PREMISES AND EQUIPMENT - Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 107,819	$ 108,944
Less accumulated depreciation and amortization	(52,437)	(49,887)
Premises and equipment, net	55,382	59,057
Depreciation expense	4,600	5,700
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	14,790	15,030
Buildings and improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	53,275	52,955
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	29,736	29,572
Automobiles
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	532	1,596
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	9,024	9,261
Construction-in-process
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 462	$ 530