Fair Value Disclosures - Assets and Liabilities Measured on Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired loans	$ 522	$ 769
Foreclosed assets	4,230	3,254
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired loans	0	0
Foreclosed assets	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired loans	0	0
Foreclosed assets	0	0
Significant Other Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired loans	522	769
Foreclosed assets	$ 4,230	$ 3,254