Investment Securities (Amortized Cost and Fair Values Classified by Contractual Maturity Date) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Amortized Cost: Due in one year or less	$ 447
Amortized Cost: Due after one year through five years	17,739
Amortized Cost: Due after five years through ten years	22,761
Amortized Cost: Due after ten years	29,536
Amortized Cost, Single Maturity Date, Total	70,483
Fair Value: Due in one year or less	452
Fair Value: Due after one year through five years	17,515
Fair Value: Due after five years through ten years	22,263
Fair Value: Due after ten years	24,965
Fair Value: Single Maturity Date, Total	65,195
Available for sale debt maturities fair value sub total	146,470
Available For Sale Debt Maturities Amortized Cost Total	153,552
Available-for-sale Securities, Amortized Cost Basis	153,552	$ 149,561
Available-for-sale Securities	146,470	140,000
Amortized Cost: Due after one through five years, Held to maturity	8,276
Amortized Cost: Due after five years through ten years, Held to maturity	7,600
Amortized Cost: Due after ten years, Held to maturity	8,510
Amortized Cost: Total, Held to maturity	24,386
Fair Value: Due after one through five years, Held to maturity	8,503
Fair Value: Due after five years through ten years, Held to maturity	7,820
Fair Value: Due after ten years, Held to maturity	9,945
Fair Value: Total, Held to maturity	26,268
Held-to-maturity Securities	93,632	97,169
Held-to-maturity Securities, Fair Value	95,346	97,981
Residential mortgage-backed agencies [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities	47,771	50,384
Held-to-maturity Securities, Fair Value	47,442	50,265
Commercial mortgage-backed agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost: without Single Maturity Date	41,771
Fair Value: without Single Maturity Date	40,891
Available-for-sale Securities, Amortized Cost Basis	41,771	52,978
Available-for-sale Securities	40,891	52,222
Held-to-maturity Securities	17,288	17,584
Held-to-maturity Securities, Fair Value	17,518	17,832
Collateralized mortgage obligations [Member]
Schedule of Investments [Line Items]
Amortized Cost: without Single Maturity Date	41,298
Fair Value: without Single Maturity Date	40,384
Available-for-sale Securities, Amortized Cost Basis	41,298	19,953
Available-for-sale Securities	40,384	19,567
Held-to-maturity Securities	4,187	4,833
Held-to-maturity Securities, Fair Value	$ 4,118	$ 4,684