Disclosures About Fair Value of Assets and Liabilities - Valuation Methodologies Used for Instruments Measured at Fair Value on Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Impaired loans (collateral dependent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 5,168	$ 9,576
Impaired loans (collateral dependent) | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,168	9,576
Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	916	859
Other real estate owned | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 916	$ 859