Fair Value of Assets and Liabilities - Valuation Technique (Details) - Level 3 $ in Thousands	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Loans held for branch sale
Valuation techniques and significant unobservable inputs
Loans Held-for-sale, Valuation Technique [Extensible List]		us-gaap:ValuationTechniqueDiscountedCashFlowMember
Loans Held-for-sale, Measurement Input [Extensible List]		us-gaap:MeasurementInputQuotedPriceMember
Loans held for branch sale | Sales contract
Valuation techniques and significant unobservable inputs
Loans held for sale		$ 32,031
Impaired loans | Appraisal value | Property specific adjustment
Valuation techniques and significant unobservable inputs
Impaired loans	$ 3,050	4,022
Foreclosed assets | Appraisal value | Property specific adjustment
Valuation techniques and significant unobservable inputs
Foreclosed assets	$ 84	$ 204
Servicing rights
Valuation techniques and significant unobservable inputs
Servicing Asset, Valuation Technique [Extensible List]	us-gaap:ValuationTechniqueDiscountedCashFlowMember	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Servicing rights | Prepayment speed assumptions
Valuation techniques and significant unobservable inputs
Servicing rights	$ 4,146	$ 4,623
Servicing rights | Prepayment speed assumptions | Minimum
Valuation techniques and significant unobservable inputs
Servicing Asset, Measurement Input	154	104
Servicing rights | Prepayment speed assumptions | Maximum
Valuation techniques and significant unobservable inputs
Servicing Asset, Measurement Input	270	211
Servicing rights | Prepayment speed assumptions | Weighted average
Valuation techniques and significant unobservable inputs
Servicing Asset, Measurement Input	194	130
Servicing rights | Discount rate
Valuation techniques and significant unobservable inputs
Servicing Asset, Measurement Input	0.095	0.105
Servicing rights | Discount rate | Weighted average
Valuation techniques and significant unobservable inputs
Servicing Asset, Measurement Input	0.095	0.105