Loans and Credit Quality - Past Due Loans And Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	$ 3,440	$ 2,388
Nonaccrual loans	15,210	21,626
Current loans	970,183	935,095
Total financing receivables	988,833	959,109
Less: Unearned origination fees, net of origination costs	(4,487)	(4,156)
Total loans	984,346	954,953
30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	2,483	2,083
Nonaccrual loans	1,329	810
60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	957	53
Nonaccrual loans	324	0
Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	252
Nonaccrual loans	3,597	3,030
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	1,729	743
Nonaccrual loans	12,671	19,917
Current loans	328,020	292,854
Total financing receivables	342,420	313,514
Total loans	341,091	312,254
Commercial | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	872	503
Nonaccrual loans	1,329	810
Commercial | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	857	0
Nonaccrual loans	324	0
Commercial | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	240
Nonaccrual loans	1,287	2,652
Real estate construction one-to-four family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	0	0
Current loans	37,111	31,201
Total financing receivables	37,111	31,201
Total loans	36,828	30,955
Real estate construction one-to-four family | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate construction one-to-four family | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate construction one-to-four family | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate construction other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	90
Nonaccrual loans	0	0
Current loans	72,256	80,003
Total financing receivables	72,256	80,093
Total loans	71,658	79,784
Real estate construction other | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	90
Real estate construction other | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate construction other | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate term owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	1,197	966
Nonaccrual loans	1,694	1,331
Current loans	123,523	129,745
Total financing receivables	126,414	132,042
Total loans	125,795	131,389
Real estate term owner occupied | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	1,197	966
Nonaccrual loans	0	0
Real estate term owner occupied | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	0	0
Real estate term owner occupied | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	1,694	0
Real estate term non-owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	0	0
Current loans	325,720	319,313
Total financing receivables	325,720	319,313
Total loans	324,198	317,808
Real estate term non-owner occupied | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate term non-owner occupied | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate term non-owner occupied | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Real estate term other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	577	0
Current loans	41,462	40,411
Total financing receivables	42,039	40,411
Total loans	41,746	40,101
Real estate term other | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	0
Real estate term other | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	0
Real estate term other | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	577
Consumer secured by 1st deeds of trust
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	324	363
Nonaccrual loans	220	378
Current loans	18,684	21,875
Total financing receivables	19,228	22,616
Total loans	19,234	22,625
Consumer secured by 1st deeds of trust | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	224	363
Nonaccrual loans	0	0
Consumer secured by 1st deeds of trust | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	100	0
Nonaccrual loans	0	0
Consumer secured by 1st deeds of trust | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	0
Nonaccrual loans	0	378
Consumer other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	190	226
Nonaccrual loans	48	0
Current loans	23,407	19,693
Total financing receivables	23,645	19,919
Total loans	23,796	20,037
Consumer other | 30-59 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	190	161
Nonaccrual loans	0
Consumer other | 60-89 Days Past Due Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	53
Nonaccrual loans	0
Consumer other | Greater Than 90 Days Still Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans	0	$ 12
Nonaccrual loans	$ 39