Loans and the Allowance for Credit Losses (Details 7) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 Contract	Mar. 31, 2012 Contract
Loans identified as TDRs
Number of Modifications	26	10
Pre-Modification Outstanding Recorded Investment	$ 2,605	$ 1,298
Post-Modification Outstanding Recorded Investment	2,388	1,312
Commercial real estate land and construction [Member]
Loans identified as TDRs
Number of Modifications	1
Pre-Modification Outstanding Recorded Investment	299
Post-Modification Outstanding Recorded Investment	299
Commercial Real Estate - Improved Property [Member]
Loans identified as TDRs
Number of Modifications	5	6
Pre-Modification Outstanding Recorded Investment	891	903
Post-Modification Outstanding Recorded Investment	721	909
Commercial real estate [Member]
Loans identified as TDRs
Number of Modifications	6	6
Pre-Modification Outstanding Recorded Investment	1,190	903
Post-Modification Outstanding Recorded Investment	1,020	909
Commercial and industrial [Member]
Loans identified as TDRs
Number of Modifications	6
Pre-Modification Outstanding Recorded Investment	165
Post-Modification Outstanding Recorded Investment	165
Residential real estate [Member]
Loans identified as TDRs
Number of Modifications	7	4
Pre-Modification Outstanding Recorded Investment	1,193	395
Post-Modification Outstanding Recorded Investment	1,155	403
Home equity [Member]
Loans identified as TDRs
Number of Modifications	1
Pre-Modification Outstanding Recorded Investment	2
Post-Modification Outstanding Recorded Investment	2
Consumer [Member]
Loans identified as TDRs
Number of Modifications	6
Pre-Modification Outstanding Recorded Investment	55
Post-Modification Outstanding Recorded Investment	$ 46