Investment Securities, Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-Sale:
Amortized Cost	$ 256,644	$ 278,629
Unrealized Gains	133	608
Unrealized Losses	9,340	4,024
Fair Value	247,437	275,213
Debt Securities, Held-to-Maturity:
Debt securities, held-to-maturity, at cost	31,679	32,571
Unrealized Gains	30	101
Unrealized Losses	1,052	322
Fair Value	30,657	32,350
Equity Securities, Amortized Cost Basis	2,163	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	2,200	2,160
U.S. Treasury notes [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	2,279	2,283
Unrealized Gains	0	0
Unrealized Losses	95	24
Fair Value	2,184	2,259
U.S. Agency notes [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	80,738	84,837
Unrealized Gains	0	57
Unrealized Losses	3,566	1,633
Fair Value	77,172	83,261
U.S. Agency mortgage-backed securities [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	59,734	68,347
Unrealized Gains	8	33
Unrealized Losses	2,950	1,227
Fair Value	56,792	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	93,979	102,849
Unrealized Gains	45	343
Unrealized Losses	2,340	1,018
Fair Value	91,684	102,174
Debt Securities, Held-to-Maturity:
Debt securities, held-to-maturity, at cost	27,979	28,871
Unrealized Gains	30	101
Unrealized Losses	827	227
Fair Value	27,182	28,745
Taxable Municipal securities [Member]
Debt Securities, Available-for-Sale:
Amortized Cost	19,914	20,313
Unrealized Gains	80	175
Unrealized Losses	389	122
Fair Value	19,605	20,366
Debt Securities, Held-to-Maturity:
Debt securities, held-to-maturity, at cost	3,700	3,700
Unrealized Gains	0	0
Unrealized Losses	225	95
Fair Value	3,475	3,605
Mutual funds [Member]
Debt Securities, Held-to-Maturity:
Equity Securities, Amortized Cost Basis	1,633	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	1,547	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	481	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	$ 603	$ 568