Loans (Details 4) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Nonperforming loans by class
Nonaccrual	$ 6,733,000	$ 5,855,000	$ 9,546,000
Restructured and loans over 90 days past due and still accruing			1,278,000
Total nonperforming loans	6,733,000	5,855,000	10,824,000
Other restructured loans	163,000	167,000
Total	6,896,000	6,022,000	10,824,000
Aging of past due loans by class of loans
30-59 Days Past Due	6,585,000	3,002,000
60-89 Days Past Due	259,000	195,000
90 Days or Greater Past Due	484,000	3,043,000
Total Past Due	7,328,000	6,240,000
Loans Not Past Due	1,095,060,000	1,082,989,000
Total loan balance	1,102,388,000	1,089,229,000
30 days or greater past due nonaccrual loans	4,406,000	3,130,000
Less than 30 days past due nonaccrual loans held-for-investment	2,327,000	2,725,000
Commercial
Nonperforming loans by class
Nonaccrual	950,000	2,534,000
Total nonperforming loans	950,000	2,534,000
Aging of past due loans by class of loans
30-59 Days Past Due	2,445,000	3,002,000
60-89 Days Past Due	259,000	195,000
90 Days or Greater Past Due	484,000	1,978,000
Total Past Due	3,188,000	5,175,000
Loans Not Past Due	455,310,000	457,228,000
Total loan balance	458,498,000	462,403,000
Real estate
Aging of past due loans by class of loans
Total loan balance	627,690,000	607,959,000
Real estate | Commercial and residential
Nonperforming loans by class
Nonaccrual	4,151,000	1,651,000
Total nonperforming loans	4,151,000	1,651,000
Aging of past due loans by class of loans
30-59 Days Past Due	3,653,000
90 Days or Greater Past Due		1,065,000
Total Past Due	3,653,000	1,065,000
Loans Not Past Due	483,822,000	477,270,000
Total loan balance	487,475,000	478,335,000
Real estate | Land and construction
Nonperforming loans by class
Nonaccrual	1,290,000	1,320,000
Total nonperforming loans	1,290,000	1,320,000
Aging of past due loans by class of loans
Loans Not Past Due	74,972,000	67,980,000
Total loan balance	74,972,000	67,980,000
Real estate | Home equity
Nonperforming loans by class
Nonaccrual	337,000	344,000
Total nonperforming loans	337,000	344,000
Aging of past due loans by class of loans
30-59 Days Past Due	337,000
Total Past Due	337,000
Loans Not Past Due	64,906,000	61,644,000
Total loan balance	65,243,000	61,644,000
Consumer
Nonperforming loans by class
Nonaccrual	5,000	6,000
Total nonperforming loans	5,000	6,000
Aging of past due loans by class of loans
30-59 Days Past Due	150,000
Total Past Due	150,000
Loans Not Past Due	16,050,000	18,867,000
Total loan balance	$ 16,200,000	$ 18,867,000