Loans and Allowance for Loan Losses Schedule of Troubled Debt Restructured Loans that Subsequently Defaulted (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012 loans	Sep. 30, 2012 loans
Loans, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts Defaulted in Period	2	2
Financing Receivable, Modifications, Subsequent Default, Recorded Investments, Defaulted in Period	$ 894	$ 894
Commercial loan [Member]
Loans, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts Defaulted in Period	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investments, Defaulted in Period	0	0
Construction, land, and land development [Member]
Loans, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts Defaulted in Period	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investments, Defaulted in Period	0	0
1-4 family residential first mortgages [Member]
Loans, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts Defaulted in Period	1	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investments, Defaulted in Period	74	74
Home equity [Member]
Loans, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts Defaulted in Period	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investments, Defaulted in Period	0	0
Commercial real estate [Member]
Loans, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts Defaulted in Period	1	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investments, Defaulted in Period	820	820
Consumer and other loans [Member]
Loans, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts Defaulted in Period	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investments, Defaulted in Period	$ 0	$ 0