Loans - Impaired Loan Balances By Portfolio Segment (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Recorded Investment [Abstract]
Impaired loan, with no related allowance, recorded investment	$ 1,788	$ 2,667
Impaired loan, with an related allowance, recorded investment	1,867	1,870
Impaired loan, total, recorded investment	3,655	4,537
Unpaid Principal Balance [Abstract]
Impaired loan, with no related allowance, unpaid principal balance	2,111	2,989
Impaired loan, with an related allowance, unpaid principal balance	1,913	2,018
Impaired loan, total, unpaid principal balance	4,024	5,007
Impaired loan, total, related allowance	32	165
Average Recorded Investment [Abstract]
Impaired loan, with no related allowance, average recorded investment	2,870	3,345
Impaired loan, with related allowance, average recorded investment	1,834	1,911
Impaired loan, total, average recorded investment	4,704	5,256
Interest Income Recognized [Abstract]
Impaired loan, with no related allowance, interest income recognized	5	9
Impaired loan, with related allowance, interest income recognized	33	43
Impaired loan, total, interest income recognized	38	52
Commercial [Member]
Recorded Investment [Abstract]
Impaired loan, with no related allowance, recorded investment	259	7
Impaired loan, with an related allowance, recorded investment	0	0
Impaired loan, total, recorded investment	259	7
Unpaid Principal Balance [Abstract]
Impaired loan, with no related allowance, unpaid principal balance	261	7
Impaired loan, with an related allowance, unpaid principal balance	0	0
Impaired loan, total, unpaid principal balance	261	7
Impaired loan, total, related allowance	0	0
Average Recorded Investment [Abstract]
Impaired loan, with no related allowance, average recorded investment	197	12
Impaired loan, with related allowance, average recorded investment	0	0
Impaired loan, total, average recorded investment	197	12
Interest Income Recognized [Abstract]
Impaired loan, with no related allowance, interest income recognized	5	1
Impaired loan, with related allowance, interest income recognized	0	0
Impaired loan, total, interest income recognized	5	1
Construction and land development [Member]
Recorded Investment [Abstract]
Impaired loan, with no related allowance, recorded investment	260	280
Impaired loan, with an related allowance, recorded investment	415	576
Impaired loan, total, recorded investment	675	856
Unpaid Principal Balance [Abstract]
Impaired loan, with no related allowance, unpaid principal balance	313	325
Impaired loan, with an related allowance, unpaid principal balance	415	577
Impaired loan, total, unpaid principal balance	728	902
Impaired loan, total, related allowance	1	12
Average Recorded Investment [Abstract]
Impaired loan, with no related allowance, average recorded investment	448	448
Impaired loan, with related allowance, average recorded investment	519	593
Impaired loan, total, average recorded investment	967	1,041
Interest Income Recognized [Abstract]
Impaired loan, with no related allowance, interest income recognized	0	0
Impaired loan, with related allowance, interest income recognized	15	34
Impaired loan, total, interest income recognized	15	34
Commercial real estate [Member]
Recorded Investment [Abstract]
Impaired loan, with no related allowance, recorded investment	254	1,520
Impaired loan, with an related allowance, recorded investment	929	1,275
Impaired loan, total, recorded investment	1,183	2,795
Unpaid Principal Balance [Abstract]
Impaired loan, with no related allowance, unpaid principal balance	522	1,797
Impaired loan, with an related allowance, unpaid principal balance	973	1,422
Impaired loan, total, unpaid principal balance	1,495	3,219
Impaired loan, total, related allowance	8	149
Average Recorded Investment [Abstract]
Impaired loan, with no related allowance, average recorded investment	1,146	1,844
Impaired loan, with related allowance, average recorded investment	871	1,297
Impaired loan, total, average recorded investment	2,017	3,141
Interest Income Recognized [Abstract]
Impaired loan, with no related allowance, interest income recognized	0	0
Impaired loan, with related allowance, interest income recognized	12	8
Impaired loan, total, interest income recognized	12	8
Residential [Member]
Recorded Investment [Abstract]
Impaired loan, with no related allowance, recorded investment	353	603
Impaired loan, with an related allowance, recorded investment	509	4
Impaired loan, total, recorded investment	862	607
Unpaid Principal Balance [Abstract]
Impaired loan, with no related allowance, unpaid principal balance	353	603
Impaired loan, with an related allowance, unpaid principal balance	511	4
Impaired loan, total, unpaid principal balance	864	607
Impaired loan, total, related allowance	23	1
Average Recorded Investment [Abstract]
Impaired loan, with no related allowance, average recorded investment	413	723
Impaired loan, with related allowance, average recorded investment	429	4
Impaired loan, total, average recorded investment	842	727
Interest Income Recognized [Abstract]
Impaired loan, with no related allowance, interest income recognized	0	8
Impaired loan, with related allowance, interest income recognized	6	0
Impaired loan, total, interest income recognized	6	8
Home equity [Member]
Recorded Investment [Abstract]
Impaired loan, with no related allowance, recorded investment	661	256
Impaired loan, with an related allowance, recorded investment	0	0
Impaired loan, total, recorded investment	661	256
Unpaid Principal Balance [Abstract]
Impaired loan, with no related allowance, unpaid principal balance	661	256
Impaired loan, with an related allowance, unpaid principal balance	0	0
Impaired loan, total, unpaid principal balance	661	256
Impaired loan, total, related allowance	0	0
Average Recorded Investment [Abstract]
Impaired loan, with no related allowance, average recorded investment	637	316
Impaired loan, with related allowance, average recorded investment	0	0
Impaired loan, total, average recorded investment	637	316
Interest Income Recognized [Abstract]
Impaired loan, with no related allowance, interest income recognized	0	0
Impaired loan, with related allowance, interest income recognized	0	0
Impaired loan, total, interest income recognized	0	0
Consumer [Member]
Recorded Investment [Abstract]
Impaired loan, with no related allowance, recorded investment	1	1
Impaired loan, with an related allowance, recorded investment	14	15
Impaired loan, total, recorded investment	15	16
Unpaid Principal Balance [Abstract]
Impaired loan, with no related allowance, unpaid principal balance	1	1
Impaired loan, with an related allowance, unpaid principal balance	14	15
Impaired loan, total, unpaid principal balance	15	16
Impaired loan, total, related allowance	0	3
Average Recorded Investment [Abstract]
Impaired loan, with no related allowance, average recorded investment	29	2
Impaired loan, with related allowance, average recorded investment	15	17
Impaired loan, total, average recorded investment	44	19
Interest Income Recognized [Abstract]
Impaired loan, with no related allowance, interest income recognized	0	0
Impaired loan, with related allowance, interest income recognized	0	1
Impaired loan, total, interest income recognized	$ 0	$ 1