Fair Value of Assets and Liabilities - Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Level 3 | Loans held for branch sale
Fair value, assets and liabilities measured on recurring and non recurring basis
Loans held for sale		$ 32,031
Non recurring
Fair value, assets and liabilities measured on recurring and non recurring basis
Impaired loans	$ 4,816	4,022
Foreclosed assets	8	84
Servicing rights	3,845	4,623
Non recurring | Loans held for sale
Fair value, assets and liabilities measured on recurring and non recurring basis
Loans held for sale	46,846	14,486
Non recurring | Loans held for branch sale
Fair value, assets and liabilities measured on recurring and non recurring basis
Loans held for sale		32,031
Non recurring | Impaired loans
Fair value, assets and liabilities measured on recurring and non recurring basis
Net impairment	3,138	2,538
Non recurring | Foreclosed assets
Fair value, assets and liabilities measured on recurring and non recurring basis
Net impairment		245
Non recurring | Level 2 | Loans held for sale
Fair value, assets and liabilities measured on recurring and non recurring basis
Loans held for sale	46,846	14,486
Non recurring | Level 3
Fair value, assets and liabilities measured on recurring and non recurring basis
Impaired loans	4,816	4,022
Foreclosed assets	8	84
Servicing rights	$ 3,845	4,623
Non recurring | Level 3 | Loans held for branch sale
Fair value, assets and liabilities measured on recurring and non recurring basis
Loans held for sale		$ 32,031