Loans and Allowance for Loan Losses, Age Analysis of Past Due Loans Receivable (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Mar. 31, 2011
Age analysis of past due loans receivable [Abstract]
30 to 59 Days Past Due	$ 5,058	$ 4,460
60 to 89 Days Past Due	4,161	709
90 Days or More Past Due	9,232	9,679
Total Past Due	18,451	14,848
Current	431,228	436,518
Loans receivable, ending balance	449,679	451,366
Carrying Amount > 90 Days and Accruing	0	132	132	86
Nonaccruals	10,368	10,650	10,650	4,846
Commercial and Industrial [Member]
Age analysis of past due loans receivable [Abstract]
30 to 59 Days Past Due	349	92
60 to 89 Days Past Due	49	52
90 Days or More Past Due	154	41
Total Past Due	552	185
Current	24,057	26,955
Loans receivable, ending balance	24,609	27,140
Carrying Amount > 90 Days and Accruing	0	0
Nonaccruals	395	643
Commercial Real Estate [Member]
Age analysis of past due loans receivable [Abstract]
30 to 59 Days Past Due	356	0
60 to 89 Days Past Due	0	0
90 Days or More Past Due	7,096	7,712
Total Past Due	7,452	7,712
Current	185,137	185,293
Loans receivable, ending balance	192,589	193,005
Carrying Amount > 90 Days and Accruing	0	0
Nonaccruals	7,265	7,712
Construction and Land [Member]
Age analysis of past due loans receivable [Abstract]
30 to 59 Days Past Due	808	508
60 to 89 Days Past Due	0	250
90 Days or More Past Due	136	136
Total Past Due	944	894
Current	38,970	39,151
Loans receivable, ending balance	39,914	40,045
Carrying Amount > 90 Days and Accruing	0	0
Nonaccruals	136	136
Consumer [Member]
Age analysis of past due loans receivable [Abstract]
30 to 59 Days Past Due	1,786	39
60 to 89 Days Past Due	2,371	10
90 Days or More Past Due	0	5
Total Past Due	4,157	54
Current	8,638	9,507
Loans receivable, ending balance	12,795	9,561
Carrying Amount > 90 Days and Accruing	0	1
Nonaccruals	2	4
Residential Real Estate [Member]
Age analysis of past due loans receivable [Abstract]
30 to 59 Days Past Due	999	2,397
60 to 89 Days Past Due	1,474	397
90 Days or More Past Due	1,282	1,474
Total Past Due	3,755	4,268
Current	131,638	132,322
Loans receivable, ending balance	135,393	136,590
Carrying Amount > 90 Days and Accruing		0
Nonaccruals	2,006	1,927
Home Equity Line of Credit [Member]
Age analysis of past due loans receivable [Abstract]
30 to 59 Days Past Due	760	1,424
60 to 89 Days Past Due	267	0
90 Days or More Past Due	564	311
Total Past Due	1,591	1,735
Current	42,788	43,290
Loans receivable, ending balance	44,379	45,025
Carrying Amount > 90 Days and Accruing		131
Nonaccruals	$ 564	$ 228