Loans and Allowance for Credit Losses Modified Under Troubled Debt Restructurings (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	$ 85,508,000	$ 66,175,000
Non-accrual Troubled Debt Restructurings	31,245,000	32,587,000
Total Troubled Debt Restructurings	116,753,000	98,762,000
Loans to Individuals Chapter 7	10,600,000
Charge-offs of Loans to Individuals Chapter 7	3,400,000
Percentage of Current Loans to Individuals Discharged Under Chapter 7	84.00%
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	34,672,000	22,425,000
Real-estate - residential mortgage
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	32,993,000	32,331,000
Construction - Commercial Residential [Member]
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	10,564,000	7,645,000
Commercial - Secured [Member]
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	5,623,000	3,449,000
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	1,518,000	183,000
Commercial - Unsecured [Member]
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	121,000	132,000
Consumer - Direct [Member]
Financing Receivable, Modifications [Line Items]
Total accruing troubled debt restructurings	$ 17,000	$ 10,000