Fair Values of Financial Instruments - Valuation Methodologies Used for Instruments Measured at Fair Value on Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Quoted Prices in Active Markets for Identical Assets (Level 1) | Impaired Loans (collateral dependent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	$ 0	$ 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	0	0
Significant Other Observable Inputs (Level 2) | Impaired Loans (collateral dependent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	0	0
Significant Other Observable Inputs (Level 2) | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	0	0
Significant Unobservable Inputs (Level 3) | Impaired Loans (collateral dependent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	5,653	11,866
Significant Unobservable Inputs (Level 3) | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	194	657
Fair Value | Impaired Loans (collateral dependent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	5,653	11,866
Fair Value | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	$ 194	$ 657