Participation in the Small Business Lending Fund (SBLF) of the U.S. Treasury Department (U.S. Treasury) (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2011	Sep. 17, 2013
Non-Cumulative Perpetual Series B Preferred Stock Issued, Shares Pursuant To U.S. Treasury's Small Business Lending Fund Program (in shares)			10,000
Non-Cumulative Perpetual Series B Preferred Stock Issued Pursuant To U.S. Treasury's Small Business Lending Fund Program, Liquidation Preference (in dollars per share)			$ 1,000
Proceeds From Issuance Of Non-Cumulative Perpetual Preferred Series B Preferred Stock Pursuant To U.S. Treasury's Small Business Lending Fund Program			$ 10.0
Preferred Stock, Dividend Payment Rate, Variable			The dividend rate, which is calculated on the aggregate liquidation amount, was initially set at 5% per annum based upon the current level of Qualified Small Business Lending (QSBL) by the Bank. The dividend rate in subsequent periods is based upon the percentage change in qualified lending between each dividend period and the baseline QSBL level established at the time the Agreement was entered into. Such dividend rate varies from 1% to 5% per annum for the first two and one-half years through the quarter ending December 31, 2013. For the two year period beginning with the quarter ending March 31, 2014, the dividend rate will be fixed at a rate of 1% to 7% per annum. If the Series B Preferred Stock remains outstanding for more than four-and-one-half years, beginning with the quarter ending March 31, 2016, the dividend rate will be fixed at 9%. The dividend rate was 5.0% and 4.72%, respectively, for the quarters ended September 30, 2013 and 2012. For the two-year period beginning with the quarter ended March 31, 2014, the dividend rate will be fixed at 2.0%.
Preferred Stock, Dividend Rate, Percentage	5.00%	4.72%
Preferred Stock, Redemption Terms			The Corporation may redeem the shares of Series B Preferred Stock, in whole or in part, at any time at a redemption price equal to the sum of the liquidation amount and the per-share amount of any unpaid dividends for the then-current period, subject to any required prior approval by the Corporations primary federal banking regulator. If paid in part, payments are required to be at least 25% of the original proceeds.
Preferred Stock Redemption Shares				5,000
Preferred Stock Redemption Percentage	50.00%
Preferred Stock, Redemption Amount				$ 5.0