipment	$ 115,703,000	$ 114,372,000
Accumulated depreciation and amortization	(63,564,000)	(59,760,000)
Net premises and equipment	52,139,000	54,612,000
Long-lived asset impairment charges	100,000	410,000	$ 0
Depreciation and amortization of properties and equipment	5,620,000	5,658,000	$ 5,245,000
Land
Premises and equipment
Total premises and equipment	15,223,000	15,413,000
Buildings and improvements
Premises and equipment
Total premises and equipment	59,691,000	58,981,000
Furniture and equipment
Premises and equipment
Total premises and equipment	$ 40,789,000	$ 39,978,000