Troubled Debt Restructuring (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	$ 1,033		$ 1,033		$ 1,068
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	3,337		3,337		4,107
Impaired Financing Receivable, Trouble Debt Structuring, Total	4,370		4,370		5,175
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	227		227		263
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modification, Number of Contracts	0	5	2	10
Financing Receivable, Modification, Pre-Modification Recorded Investment	0	3,212	562	8,676
Financing Receivable, Modifications, Post-Modifications Recorded Investment	0	2,263	562	6,492
Financing Receivable, Modifications, Subsequent Default [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	1	1	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	1,197	2,386	1,197	2,386
Commercial and Industrial Loans [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	148		148		169
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	0		0		0
Impaired Financing Receivable, Trouble Debt Structuring, Total	148		148		169
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	0		0		0
Construction And Land Development Loans [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	0		0		0
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	1,601		1,601		1,623
Impaired Financing Receivable, Trouble Debt Structuring, Total	1,601		1,601		1,623
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	107		107		129
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modification, Number of Contracts		0		2
Financing Receivable, Modification, Pre-Modification Recorded Investment		0		2,842
Financing Receivable, Modifications, Post-Modifications Recorded Investment		0		1,753
Financing Receivable, Modifications, Subsequent Default [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	1	1	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	1,197	2,386	1,197	2,386
Commercial Real Estate Owner Occupied Loans [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	885		885		899
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	299		299		1,045
Impaired Financing Receivable, Trouble Debt Structuring, Total	1,184		1,184		1,944
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	120		120		134
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modification, Number of Contracts		3		4
Financing Receivable, Modification, Pre-Modification Recorded Investment		2,349		3,167
Financing Receivable, Modifications, Post-Modifications Recorded Investment		1,406		2,225
Commercial Real Estate Other Loans [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	0		0		0
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	429		429		432
Impaired Financing Receivable, Trouble Debt Structuring, Total	429		429		432
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	0		0		0
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modification, Number of Contracts	0	0	1	2
Financing Receivable, Modification, Pre-Modification Recorded Investment	0	0	431	1,804
Financing Receivable, Modifications, Post-Modifications Recorded Investment	0	0	431	1,657
Commercial Real Estate Loans, Total [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	885		885		899
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	728		728		1,477
Impaired Financing Receivable, Trouble Debt Structuring, Total	1,613		1,613		2,376
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	120		120		134
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modification, Number of Contracts	0	3	1	6
Financing Receivable, Modification, Pre-Modification Recorded Investment	0	2,349	431	4,971
Financing Receivable, Modifications, Post-Modifications Recorded Investment	0	1,406	431	3,882
Residential Real Estate Consumer Mortgage Loans [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	0		0		0
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	783		783		819
Impaired Financing Receivable, Trouble Debt Structuring, Total	783		783		819
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	0		0		0
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modification, Number of Contracts	0	2	1	2
Financing Receivable, Modification, Pre-Modification Recorded Investment	0	863	131	863
Financing Receivable, Modifications, Post-Modifications Recorded Investment	0	857	131	857
Residential Real Estate Investment Property Loans [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	0		0		0
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	225		225		188
Impaired Financing Receivable, Trouble Debt Structuring, Total	225		225		188
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	0		0		0
Residential Real Estate Loans, Total [Member]
Impaired Financing Receivable And Troubled Debt Restructing [Line Items]
Impaired Financing Receivable, Troubled Debt Restructuring, Still Accruing	0		0		0
Impaired Financing Receivable, Troubled Debt Restructuring, Nonaccrual	1,008		1,008		1,007
Impaired Financing Receivable, Trouble Debt Structuring, Total	1,008		1,008		1,007
Impaired Financing Receivable, Troubled Debt Restructuring, Allowance for Credit Losses	0		0		0
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modification, Number of Contracts	0	2	1	2
Financing Receivable, Modification, Pre-Modification Recorded Investment	0	863	131	863
Financing Receivable, Modifications, Post-Modifications Recorded Investment	$ 0	$ 857	$ 131	$ 857