Investment Securities, Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-Sale:
Amortized Cost	$ 265,594	$ 278,629
Unrealized Gains	233	608
Unrealized Losses	8,106	4,024
Fair Value	257,721	275,213
Debt Securities, Held-to-Maturity:
Debt securities, held-to-maturity, at cost	31,610	32,571
Unrealized Gains	51	101
Unrealized Losses	865	322
Fair Value	30,796	32,350
Equity Securities, Amortized Cost Basis	2,150	2,110
Equity Securities, Accumulated Gross Unrealized Gain, before Tax		100
Equity Securities, Accumulated Gross Unrealized Loss, before Tax		50
Equity securities with a readily determinable fair value, at fair value	2,188	2,160
U.S. Treasury notes [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	2,280	2,283
Unrealized Gains	0	0
Unrealized Losses	78	24
Fair Value	2,202	2,259
U.S. Agency notes [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	83,774	84,837
Unrealized Gains	0	57
Unrealized Losses	3,226	1,633
Fair Value	80,548	83,261
U.S. Agency mortgage-backed securities [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	62,752	68,347
Unrealized Gains	17	33
Unrealized Losses	2,571	1,227
Fair Value	60,198	67,153
Debt Securities, Held-to-Maturity:
Debt securities, held-to-maturity, at cost	0
Fair Value	0
Non-taxable Municipal securities [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	96,853	102,849
Unrealized Gains	112	343
Unrealized Losses	1,933	1,018
Fair Value	95,032	102,174
Debt Securities, Held-to-Maturity:
Debt securities, held-to-maturity, at cost	27,910	28,871
Unrealized Gains	51	101
Unrealized Losses	715	227
Fair Value	27,246	28,745
Taxable Municipal securities [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	19,935	20,313
Unrealized Gains	104	175
Unrealized Losses	298	122
Fair Value	19,741	20,366
Debt Securities, Held-to-Maturity:
Debt securities, held-to-maturity, at cost	3,700	3,700
Unrealized Gains	0	0
Unrealized Losses	150	95
Fair Value	3,550	3,605
Mutual funds [Member]
Debt Securities, Held-to-Maturity:
Equity Securities, Amortized Cost Basis	1,623	1,586
Equity Securities, Accumulated Gross Unrealized Gain, before Tax		2
Equity Securities, Accumulated Gross Unrealized Loss, before Tax		46
Equity securities with a readily determinable fair value, at fair value	1,545	1,542
Trust preferred securities [Member]
Debt Securities, Held-to-Maturity:
Equity Securities, Amortized Cost Basis	49	49
Equity Securities, Accumulated Gross Unrealized Gain, before Tax		1
Equity Securities, Accumulated Gross Unrealized Loss, before Tax		0
Equity securities with a readily determinable fair value, at fair value	50	50
Equity securities [Member]
Debt Securities, Held-to-Maturity:
Equity Securities, Amortized Cost Basis	478	475
Equity Securities, Accumulated Gross Unrealized Gain, before Tax		97
Equity Securities, Accumulated Gross Unrealized Loss, before Tax		4
Equity securities with a readily determinable fair value, at fair value	$ 593	$ 568