Loans and Allowances for Credit Losses Loans Part 6 (Details) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 44,268,000	$ 48,126,000
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Renegotiated Residential Mortgage, Loans currently performing	11,000,000	13,000,000
Renegotiated Residential Mortgage Loans, 30 to 89 Days Past	7,000,000	5,800,000
Renegotiated Residents Mortgage Loans, 90 Days or More Past Due	10,000,000	14,000,000
Renegotiated Residential Mortgage, Loans Guaranteed by Government Agencies	25,000,000	29,000,000
Financing Receivable, Modifications, Recorded Investment	$ 28,000,000	$ 33,000,000