Loans and Allowance for Credit Losses Troubled Debt Restructuring Modification (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Number of Contracts	53
Recorded Investment	$ 35,006
Default [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	27
Recorded Investment	20,013
Real-estate commercial mortage
Financing Receivable, Modifications [Line Items]
Number of Contracts	20
Recorded Investment	18,821
Real-estate commercial mortage | Default [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	12
Recorded Investment	12,045
Construction - Commercial Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	4
Recorded Investment	8,991
Construction - Commercial Residential [Member] | Default [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	2
Recorded Investment	5,803
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	17
Recorded Investment	3,912
Residential Portfolio Segment [Member] | Default [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	10
Recorded Investment	2,032
Commercial - Secured [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	11
Recorded Investment	3,150
Commercial - Secured [Member] | Default [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	3
Recorded Investment	$ 133