Premises and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Premises and equipment
Total premises and equipment	$ 118,665,000	$ 116,561,000
Accumulated depreciation and amortization	(69,292,000)	(64,342,000)
Net premises and equipment	49,373,000	52,219,000
Long-lived asset impairment charges	0	0	$ 100,000
Depreciation and amortization of properties and equipment	5,673,000	5,786,000	$ 5,620,000
Land
Premises and equipment
Total premises and equipment	15,505,000	15,222,000
Buildings and improvements
Premises and equipment
Total premises and equipment	60,488,000	59,508,000
Furniture and equipment
Premises and equipment
Total premises and equipment	$ 42,672,000	$ 41,831,000