Loans (Details 4) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Recorded investment
Loans with no related allowance recorded	$ 15,702,000	$ 14,087,000
Loans with an allowance recorded	13,167,000	15,242,000
Total	28,869,000	29,329,000
Unpaid principal balance
Loans with no related allowance recorded	19,454,000	17,555,000
Loans with an allowance recorded	14,759,000	19,186,000
Total	34,213,000	36,741,000
Related allowance	1,660,000	3,617,000
Average recorded investment
Loans with no related allowance recorded	13,751,000	13,741,000
Loans with an allowance recorded	16,052,000	15,368,000
Total	29,803,000	29,109,000
Additional disclosure
Loans past due more than 90 days or more and still accruing interest	1,615,000	719,000
Recorded investment in non-accrual loans	20,284,000	18,360,000
Commercial and industrial
Recorded investment
Loans with no related allowance recorded	1,246,000	6,735,000
Loans with an allowance recorded	7,215,000	1,932,000
Total	8,461,000	8,667,000
Unpaid principal balance
Loans with no related allowance recorded	1,889,000	7,591,000
Loans with an allowance recorded	7,215,000	5,103,000
Total	9,104,000	12,694,000
Related allowance	682,000	156,000
Average recorded investment
Loans with no related allowance recorded	5,416,000	6,226,000
Loans with an allowance recorded	3,070,000	3,294,000
Total	8,486,000	9,520,000
Additional disclosure
Loans past due more than 90 days or more and still accruing interest	688,000
Recorded investment in non-accrual loans	456,000	1,554,000
Construction and development
Recorded investment
Loans with no related allowance recorded	8,576,000	352,000
Loans with an allowance recorded	1,294,000	10,511,000
Total	9,870,000	10,863,000
Unpaid principal balance
Loans with no related allowance recorded	10,288,000	2,187,000
Loans with an allowance recorded	1,919,000	11,135,000
Total	12,207,000	13,322,000
Related allowance	148,000	2,898,000
Average recorded investment
Loans with no related allowance recorded	2,316,000	2,097,000
Loans with an allowance recorded	9,265,000	5,929,000
Total	11,581,000	8,026,000
Additional disclosure
Recorded investment in non-accrual loans	9,870,000	10,863,000
Real estate mortgage
Recorded investment
Loans with no related allowance recorded	5,878,000	6,996,000
Loans with an allowance recorded	4,572,000	2,799,000
Total	10,450,000	9,795,000
Unpaid principal balance
Loans with no related allowance recorded	7,236,000	7,752,000
Loans with an allowance recorded	5,539,000	2,948,000
Total	12,775,000	10,700,000
Related allowance	744,000	563,000
Average recorded investment
Loans with no related allowance recorded	6,016,000	5,397,000
Loans with an allowance recorded	3,695,000	6,145,000
Total	9,711,000	11,542,000
Additional disclosure
Loans past due more than 90 days or more and still accruing interest	927,000	485,000
Recorded investment in non-accrual loans	9,956,000	5,939,000
Consumer
Recorded investment
Loans with no related allowance recorded	2,000	4,000
Loans with an allowance recorded	86,000
Total	88,000	4,000
Unpaid principal balance
Loans with no related allowance recorded	41,000	25,000
Loans with an allowance recorded	86,000
Total	127,000	25,000
Related allowance	86,000
Average recorded investment
Loans with no related allowance recorded	3,000	21,000
Loans with an allowance recorded	22,000
Total	25,000	21,000
Additional disclosure
Loans past due more than 90 days or more and still accruing interest		234,000
Recorded investment in non-accrual loans	$ 2,000	$ 4,000