Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 72,316	$ 69,798
Less accumulated depreciation	43,296	40,205
Total premises and equipment, net	29,020	29,593
Depreciation expense	3,700	3,400	$ 3,100
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	6,020	6,020
Premises and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	37,913	36,358
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 28,383	$ 27,420