Loans, Troubled Debt Restructurings Segregated by Class (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Financing Receivable, Modifications [Line Items]
Number of troubled debt restructuring that occurred during the period	5	13	27	33
Post-modification outstanding balance	$ 1,107	$ 7,090	$ 6,142	$ 22,975
Net charge-offs resulting from modification	0	1	0	1
Defaulted restructured loans, number of loans	4	2	14	4
Defaulted Restructured loans, recorded investment	442	3,913	912	3,996
Commercial Construction [Member]
Financing Receivable, Modifications [Line Items]
Number of troubled debt restructuring that occurred during the period	0	5	5	7
Post-modification outstanding balance	0	138	557	3,372
Net charge-offs resulting from modification	0	0	0	0
Defaulted restructured loans, number of loans	0	2	0	2
Defaulted Restructured loans, recorded investment	0	3,913	0	3,913
Commercial Secured By Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of troubled debt restructuring that occurred during the period	2	7	8	17
Post-modification outstanding balance	666	6,949	4,078	17,626
Net charge-offs resulting from modification	0	0	0	0
Defaulted restructured loans, number of loans	2	0	6	0
Defaulted Restructured loans, recorded investment	376	0	800	0
Commercial Other [Member]
Financing Receivable, Modifications [Line Items]
Number of troubled debt restructuring that occurred during the period	2	1	13	9
Post-modification outstanding balance	50	3	1,116	1,977
Net charge-offs resulting from modification	0	1	0	1
Defaulted restructured loans, number of loans	2	0	8	2
Defaulted Restructured loans, recorded investment	66	0	112	83
Real Estate Mortgage [Member]
Financing Receivable, Modifications [Line Items]
Number of troubled debt restructuring that occurred during the period	1		1
Post-modification outstanding balance	391		391
Net charge-offs resulting from modification	$ 0		$ 0