U.S.Treasury Capital Purchase Program Participation (Details) (USD $)	1 Months Ended		3 Months Ended		12 Months Ended
	May 31, 2009	May 15, 2009	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
U.S. Treasury Capital Purchase Program Participation (Textual) [Abstract]
Repurchase price of warrant					$ 7,465,000	$ 0	$ 0
U.S. Treasury Capital Purchase Program Participation (Additional Textual) [Abstract]
Sale of preferred stock and a warrant for common stock	21,000,000
Number of cumulative perpetual preferred stock shares		21,000
Liquidation value of cumulative perpetual preferred stock		$ 1,000
Number of common stock shares available to U.S. Treasury under warrant issued		616,438
Preferred stock, par value
Rate of cumulative dividends for the first five years	5.00%
Rate of cumulative dividends for the remaining period	9.00%
Period of common stock warrant	10 years
Exercise price of common stock warrant		5.11
Discount rate		12.00%
Estimated fair value		15,500,000
Fair value of common stock warrant		900,000
Aggregate fair value for preferred stock and the common stock warrant		16,400,000
Aggregate attributable to the preferred stock		94.60%
Aggregate attributable to the common stock warrants		5.40%
Issuance amount allocated to preferred stock		19,900,000
Issuance amount allocated to common stock warrant		1,100,000
Discount on the preferred stock		1,300,000
Period of reduction in net income available to common shareholders					5 years
Reduction from retained earnings resulting from accelerated discount on preferred Stock				600,000
Amortization period for accelerated discount on preferred stock				5 years
Cash dividend paid by bank to parent company to fund the repurchase of the warrant			7,500,000		774,000		85,000
Reduction in shareholders' equity resulting from repurchase of warrant			7,500,000
Preferred Stock [Member]
U.S. Treasury Capital Purchase Program Participation (Textual) [Abstract]
Direct cost associated with transaction		200,000
Repurchase of Preferred Stock				21,000,000
Stock warrant [Member]
U.S. Treasury Capital Purchase Program Participation (Textual) [Abstract]
Expected dividend yield		1.00%
Risk-free interest rate		1.99%
Expected life		5 years
Expected volatility		53.00%
Weighted average fair value		$ 3.92
Repurchase price of warrant			7,500,000
Maximum [Member]
U.S. Treasury Capital Purchase Program Participation (Textual) [Abstract]
Reduction in net income attributable to common shareholders due to accretion of preferred stock discount		300,000
Minimum [Member]
U.S. Treasury Capital Purchase Program Participation (Textual) [Abstract]
Reduction in net income attributable to common shareholders due to accretion of preferred stock discount		$ 200,000