Premises and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total premise and equipment	$ 57,322	$ 63,516
Accumulated depreciation and amortization	(19,455)	(24,198)
Total premise and equipment, net	37,867	39,318
Land
Property, Plant and Equipment [Line Items]
Total premise and equipment	2,562	2,596
Furniture And Equipment
Property, Plant and Equipment [Line Items]
Total premise and equipment	8,323	14,912
Tenant Improvements
Property, Plant and Equipment [Line Items]
Total premise and equipment	$ 8,323	8,325
Buildings
Property, Plant and Equipment [Line Items]
Premises and equipment, useful life	39 years
Total premise and equipment	$ 38,114	$ 37,683
Minimum | Furniture And Equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, useful life	3 years
Minimum | Tenant Improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, useful life	2 years
Maximum | Furniture And Equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, useful life	7 years
Maximum | Tenant Improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, useful life	15 years