Participation In The U.S. Treasury Capital Purchase Program (CPP) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Dec. 23, 2008
Participation In The U.S. Treasury Capital Repurchase Program [Line Items]
Cumulative perpetual preferred stock issued, value	$ 98,372,000	$ 98,146,000	$ 100,000,000
Liquidation preference per senior preferred shares			$ 1,000
Charge to retained earnings representing preferred stock dividend and accretion of discount	$ 1,500,000
Warrant issued to U.S. Treasury relating to CPP	227,376
Issued warrants as a percentage of senior preferred shares purchased	15.00%
Warrant issued to U.S. treasury relating to CPP, exercise price	$ 65.97
Term of warrants	10 years
Revised Cumulative Dividends Rate [Member]
Participation In The U.S. Treasury Capital Repurchase Program [Line Items]
Preferred stock, dividend rate, percentage	9.00%
Cumulative Dividends Rate [Member]
Participation In The U.S. Treasury Capital Repurchase Program [Line Items]
Preferred stock, dividend rate, percentage	5.00%