Loans and the Allowance for Credit Losses (Details 8) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 Default	Mar. 31, 2012 Default
TDRs defaulted later restructured
Number of Defaults	35	14
Recorded Investment	$ 2,922	$ 3,254
Commercial real estate land and construction [Member]
TDRs defaulted later restructured
Number of Defaults		1
Recorded Investment		139
Commercial real estate improved property [Member]
TDRs defaulted later restructured
Number of Defaults	2	10
Recorded Investment	645	2,627
Commercial real estate [Member]
TDRs defaulted later restructured
Number of Defaults	2	11
Recorded Investment	645	2,766
Commercial and industrial [Member]
TDRs defaulted later restructured
Number of Defaults	4	3
Recorded Investment	410	488
Residential real estate [Member]
TDRs defaulted later restructured
Number of Defaults	19
Recorded Investment	1,644
Home equity [Member]
TDRs defaulted later restructured
Number of Defaults	8
Recorded Investment	191
Consumer [Member]
TDRs defaulted later restructured
Number of Defaults	2
Recorded Investment	$ 32