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	6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2011
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 Terms Of Issuance			The issuance was pursuant to the U.S. Treasurys SBLF program, a $30.0 billion fund established under the Small Business Jobs Act of 2010, which encouraged lending to small businesses by providing capital to qualified community banks with assets less than $10.0 billion.
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 for future periods is set 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 may vary from 1% per annum to 5% per annum for the second through tenth dividend periods, and will be fixed at a rate of 1% per annum to 7% per annum for the eleventh through the eighteenth dividend periods. If the Series B Preferred Stock remains outstanding for more than four-and-one-half years, the dividend rate will be fixed at 9%.
Preferred Stock, Dividend Rate, Percentage	0.00%	0.00%
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.