Fair Value Measurements, Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		$ 142,981
Securities available-for-sale		142,981	$ 157,121
Loans, net of allowances for loan losses	[1]	766,344	729,092
Loans held for sale		849	779
US Treasury Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		6,818
Obligations of U.S. Government Agencies [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		11,359	9,435
Obligations of State and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		51,241	64,765
Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		68,259	74,296
Money Market Investments [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		1,326	1,194
Recurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		142,981
Securities available-for-sale			157,121
Recurring [Member] | US Treasury Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		6,818
Recurring [Member] | Obligations of U.S. Government Agencies [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		11,359	9,435
Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		51,241	64,765
Recurring [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		68,259	74,296
Recurring [Member] | Money Market Investments [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		1,326	1,194
Recurring [Member] | Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		3,978	7,234
Recurring [Member] | Other Marketable Equity Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Equity securities, available-for-sale			197
Nonrecurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		869
Loans held for sale		849	779
Other real estate owned		251
Nonrecurring [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		118
Nonrecurring [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		133
Nonrecurring [Member] | Mortgage Loans on Real Estate [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses			567
Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Residential 1-4 Family [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		240	264
Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		326
Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		74	74
Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Equity Lines of Credit [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		229	229
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Securities available-for-sale		0	0
Loans, net of allowances for loan losses	[1]	0	0
Loans held for sale		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0
Securities available-for-sale			0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member] | US Treasury Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member] | Obligations of U.S. Government Agencies [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member] | Money Market Investments [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member] | Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member] | Other Marketable Equity Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Equity securities, available-for-sale			0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0
Loans held for sale		0	0
Other real estate owned		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses			0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Residential 1-4 Family [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Equity Lines of Credit [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Securities available-for-sale		142,981	157,121
Loans, net of allowances for loan losses	[1]	0	0
Loans held for sale		849	779
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		142,981
Securities available-for-sale			157,121
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member] | US Treasury Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		6,818
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member] | Obligations of U.S. Government Agencies [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		11,359	9,435
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		51,241	64,765
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		68,259	74,296
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member] | Money Market Investments [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		1,326	1,194
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member] | Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		3,978	7,234
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member] | Other Marketable Equity Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Equity securities, available-for-sale			197
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0
Loans held for sale		849	779
Other real estate owned		118
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		118
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		0
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses			0
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Residential 1-4 Family [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0	0
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0	0
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Equity Lines of Credit [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Securities available-for-sale		0	0
Loans, net of allowances for loan losses	[1]	745,163	722,464
Loans held for sale		0	0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0
Securities available-for-sale			0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member] | US Treasury Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member] | Obligations of U.S. Government Agencies [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member] | Money Market Investments [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member] | Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Debt securities, available-for-sale		0	0
Significant Unobservable Inputs (Level 3) [Member] | Recurring [Member] | Other Marketable Equity Securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Equity securities, available-for-sale			0
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		869
Loans held for sale		0	0
Other real estate owned		133
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		0
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Other real estate owned		133
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses			567
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Residential 1-4 Family [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		240	264
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Commercial [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		326
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Construction [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		74	74
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring [Member] | Mortgage Loans on Real Estate [Member] | Equity Lines of Credit [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract]
Loans, net of allowances for loan losses		$ 229	$ 229

[1] In accordance with the adoption of ASU 2016-01, the fair values of loans held for investment and time deposits as of June 30, 2018 were measured using an exit price notion. The fair values of loans held for investment and time deposits as of December 31, 2017 were measured using an entry price notion.