Loans - Carrying Amount of Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	$ 10,372	$ 13,571
Unaccreted discount on purchased credit impaired loans	(4,861)	(6,490)
Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total	5,511	7,081
Residential Properties
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	371	451
Commercial Real Estate | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total	3,704	5,463
Commercial and Industrial Loans
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	1,434	1,150
Commercial and Industrial Loans | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total	1,005	809
Consumer Loans
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	9	10
Land | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total	802	809
Real Estate Loans
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	8,929	12,411
Real Estate Loans | Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	7,477	10,871
Real Estate Loans | Land
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	$ 1,081	$ 1,089