Impaired Loans and Valuation Allowance for Loan Losses (Details Textual) (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Impaired Loans and Valuation Allowance for Loan Losses (Textual) [Abstract]
Newly identified TDRs	$ 9,600,000
Impaired Loans and Valuation Allowance for Loan Losses (Additional Textual) [Abstract]
Accruing TDRs	44,200,000		71,600,000
Interest income on impaired loans	2,400,000	2,548,000
Loan default period	60 days
Construction and Land Development [Member]
Impaired Loans and Valuation Allowance for Loan Losses (Textual) [Abstract]
Newly identified TDRs	100,000
Commercial Real Estate [Member]
Impaired Loans and Valuation Allowance for Loan Losses (Textual) [Abstract]
Newly identified TDRs	800,000
Residential Real Estate [Member]
Impaired Loans and Valuation Allowance for Loan Losses (Textual) [Abstract]
Newly identified TDRs	4,200,000
Consumer [Member]
Impaired Loans and Valuation Allowance for Loan Losses (Textual) [Abstract]
Newly identified TDRs	$ 100,000